BHT-206-SI-2054

SERVICE INSTRUCTION
FOR
HIGH ALTITUDE TAIL ROTOR
KIT
NOTICE
Revision 2 updates Chapters 1 and 2.

EFFECTIVITY

KIT NUMBER MODEL SERIAL NUMBER

1 2 206-704-722-101 206L4 52001 and Subsequent

1 3 206-704-722-111 206L4 52001 and Subsequent

1 3 206-704-722-113 206L4 52215 and Subsequent

1 206-704-722-117 206L4 52215 and Subsequent

1 Blind Encoder Kit 206-706-051-103 must be installed per BHT-206-SI-2055 prior to or

concurrently with this kit. Encoding Altimeter Kit 206-706-007-101 may be installed in lieu of
Blind Encoder Kit.

2 Replaced by 206-704-722-111/-113.

3 Replaced by 206-704-722-117.

COPYRIGHT NOTICE
COPYRIGHT 2011
BELL ® HELICOPTER TEXTRON INC.
AND BELL HELICOPTER TEXTRON
CANADA LTD.
ALL RIGHTS RESERVED

REISSUE — 8 DECEMBER 2004

REVISION 2 — 9 JUNE 2011
BHT-206-SI-2054

PROPRIETARY RIGHTS NOTICE

These data are proprietary to Bell Helicopter Textron Inc. Disclosure,

reproduction, or use of these data for any purpose other than helicopter
operation or maintenance is forbidden without prior written authorization from
Bell Helicopter Textron Inc.

DESTINATION CONTROL STATEMENT

These commodities, technology, or software were exported from the United

States in accordance with the Export Administration Regulations (EAR).
Diversion contrary to U.S. law prohibited. The data contained in this manual are
classified as ECCN EAR99.

Additional copies of this publication may be obtained by contacting:

Commercial Publication Distribution Center
Bell Helicopter Textron Inc.
P. O. Box 482
Fort Worth, Texas 76101-0482

PN Rev. 1 16 NOV 2009

 BHT-206-SI-2054

LOG OF REVISIONS

Insert latest revision pages and dispose of superseded ones.

On a revised page, the text and/or illustration affected by the latest revision is shown by a vertical line. A revised
page with only a vertical line next to the page number indicates that text has shifted or that non-technical
correction(s) were made on that page.

Original ........................... 0......................... 16 DEC 76 Reissue........................... 0......................... 08 DEC 04

Reissue........................... 0.......................... 12 JAN 96 Revision.......................... 1......................... 16 NOV 09
Revision.......................... 1......................... 21 AUG 96 Revision.......................... 2.......................... 09 JUN 11
Revision.......................... 2.........................06 MAR 98

LOG OF PAGES

Page No. Rev No. Page No. Rev No.

Title .............................................................................2 2-27 ............................................................................ 2

PN...............................................................................1 2-28 – 2-47 ................................................................. 1
A/B ..............................................................................2 2-48 ............................................................................ 2
i/ii ................................................................................1 2-48A/2-48B ............................................................... 2
Help ............................................................................1 2-49 ............................................................................ 2
Customer Feedback ...................................................2 2-50 ............................................................................ 1
1-1/1-2 ........................................................................0 2-51 – 2-52 ................................................................. 2
1-3 – 1-7 .....................................................................0 2-52A – 2-52B ............................................................ 2
1-8 ..............................................................................1 2-53 – 2-58 ................................................................. 2
1-9 – 1-10 ...................................................................0 2-58A – 2-58B ............................................................ 2
1-11 – 1-16..................................................................2 2-59 – 2-61 ................................................................. 2
1-17 – 1-20 .................................................................0 2-62 ............................................................................ 1
1-21 – 1-24 .................................................................2 2-63 – 2-64 ................................................................. 2
1-25 – 1-36 .................................................................0 2-64A/2-64B ............................................................... 2
1-37/1-38 ....................................................................0 2-65 – 2-85 ................................................................. 1
1-39/1-40 ....................................................................0 2-86 – 2-88 ................................................................. 2
1-41 – 1-46 .................................................................0 2-89 – 2-123 ............................................................... 1
1-47 – 1-52 .................................................................2 2-124 – 2-125 ............................................................. 2
1-53 – 1-58 .................................................................0 2-126 – 2-133 ............................................................. 1
2-1 – 2-4 .....................................................................2 2-134 – 2-136 ............................................................. 2
2-5/2-6 ........................................................................2 2-137/2-138 ................................................................ 2
2-7 – 2-8 .....................................................................1 3-1/3-2 ........................................................................ 0
2-9 – 2-10 ...................................................................2 3-3 – 3-40 ................................................................... 0
2-11 – 2-12..................................................................1 3-41 ............................................................................ 2
2-13 – 2-14 .................................................................2 3-42 – 3-48 ................................................................. 0
2-15 – 2-26 .................................................................1

LIST OF CHAPTERS

Chapter Description Page

1 Installation Procedures ................................................................................................. 1-1

2 Operation and Maintenance ......................................................................................... 2-1
3 Parts Information and Kit Inventory .............................................................................. 3-1

9 JUN 2011 Rev. 2 A/B

 BHT-206-SI-2054

APPROVAL AND VERIFICATION

The Engineering aspects of this document are Transport Canada approved.

Kit 206-704-722-101 has been verified by first article installation on Model 206L4, S/N 52053, dated 30 November
1994.

Kit 206-704-722-111 has been verified by similarity to kit 206-704-722-101.

Kit 206-704-722-113 has been verified by similarity to kit 206-704-722-111.

Kit 206-704-722-117 has been verified by similarity to kit 206-704-722-113.

ECCN EAR99 16 NOV 2009 Rev. 1 i/ii

 H ELP

E VALUATE

L OGISTICS

P UBLICATIONS

Have you found something wrong with this manual — an

error, an inconsistency, unclear instructions, etc.? Although
we strive for accuracy and clarity, we may make errors on
occasion. If we do and you discover it, we would appreciate
your telling us about it so that we can change whatever is
incorrect or unclear. Please be as specific as possible.

Your complaint or suggestion will be acknowledged and we

will tell you what we intend to do.

You may use the enclosed Customer Feedback form, as

applicable, to inform us where we have erred.

Your assistance is sincerely appreciated.

 CUSTOMER FEEDBACK
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 BHT-206-SI-2054

CHAPTER 1 - INSTALLATION PROCEDURES

TABLE OF CONTENTS

Paragraph Page
Number Title Number

1-1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1-2 Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1-3 Tail Rotor Hub and Blade Assembly and Tail Rotor Gearbox - Modification . . . . . . 1-5
1-4 Tail Rotor Hub and Blade Assembly - Removal . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1-5 Tail Rotor Gearbox - Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1-6 Tail Rotor Gearbox Output Shaft - Installation . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1-7 Installation - Tail Rotor Gearbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
1-8 Tail Rotor Hub and Blade Assembly - Installation . . . . . . . . . . . . . . . . . . . . . . . . 1-12
1-9 Tail Rotor Pitch Change Mechanism - Installation . . . . . . . . . . . . . . . . . . . . . . . 1-12
1-10 Directional Control System - Modification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
1-11 Electrical Installation - Directional Control System . . . . . . . . . . . . . . . . . . . . . . . . . 1-29
1-12 Electrical Installation - Temperature Bulb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-42
1-13 Overhead Console Circuit Breaker - Electrical Installation . . . . . . . . . . . . . . . . . 1-45
1-14 Instrument Panel - Electrical Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-46
1-15 Vertical Fin - Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-47
1-16 VNE Placard - Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-52
1-17 Tail Skid and Weight - Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-54
1-18 Return to Flight Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-58

FIGURES

Figure Page
Number Title Number

1-1 Tail Rotor Gearbox Output Shaft - Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

1-2 Tail Rotor Pitch Change Mechanism - Installation . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
1-3 Tail Rotor Hub and Blade Assembly - Installation . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
1-4 Directional Control System - Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-20
1-5 Airframe Structure - Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-25
1-6 Support and Damper Assembly - Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-28
1-7 Tail Rotor - Electrical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-34
1-8 Tail Rotor (With Blind Encoder Installed) - Wiring Diagram . . . . . . . . . . . . . . . . . . 1-37/1-38
1-9 Tail Rotor (With Encoding Altimeter Installed) - Wiring Diagram . . . . . . . . . . . . . . 1-39/1-40
1-10 Center Console - Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-41
1-11 Temperature Bulb - Electrical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-43
1-12 Electrical Installation - Overhead Console Circuit Breaker . . . . . . . . . . . . . . . . . . . 1-45
1-13 Instrument Panel - Electrical Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-46
1-14 Vertical Fin - Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-49
1-15 VNE Placard - Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-53
1-16 Tail Skid Assembly and Weights - Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-55
1-17 Tail Skid - Painting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-57

08 DEC 2004 1-1/1-2

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 BHT-206-SI-2054

INSTALLATION PROCEDURES

1-1. GENERAL INFORMATION

MATERIALS REQUIRED
BEFORE USING S O LV E N T S ,
Refer to BHT-ALL-SPM for specifications and source.
EXTINGUISH ALL FLAME AND PILOT
NUMBER NOMENCLATURE LIGHTS. KEEP PRODUCT AND ITS
VAPORS AWAY FROM HEAT, SPARKS,
C-100 Chemical Film Material A N D F L A M E . AV O I D U S I N G S PA R K
PRODUCING ELECTRICAL EQUIPMENT
C-101 Corrosion Preventive SUCH AS SWITCHES, APPLIANCES,
Compound, Grade 1 ETC. DURING APPLICATION AND UNTIL
C-104 Corrosion Preventive VA P O R S ARE GONE. AV O I D
Compound, Grade 2 PROLONGED BREATHING OF VAPORS
AND REPEATED CONTACT WITH SKIN.
C-204 Epoxy Polyamide Primer

C-309 Solvent (M.E.K.) 4. Following any drilling or cutting, remove burrs

and metal particles and wipe area with solvent M.E.K.
C-317 Adhesive (C-309). For aluminum, brush with chemical film
material (C-100). Follow application with a thin coat of
epoxy polyamide primer (C-204) to bare metal.

5. When installing ground wires, or components

requiring ground, clean structure surface to bare metal
to provide good electrical bond. Apply one coat of
ALL OPENINGS AND PORTS IN epoxy polyamide primer (C-204) over bond joint after
COMPONENTS, HOSES AND/OR TUBES completion.
DISCONNECTED OR R EMOVED TO
FACILITATE MODIFICATION SHALL BE 6. Apply corrosion preventive compound, Grade 2
CAPPED, PLUGGED, OR OTHERWISE (C-104), on all exposed bolt shanks prior to kit
SEALED TO PREVENT CONTAMINATION installation. After installation and torquing, coat bolt
DURING MODIFICATION. heads, nuts, washers and all external exposed threads
with corrosion preventive compound, Grade 1 (C-101).
1. Tag all parts, including attaching hardware
(unless otherwise noted), removed to gain access to 7. When installing this kit, exercise care to prevent
work areas. Protect parts from damage until damage to adjacent structure and equipment.
reinstalled.
8. Do not tie or clamp wire bundles until all kit wiring
has been routed and connected.
2. Consumable materials may or may not be
supplied with kit, depending on customers
requirements for consumable items at the time kit was 9. Perform continuity check on all wiring newly
ordered. To inform maintenance personnel of installed or disturbed during this modification.
consumables required, a MATERIALS REQUIRED
statement is provided at the beginning of each 10. Unless otherwise noted all hose clamps should
paragraph, as required. Refer to BHT-ALL-SPM for be installed to provide optimum clearance between
information on consumable materials (C-XXX). hoses and structure.

3. Refer to BHT-ELEC-SPM for electrical installation 11. Some parts of these kits may be delivered
procedures. pre-assembled.

08 DEC 2004 1-3

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

12. Allow 24 hours curing time (room temperature) b. Kit -111 introduces slotted support (stop) and
for adhesive (C-317). aluminum alloy bearing sleeves.

a. Accelerate curing using suitable heat source. c. Kit -113 introduces weighed tail skid.
Cure 60 to 90 minutes at 170 to 190 °F (77 to 88 °C).
d. Kit -117 introduces T/R modification -109 (427
yoke cap to increase clamp up).
13. Instructions are the same for all kit part numbers
except where noted.
1-2. PREPARATION
14. Description of kits as follows: 1. Ground helicopter for safe ground maintenance.

a. Kit -101 is the basic kit. 2. Disconnect battery.

1-4 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

1-3. TAIL ROTOR HUB AND BLADE 3. Remove existing output shaft (5) from tail rotor
ASSEMBLY AND TAIL ROTOR GEARBOX - gearbox (2) in accordance with BHT-206L series
MODIFICATION CR&O manual. Retain hardware.

1-4. TAIL ROTOR HUB AND BLADE ASSEMBLY 4. Discard the output shaft duplex bearing after
- REMOVAL removal.

5. Remove spiral bevel gear (4) from existing output

NOTE shaft (5). Retain hardware.
Protect parts from damage and
contamination until reinstalled. 1-6. TAIL ROTOR GEARBOX OUTPUT SHAFT -
INSTALLATION
1. Tag and identify all parts removed for purposes of
reassembly or proper disposition. MATERIALS REQUIRED

2. Remove existing tail rotor hub and blade from Refer to BHT-ALL-SPM for specifications and source.
helicopter. Refer to BHT-206L-4 Maintenance Manual.
NUMBER NOMENCLATURE
1-5. TAIL ROTOR GEARBOX - REMOVAL C-030 Lubricating Oil

C-317 Adhesive
1. Remove existing tail rotor gearbox (2, Figure 1-1)
from helicopter. Refer to BHT-206L-4 Maintenance C-328 Sealing Compound
Manual.
C-405 Lockwire
2. Disassemble pitch change mechanism from tail
rotor gearbox in accordance with BHT-206L series SPECIAL TOOLS REQUIRED
CR&O manual. Retain hardware for reuse (Refer to
Figure 1-2). NUMBER NOMENCLATURE

T101510 Holding Tool

NOTE
T101511 Spline Wrench
Disassemble tail rotor gearbox only to the
extent necessary to accomplish
modifications required. 1. Modify tail rotor gearbox (2, Figure 1-1) as
follows:

NOTE a. Clamp T101511 spline wrench in shop vise

The intent of this Service Instruction should with 32 spline teeth opening exposed and insert output
be accomplished prior to the scheduled shaft (5).
replacement of the duplex bearing.
b. Assemble spiral bevel gear (4) to new output
shaft (5) as follows:

(1) Apply a film of lubricating oil (C-030) to

spiral bevel gear (4). Heat spiral bevel gear (4) with
THE STRESS INDUCED IN THE DUPLEX heat lamp.
BEARING DURING REMOVAL OF THE
OUTPUT SHAFT (5, FIGURE 1-1) CAN (2) Apply a film of lubricating oil (C-030) to
CAUSE DAMAGE TO THE DUPLEX output shaft (5). Position spiral bevel gear (4) onto
BEARING. output shaft (5). Ensure bolt holes align.

08 DEC 2004 1-5

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

e. Measure backlash in accordance with

BHT-206L series CR&O manual.

f. Apply bead of sealant (C-328) to outer

DO NOT TORQUE BOLTS (3) UNTIL diameter of mating surface area of tail rotor
SPIRAL BEVEL GEAR HAS RETURNED
gearbox (2) and cap assembly (9).
TO AMBIENT TEMPERATURE.

(3) Install ten existing bolts (3) 1. Ensure 2. Remove existing identification plate from case
spiral bevel gear (4) is square and flush to flange on assembly.
output shaft (5).

(4) Secure bolts (3) in pairs with lockwire

(C-405).

c. Apply a film of lubricating oil (C-030) to new

wear sleeve (13) and to output shaft (5). Apply heat TO PREVENT DAMAGE TO TAIL ROTOR
lamp to wear sleeve until heated, then install wear GEARBOX CASE, MARKING SHALL BE
sleeve onto output shaft with chamfer toward splined ACCOMPLISHED PRIOR TO BONDING
end. Press wear sleeve onto output shaft until firmly IDENTIFICATION PLATE IN PLACE.
seated.

d. Install spiral bevel gear (4) and output 3. Mark new identification plate (1) with the
shaft (5) into tail rotor gearbox (2). Install nut (15) 2
assembly part number (206-040-402-103).
and cotter pin (16) and reassemble tail rotor gearbox
with new packing (8) in accordance with BHT-206L 4. Transfer the existing part serial number to new
series CR&O manual.
identification plate and add the suffix M. Stamp with
the appropriate inspection stamp or stamps, in blocks
NOTE provided.
After installation of new output shaft use
T101510 Holding Tool to secure tail rotor 5. Bond identification plate in place using adhesive
output shaft for backlash check. (C-317).

1-6 08 DEC 2004

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 BHT-206-SI-2054

Figure 1-1. Tail Rotor Gearbox Output Shaft - Installation (Sheet 1 of 2)

08 DEC 2004 1-7

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

Figure 1-1. Tail Rotor Gearbox Output Shaft — Installation (Sheet 2 of 2)

1-8 Rev. 1 16 NOV 2009 ECCN EAR99

BUY BELL PARTS, BUY BELL VALUE
 BHT-206-SI-2054

1-7. INSTALLATION - TAIL ROTOR GEARBOX 3. Connect driveshaft segment and slip adapter in
accordance with BHT-206L4 Maintenance manual.
1. Perform vertical fin modification prior to
installation of tail rotor gearbox. Refer to Paragraph 1- 4. Service tail rotor gearbox in accordance with
15. BHT-206L4 Maintenance manual.

2. Install tail rotor gearbox on tailboom using

existing nuts (12, Figure 1-2). Refer to BHT-206L4
Maintenance manual.

08 DEC 2004 1-9

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

Figure 1-2. Tail Rotor Pitch Change Mechanism - Installation (Sheet 1 of 2)

1-10 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

1. O-ring (2-38N141-7)
2. Nut (MS21042L4) 3 Reqd
Washer (NAS1197-416) 3 Reqd
3. Housing Assembly (Ref)
4. Boot (406-312-106-101)
5. Lockwire (MS20995C32) 2 places (C-405)
6. Trunnion Assembly (Ref)
7. Cap Assembly (Ref)
8. Nut (MS14145L6)
Washer (AN960-616L)
Cotter Pin (MS24665-289)
9. Bearing (Ref)
10. Idler Assembly (406-012-127-101)
11. Rod Assembly (206-011-751-101)
12. Nut (Ref) 4 Places
Washer (Ref) 4 Places
13. Bolt (AN3H7A) 4 Reqd
Washer (AN960-10L) 4 Reqd
Lockwire (MS20995C32) (C-405)
14. Bolt (NAS6604D32)
Washer (AN960-416) 2 Reqd
Nut (MS14144L4)
Cotter Pin (MS24665-155)
15. Lever Assembly (206-011-741-101) 2 Reqd
16. Bolt (NAS6604D21)
Washer (AN960-416) 2 Reqd
Nut (MS14144L4)
Cotter Pin (MS24665-155)
17. Bolt (NAS6604D31)
Washer (AN960-416) 2 Reqd
Nut (MS14144L4)
Cotter Pin (MS24665-155)
18. Bushing (206-011-726-005)
19. Bolt (NAS6604D15)
Washer (AN960PD416) 2 Reqd
Nut (MS14144L4)
Cotter Pin (MS24665-155)

With boot removed purge bearings with grease (C-001) past

seals to ensure proper lubrication.

Apply an external bead of sealant (C-351) at joint between

gearbox assembly and housing assembly after installation.

60 TO 80 IN-LB
1 (6.78 TO 9.04 Nm)

45 TO 65 IN-LB
2 (5.08 TO 7.34 Nm)

100 TO 140 IN-LB

3 (11.30 TO 15.82 Nm)

25 TO 30 IN-LB
4 (2.83 TO 3.39 Nm)
NOTES

1 Non-adjustable end.

2 Ensure lockwire does not cross over top of bolt head. 206_SI_2054_0004_c01

Figure 1-2. Tail Rotor Pitch Change Mechanism Installation (Sheet 2 of 2)

ECCN EAR99 9 JUN 2011 Rev. 2 1-11

FOR BEST VALUE, BUY GENUINE BELL PARTS
BHT-206-SI-2054

1-8. TAIL ROTOR HUB AND BLADE ASSEMBLY MATERIALS REQUIRED (Cont)
— INSTALLATION
Refer to BHT-ALL-SPM for specifications and source.
MATERIALS REQUIRED
NUMBER NOMENCLATURE
Refer to BHT-ALL-SPM for specifications and source. C-104 Corrosion Preventive
Compound
NUMBER NOMENCLATURE
C-308 Sealant
C-405 Lockwire
C-405 Lockwire
C-561 Grease
C-561 Grease

WARNING
NOTE
Apply corrosion preventive compound
E N S U R E T H AT N O P E R S O N N E L (C-104) to all bolt shanks prior to
OPERATES TAIL ROTOR CONTROLS installation. Do not apply to threads.
FROM INSIDE OF HELICOPTER DURING
I N S TA L L AT I O N O F TA I L R O T O R . 1. Refer to the BHT-206L-SERIES-CR&O manual
PHYSICAL INJURY CAN OCCUR. and the following instructions to assemble tail rotor
pitch change mechanism:
1. Apply grease (C-561) to inboard splines only and
threads of gearbox shaft (1, Figure 1-3) and mating a. Carefully insert control tube assembly (2,
surfaces of spacer (3), hub and blade assembly (4), Figure 1-3) through gearbox shaft (1).
support (5), and nut (6).
b. Install new O-ring (1, Figure 1-2) to housing
2. Install spacer (3), hub and blade assembly (4), assembly (3).
support (5, with flange side toward trunnion), and
nut (6) T 1. c. Install housing assembly (3) to tail rotor
gearbox case. Insert control tube assembly (2, Figure
1-3) into housing assembly (3, Figure 1-2). Avoid
NOTE damaging seals in housing. Secure housing to
gearbox case with washers and nuts (2) T 1, three
Torque check nut (6) after a minimum of
places.
1 hour, but not to exceed 5 hours of
service (Table 2-10).
d. Apply an external bead of sealant (C-308) at
joint between gearbox assembly and housing
3. Secure nut (6) to support (5) with lockwire
assembly.
(C-405).
e. Purge bearings with grease (C-001) past
1-9. TAIL ROTOR PITCH CHANGE MECHANISM seals to ensure proper lubrication.
— INSTALLATION
f. Position boot (4, Figure 1-2) around flange of
MATERIALS REQUIRED housing assembly (3) and secure with two wraps of
lockwire (5) (C-405).
Refer to BHT-ALL-SPM for specifications and source.

NUMBER NOMENCLATURE NOTE

C-001 Grease Refer to the BHT-206L-SERIES-CR&O
manual for reinstallation procedures of
C-101 Corrosion Preventive existing retaining ring, seals and roller
Compound bearings.

1-12 Rev. 2 9 JUN 2011 ECCN EAR99

BUY BELL PARTS, BUY BELL VALUE
 BHT-206-SI-2054

g. Carefully install trunnion assembly (6, Figure inside boot (4) and off trunnion assembly (6) and
1-2) onto end of control tube assembly (2, Figure 1-3) housing assembly (3).
so as not to damage installed seal.
s. Position boot (4) around flange on trunnion
h. Loosely install washer and nut (8, Figure 1-2) assembly (6) and secure with two wraps of
on end of control tube assembly (2, Figure 1-3). lockwire (5).

i. Use a wrench to hold tube assembly (2) at the t. Lubricate splines of crosshead (21, Figure 1-
machined area, as shown in Figure 1-3, Detail A, 3) with grease (C-001).
tighten nut (8, Figure 1-2) T 2 on opposite end of
control tube assembly (2, Figure 1-3) plus friction drag u. Position crosshead (21) and seal (22) onto
of nut. Secure with cotter pin (8, Figure 1-2). gearbox shaft (1) far enough to expose the machined
area on tube assembly (2).
j. Trim end of cotter pin to ensure trimmed end
will not contact trunnion cap assembly (7) or v. Install plate (13), with recess in plate
bearing (9). If required, an additional thin steel washer positioned outboard on tube assembly (2),
may be used (within torque tolerance) to obtain washer (18), and nut (16). Use a wrench to hold tube
required clearance. assembly (2) at the machined area, as shown in
Detail A, and tighten nut (16) T 3. Secure with cotter
pin (17).
NOTE
Position trunnion cap assembly (7) with w. Move crosshead (21) outboard toward
lubrication fitting up. plate (13). Install washers (14) and bolts (15) T 2.
Secure with lockwire (C-405).
k. Install trunnion cap assembly (7) to trunnion
assembly (6) and secure with washers and bolts (13)
NOTE
T 4. Secure in pairs with lockwire (13).
Install bolt heads in direction of rotation.
l. Install lever assemblies (15) on spindles of
trunnion assembly (6). x. Install pitch link (23) to crosshead (21) with
bolt (11), washers (12), and nut (20) T 2. Secure with
m. Install idler assembly (10) to housing cotter pin (19).
assembly (3) with bushing (18) and bolt, washer, and
nut (17) T 1. Secure with cotter pin (17). y. Install nut (9) and retainer (10) into pitch horn.
Connect pitch link (23) to pitch horn with washer (8)
n. Insert idler assembly (10) between lever and bolt (7) T 2. Secure bolt to pitch horn with
assemblies (15), and install bolt, washers, and lockwire (C-405).
nut (14).
z. Repeat step y to connect opposite pitch link.
o. Install non-adjustable end of rod
assembly (11) with bolt, washer, and nut (19).
CAUTION
p. Insert adjustable end of rod assembly (11)
between levers, and install bolt, washers, and nut (16).
DO NOT ALLOW CORROSION
q. Tighten nuts (14, 16, and 19) T 1 and secure PREVENTIVE COMPOUND TO ENTER
with cotter pins (14, 16, and 19). If required, one METALLIC OR ELASTOMERIC
additional thin steel washer may be used under nuts to BEARINGS.
provide cotter pin alignment within torque tolerance.
2. After assembly, coat external areas that are
r. Thoroughly purge and lubricate assembly at exposed to the environment, including exposed
fittings with grease (C-001). Wipe excess grease from threads, with corrosion preventive compound (C-101).

ECCN EAR99 9 JUN 2011 Rev. 2 1-13

FOR BEST VALUE, BUY GENUINE BELL PARTS
BHT-206-SI-2054

SEE
DETAIL A

206_SI_2054_0005_c01
Figure 1-3. Tail Rotor Hub and Blade Assembly — Installation (Sheet 1 of 3)

1-14 Rev. 2 9 JUN 2011 ECCN EAR99

BUY BELL PARTS, BUY BELL VALUE
 BHT-206-SI-2054

DETAIL A

206_SI_2054_0077_c01
Figure 1-3. Tail Rotor Hub and Blade Assembly — Installation (Sheet 2 of 3)

ECCN EAR99 9 JUN 2011 Rev. 2 1-15

FOR BEST VALUE, BUY GENUINE BELL PARTS
BHT-206-SI-2054

1. Gearbox Shaft (Ref) 11. Bolt (NAS6604D14) 2 Reqd

2. Tube Assembly (406-012-118-101) 12. Washer (AN960-416) 4 Reqd
3. Spacer (406-012-110-101) 13. Plate (406-012-104-103) 1 Reqd
4. Hub and Blade Assembly 14. Washer (AN960-416) 2 Reqd
(206-011-749-105) (Kit -101) 15. Bolt (NAS6604H3) 2 Reqd
Hub and Blade Assembly Lockwire (MS20995C32) (C-405)
(206-011-749-109) (Kits -111 and -113) 16. Nut (MS14145L8)
Hub and Blade Assembly 17. Cotter Pin (MS24665-306)
(206-011-749-113) (Kit -117) 18. Washer (AN960-816)
5. Support (206-011-752-101) 19. Cotter Pin (MS24665-155) 2 Reqd
6. Nut (406-012-113-101) 20. Nut (MS14144L4) 2 Reqd
Lockwire (MS20995C32) (C-405) 21. Crosshead (407-012-105-101)
7. Bolt (NAS6604H22) 2 Reqd 22. Seal (406-312-102-101)
Lockwire (MS20995C32) (C-405) 23. Pitch Link (406-312-103-101) 2 Reqd
8. Washer (AN960-416L) 24. Pitch Horn Assembly (406-012-108-101) 2 Reqd
9. Nut (NAS577-4A) 2 Reqd 25. Counterweight Support (Ref)
10. Retainer (NAS578-4B) 2 Reqd 26. Weight Support (Ref)

Apply grease (C-561) to inboard splines only and

1 threads of gearbox shaft, and mating surfaces of spacer,
tail rotor hub and blade assembly, support, and nut.

Lubricate splines of crosshead with grease (C-001).

2
60 TO 80 IN-LB
1 (6.78 TO 9.04 Nm)

120 TO 140 IN-LB

2 (13.56 TO 15.82 Nm)

560 TO 580 IN-LB

3 (63.27 TO 65.53 Nm)

NOTES

1 Install bolt head in direction of rotation.

2 Retorque nut after a minimum of 1 hour, but do not exceed 5 hours of service.

3. As an alternate to grease (C-561), use lubricant (C-012).

4. Apply corrosion preventive compound (C-104) to the shank of the bolts.

NO OBJECT BEYOND THIS POINT 206_SI_2054_0006_c01

Figure 1-3. Tail Rotor Hub and Blade Assembly — Installation (Sheet 3 of 3)

1-16 Rev. 2 9 JUN 2011 ECCN EAR99

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 BHT-206-SI-2054

1-10. DIRECTIONAL CONTROL SYSTEM - a. Locate existing 2.38 inch (60.45 mm) diameter
MODIFICATION hole in existing frame/doubler (1, Figure 1-5) at
FS 204.92, WL 60.48.
MATERIALS REQUIRED
b. Cut existing hole to 3.17 inch (80.51 mm) X
Refer to BHT-ALL-SPM for specifications and source. 2.32 inch (58.92 mm) X 0.50 inch (12.70 mm) radius.

NUMBER NOMENCLATURE
c. Reference dimensions shown in views C-C
C-201 Zinc Chromate Primer and D-D. Cut existing stiffener (13) to facilitate
installation of doubler (5). Locate and remove twenty
C-309 Solvent (M.E.K.) six (MS20470AD4) rivets securing canted web (3) to
existing stiffeners.
C-317 Adhesive

1. Remove access door (206-032-328) from right d. Temporarily position doubler (5) in place.
side FS 217.84. Where rivets were removed in Step c., backdrill twenty
six 0.128 inch (3.25 mm) diameter holes through
2. Remove baggage compartment upper and aft existing stiffeners (9) and (13) and doubler (5). Cleco
covers to gain access to FS 204.92. doubler in place.

3. Locate FS 206.62. Remove bolt, nut, washer, and e. Layout and drill thirteen 0.143 to 0.146 inch
cotter pin (11, Figure 1-4) securing forward end of (3.63 to 3.70 mm) diameter holes through doubler (5)
control tube assembly (22) to walking beam (10). and canted web (3) for rivets (7).

4. Remove bolt, nut, washer, and cotter pin (6) f. With doubler clecoed in place, mark area to be
securing aft end of control tube assembly (7) to cutout of canted web (3). Use doubler as a template.
bellcrank (4). Refer to dimensions shown in views C-C and D-D.

5. Remove bolt, nut, washers, and cotter pin (5) g. Temporarily position splice angles (6,
securing bellcrank (4) to walking beam (10). views D-D and E-E) on existing stiffeners (13). Locate
and remove eight interfering rivets through existing
6. Locate FS 152.56. Remove bolt, nut, washers, stiffener (9) and canted web (3), view D-D.
and cotter pin (8) securing forward end of control tube
assembly (7) to existing walking beam (9). Retain h. Where rivets were removed in Step g.,
attaching hardware and remove control tube backdrill eight 0.128 inch (3.25 mm) diameter rivet
assembly (7). holes through splice angles (6), existing stiffeners (13)
and canted web (3). Cleco splice angles in place.
7. Remove bolt, nut, washers, and cotter pin (12)
securing walking beam (10) to support (1). Remove
i. Refer to dimensions in view E-E and
and discard walking beam (10) and attaching
section F-F, layout and drill eight equally spaced
hardware.
0.128 inch (3.25 mm) diameter holes for rivets (12)
through splice angles (6) and stiffeners (13).
8. Remove bolt, nut, washers, and cotter pin (23)
securing aft end of control tube assembly (22) to
existing bellcrank (20). j. Remove doubler (5) and splice angles (6).

9. Remove bolt, nut, washers, and cotter pin (30) k. Where area was marked in Step f., cutout
securing existing bellcrank (20) to tailboom structure. 4.13 inch (104.90 mm) X 2.32 inch (58.92 mm) X
Remove and discard bellcrank and attaching 0.50 inch (12.70 mm) radius, opening in canted
hardware. web (3), views C-C and D-D.

10. Perform structural modification at FS 204.92 as l. Remove burrs and metal particles and wipe
follows: area with MEK (C-309).

08 DEC 2004 1-17

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

m. Cleco doubler (5) and splice angles (6) in 14. Locate BS 182.504 and install support (18, Figure
place as follows: 1-4) as follows:

(1) Install twenty-two rivets (8) through a. Remove existing ground lug (28). Retain
doubler (5), canted web (3), and existing stiffeners (9). hardware.

(2) Install thirteen rivets (7) through doubler

(5) and canted web (3).

(3) Install four rivets (10) through doubler (5),

canted web (3), splice angles (6), and existing A MINIMUM OF TWO RIVETS MUST BE
stiffeners (13). PICKED UP FOR SUPPORT (18)
INSTALLATION.
(4) Install eight rivets (11) through canted
web (3), splice angles (6) and stiffeners (13). b. Remove two or three existing rivets (as
required) and locate support (18).
(5) Install eight rivets (12) through splice
angle (6) and stiffeners (13). c. Where rivets were removed, maintain 0.01 to
0.09 inch (0.25 to 2.29 mm) clearance using shim
11. Remove bottom lug of support (1, Figure 1-4). stock or suitable work aid between support (18) and
Refer to dimension in Figure 1-4, sheet 1. tailboom support (26) as shown in view E-E and match
drill two or three (as required) 0.188 inch (4.77 mm)
diameter holes through tailboom and support (18).
12. Remove material from support (1) using
Ream holes to 0.1895 to 0.1915 inch (4.81 to
dimensions shown in Figure 1-4, view B-B and
4.86 mm) diameter for fasteners (19).
section C-C. This will prevent walking beam from
contacting support (1) at extreme right pedal position,
with ratio change actuator either extended or
NOTE
retracted.
To maintain proper edge distance, ensure
13. Install bracket (2, Figure 1-5) on frame at that pilot hole clears radius of support (18).
FS 204.92 as follows:
d. Reference dimensions in Figure 1-4, sheets 3
a. Measure outboard 1.40 inches (35.36 mm) and 4, drill one 0.093 inch (2.36 mm) pilot hole to
from edge of stiffener and mark a vertical line on determine most optimum hole distance from inboard
existing frame (1). radiuses of support (18), then ream hole to 0.189 to
0.195 inch (4.80 to 4.95 mm) diameter for screw (17).
b. Measure down 2.20 inches (55.88 mm) from
top of existing frame (1) and mark a horizontal line. e. Fill existing ground screw hole with adhesive
(C-317). Relocate per dimensions in Figure 1-4,
view E-E. Drill one 0.189 to 0.195 inch (4.80 to
c. Apply double back tape or equivalent to 4.95 mm) diameter hole at new location for existing
bracket (2) and secure in place. Locate per ground lug (28), view E-E. Deburr hole. Install ground
dimensions in Step a. and Step b. wire.

d. From pilot holes in bracket (2), match drill four f. Locate one 0.189 to 0.195 inch (4.80 to
0.128 to 0.133 inch (3.25 to 3.37 mm) diameter holes 4.95 mm) diameter hole in support (18). Match drill
through bracket (2) and frame (1). one 0.189 to 0.195 inch (4.80 to 4.95 mm) diameter
hole through support (26).
e. Remove double back tape or equivalent and
deburr holes. g. Remove support (18). Deburr all holes,
remove metal particles and wipe area with MEK
f. Install four rivets (4). (C-309).

1-18 08 DEC 2004

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 BHT-206-SI-2054

18. Locate FS 206.62, attach bellcrank

NOTE assembly (10), with actuator (2) and bellcrank (4)
Ensure that items (17) and (19) are wet attached, to support (1) and airframe structure. Install
installed with unreduced zinc chromate bolt, two washers, and nut (12). Secure with cotter
primer (C-201). pin (12).

h. Install support (18). Secure in place with bolt, 19. Attach bellcrank (16) to support (18). Install bolt,
two washers, (with thin washer under nut), and two washers, and nut (29). Secure with cotter pin (29).
Position head of bolt down, refer to view E-E.
nut (17). Install screw, two washers, and nut (27).
Install two or three (as required) studs, washers, and
nuts (19) with washer under nut. 20. Attach link assembly (15) to bellcrank (16).
Measure gap between bearing and clevis. Shim to
0.003 inch (0.076 mm) maximum gap between
15. Attach idler assembly (20) to existing bearing and clevis. Install bolt, two washers, and
support (26). Install bolt, two washers, and nut (30). nut (24). Secure with cotter pin (24).
Secure with cotter pin (30). Position head of bolt down,
refer to section F-F.
21. Attach control rod assembly (14) to
bellcrank (16). Measure gap between bearing and
16. Attach aft end of existing control tube clevis. Shim to 0.003 inch (0.076 mm) maximum gap
assembly (22) to idler assembly (20). Attach link between bearing and clevis. Install bolt, two washers,
assembly (15) to idler assembly (20) with two and nut (21) 2. Secure with cotter pin (21).
washers (25) position between idler and link, refer to
view D-D. Measure gap between bearing and clevis 22. Attach forward end of control tube assembly (22)
(2 places). Shim to 0.003 inch (0.076 mm) maximum to bellcrank assembly (10). Measure gap between
gap between bearing and clevis. Install bolt, two bearing and clevis. Shim to 0.003 inch (0.076 mm)
washers, and nut (23). Secure with cotter pin (23). maximum gap between bearing and clevis. Install bolt,
two washers, and nut (11). Secure with cotter pin (11).
17. Prior to installation, build up bellcrank
assembly (10) as follows: 23. Install control tube assembly (7). Locate
FS 152.56, attach forward end of control tube to
existing walking beam (9). Install existing hardware.
a. Attach actuator assembly (2) to bellcrank
Secure with cotter pin (8).
assembly (10). Install washer and bolt (13) 1.
Torque bolt finger tight to 10 inch-pounds (1.13 N-m).
24. Attach aft end of control tube assembly (7) to
Secure with lockwire (13).
bellcrank (4). Measure gap between bearing and
clevis. Shim to 0.003 inch (0.076 mm) maximum gap
b. Attach bellcrank (4) to bellcrank between bearing and clevis. Install bolt, two washers,
assembly (10). Measure gap between bearing and and nut (6). Secure with cotter pin (6).
clevis. Shim to 0.003 inch (0.076 mm) maximum gap
between bearing and clevis. Install bolt, washers and 25. Locate FS 63.18, under copilot seat area.
nut (5). Refer to Figure 1-4, sheet 1 for orientation of Remove and discard upper weight (1, Figure 1-6),
washers. Secure with cotter pin (5). dissimilar tape, and attaching hardware.

c. Attach aft end of bellcrank (4) to actuator 26. Re-install lower weight (3) with bolts and
assembly (2). Measure gap between bearing and washers (2). Secure with lockwire (2).
clevis. Shim to 0.003 inch (0.076 mm) maximum gap
between bearing and clevis. Install bolt, two washers, 27. Rig tail rotor control system in accordance with
and nut (3). Secure with cotter pin (3). Chapter 2.

08 DEC 2004 1-19

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BHT-206-SI-2054

Figure 1-4. Directional Control System - Installation (Sheet 1 of 5)

1-20 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

Figure 1-4. Directional Control System — Installation (Sheet 2 of 5)

ECCN EAR99 9 JUN 2011 Rev. 2 1-21

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BHT-206-SI-2054

206_SI_2054_0009_c01
Figure 1-4. Directional Control System — Installation (Sheet 3 of 5)

1-22 Rev. 2 9 JUN 2011 ECCN EAR99

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 BHT-206-SI-2054

1. Support (206-033-325) (Ref) 17. Bolt (NAS6603-5)

2. Actuator Assembly (206-301-052-103) Washer (AN960JD10L)
3. Bolt (NAS6604D13) Washer (140-002-2) Under Nut
Washer (AN960JD416) 2 Reqd Nut (MS21042L3)
Nut (MS14144L4) 18. Support (206-001-825-101)
Shim (120-032-16-8) Bottom Floating Bushing (21-025B19)
Cotter Pin (MS24665-155) Top Fixed Bushing (22-006B16-15-16)
4. Bellcrank (206-001-821-101) 19. Stud (100-048-6-7) 3 Reqd
5. Bolt (NAS6604D20) Washer (AN960JD10L) 3 Reqd Under Nut
Washer (AN960JD416) Under Bolt Head Nut (MS21042L3) 3 Reqd
Washer (AN960JD416L) Under Nut 20. Bellcrank (206-001-763-001) Remove
Nut (MS14145L4) Idler Assembly (206-001-822-101) Add
Shim (120-032-16-8) 21. Bolt (NAS6604D15)
Cotter Pin (MS24665-155) Washer (AN960JD416) 2 Reqd
6. Bolt (NAS6605D13) Nut (MS14144L4)
Washer (AN960JD516) 2 Reqd Shim (120-032-16-8)
Nut (MS14144L5) Cotter Pin (MS24665-155)
Shim (120-032-16-10) 22. Tube Assembly (206-001-058) (Ref)
Cotter Pin (MS24665-155) 23. Bolt (NAS6604D21)
7. Tube Assembly (206-001-097-007) Remove Washer (AN960JD416)
Tube Assembly (206-001-097-101) Add Washer (AN960JD416L) Under Nut
8. Cotter Pin (MS24665-155) Nut (MS14144L4)
9. Walking Beam (206-001-735) (Ref) Shim (120-032-16-8)
10. Walking Beam (206-001-759-005) Remove Cotter Pin (MS24665-155)
Bellcrank Assembly (206-001-820-101) Add 24. Bolt (NAS6604D12)
11. Bolt (NAS6604D15) Washer (AN960JD416) 2 Reqd
Washer (AN960JD416) 2 Reqd Nut (MS14144L4)
Nut (MS14144L4) Shim (120-032-16-8)
Shim (120-032-16-8) Cotter Pin (MS24665-155)
Cotter Pin (MS24665-155) 25. Washer (AN960JD416) 2 Reqd
12. Bolt (NAS6606D38) 26. Support (206-033-426) (Ref)
Washer (AN960JD616L) 2 Reqd 27. Screw (MS27039-1-12)
Nut (MS14144L6) Washer (AN960JD10L) 2 Reqd
Cotter Pin (MS24665-302) Nut (MS21042L3)
13. Bolt (NAS6604H12) 28. Existing Ground Lug (Relocate)
Washer (AN960JD416) 29. Bolt (NAS6604D24)
Lockwire (MS20995C41) Washer (AN960JD416) 2 Reqd
14. Rod Assembly (206-011-751-101) Nut (MS14144L4)
15. Link Assembly (206-001-823-101) Cotter Pin (MS24665-155)
16. Bellcrank (206-001-824-101) 30. Bolt (NAS6604D23)
Washer (AN960JD416) 2 Reqd
Nut (MS14144L4)
Cotter Pin (MS24665-155)

206_SI_2054_0010_c01

Figure 1-4. Directional Control System — Installation (Sheet 4 of 5)

ECCN EAR99 9 JUN 2011 Rev. 2 1-23

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BHT-206-SI-2054

Fill existing hole with adhesive (C-317).

10 IN-LB
1 (1.13 Nm)

60 TO 80 IN-LB
2 (6.78 TO 9.04 Nm)

Install bolt (17) and studs (19) wet with

zinc chromate primer (C-201).

NOTES

1 Remove bottom lug of support (1) to dimension shown.

2 See figure 1-5 for airframe modifications.

3 Reuse existing hardware. Secure with cotter pin (8).

4 Remove rivets this location and locate support (18) as shown.

Match drill thru existing rivet holes and thru support (18),
3 places, 0.188 inch (4.77 mm) diameter.

5 Locate hole thru support (18). Drill one pilot hole 0.093 inch (2.36 mm)
for optimum hole placement, then ream to 0.189 to 0.195 inch
(4.80 to 4.95 mm) diameter hole thru support (18) and support (26).

6 Install bolt head down.

7 Relocate ground lug. Refer to Note 8 shown in two locations, View

Looking Down and View E-E.

8 Relocate existing ground lug to this location, into casting closure skin.

9 Measure gap between bearing and clevis. Shim to 0.003 inch (0.076 mm)
maximum gap between bearing and clevis.

206_SI_2054_0074_c01

Figure 1-4. Directional Control System — Installation (Sheet 5 of 5)

1-24 Rev. 2 9 JUN 2011 ECCN EAR99

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 BHT-206-SI-2054

Figure 1-5. Airframe Structure - Modification (Sheet 1 of 3)

08 DEC 2004 1-25

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

Figure 1-5. Airframe Structure - Modification (Sheet 2 of 3)

1-26 08 DEC 2004

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 BHT-206-SI-2054

Figure 1-5. Airframe Structure - Modification (Sheet 3 of 3)

08 DEC 2004 1-27

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BHT-206-SI-2054

Figure 1-6. Support and Damper Assembly - Modification

1-28 08 DEC 2004

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 BHT-206-SI-2054

1-11. ELECTRICAL INSTALLATION - console to actuator along upper right side of

DIRECTIONAL CONTROL SYSTEM passenger compartment.

MATERIALS REQUIRED 3. Locate 206-075-545 RPM sensor (6, Figure 1-7).

Refer to BHT-ALL-SPM for specifications and source. a. Measure forward 0.7 inch (17.78 mm) from
center of screw (5). Mark this location. Measure
NUMBER NOMENCLATURE forward 0.518 inch (13.16 mm) from previous mark.
Draw a line parallel to previous mark.
C-100 Chemical Film Material

C-311 Adhesive b. Measure inboard 0.6 inch (15.24 mm) from

LBL 3.06. Mark a line perpendicular to previous two
1. To facilitate installation of electrical wiring, lines.
disassemble instrument panel and center console as
follows: c. At locations marked, drill two 0.212 to
0.218 inch (5.38 to 5.54 mm) diameter holes through
a. Disconnect studs forward of glareshield that shelf.
attach console shroud to instrument panel.
d. Install rail assembly and modules (4) secure
with screw, washer, and nut (4).

e. Install decal (4) on adjacent structure such

that identification can be made after equipment is
installed.
ENSURE INSTRUMENT PANEL IS NOT
OVEREXTENDED CAUSING EXCESSIVE
T E N S IO N O N I NS T R UM E NT L I NES , NOTE
ELECTRICAL CABLES, HARNESSES,
ETC. The 206-706-051-103 Blind Encoder kit
must be installed prior to or concurrent with
this kit. The 206-706-007-101 Encoding
b. Remove screws that attach instrument panel
Altimeter may be installed in lieu of Blind
to console structure.
Encoder kit.

c. Tilt instrument panel aft to allow access to 4. Disconnect existing wiring at ATC Transponder
work area. (KT-76A or KT-70) and reterminate at 9TB1 terminal
block, modules (4).
d. Remove upper and lower, left and right panels
on center console to access terminal block work
areas. NOTE
Refer to Figure 1-8 for electrical installation
e. Remove windshield center post cover. of tail rotor authority with the Blind Encoder
kit installed. Refer to Figure 1-9 for
2. Remove custom interior panels to extent electrical installation of tail rotor authority
necessary to route actuator wiring from overhead with the Encoding Altimeter kit installed.

08 DEC 2004 1-29

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BHT-206-SI-2054

5. If Blind Encoder kit (206-706-051-101) is each wire and connect to 9TB1 terminal block,
installed, route the following existing wiring to 9TB1 modules (4) as follows:
terminal block. Install one M39029/22-191 contact on
end of each wire and terminate as follows:
Connect To
Wire No.
Pin No.
Connect To ALT-2B22 KC
Wire No.
Module Pin No.
ALT-3B22 KG
ALT-2A22 KA
ALT-4B22 KL
ALT-3A22 KE
ALT-5B22 KR
ALT-4A22 KJ
ALT-6B22 KY
ALT-5A22 KN
ALT-7B22 LC
ALT-6A22 KT
ALT-8B22 LG
ALT-7A22 LA
ALT-9B22 LL
ALT-8A22 LE
ALT-10B22 LR
ALT-9A22 LJ
ALT-11B22 LY
ALT-10A22 LN

6. If Encoding Altimeter kit (206-706-007-103) is NOTE

installed, route the following existing wiring to 9TB1 If 206-706-008 Transponder provisions are
terminal block. Install one M39029/22-191 contact on not installed, tie back and stow wires
end of each wire and terminate as follows: installed in Step 8.

8. Install 030-01107-0010 terminal on opposite end

Connect To of each wire and connect wiring to 3410TR1P1 plug as
Wire No.
Module Pin No. follows:
ALT-1A22 LA
ALT-2A22 KT Connect To
ALT-3A22 LE Wire No. 3410TR1P1 Module Pin
No.
ALT-4A22 KN
ALT-5A22 LT ALT-2B22 M

ALT-6A22 LN ALT-3B22 K

ALT-7A22 KJ ALT-4B22 J

ALT-8A22 KE ALT-5B22 E

ALT-9A22 LJ ALT-6B22 C

ALT-10A22 KA ALT-7B22 B
ALT-8B22 D
7. Route the following wires, part of 206-575-200- ALT-9B22 L
113 cable assembly, from 9TB1 terminal block ALT-10B22 H
modules (4, Figure 1-7) to ATC Transponder (KT-76A
or KT-70). Install M39029/22-191 contact on end of ALT-11B22 8

1-30 08 DEC 2004

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 BHT-206-SI-2054

9. Route the following wires, part of 206-575-200- 13. Route the following wires, part of 206-575-200-
113 cable assembly from 9TB1 terminal block, 113 cable assembly to center console. Refer to wiring
modules (4) to control panel assembly (3), plug diagram, Figure 1-8 or Figure 1-9. Install M39029/63-
9A1P1. Install M39029/22-191 contact on one end of 368 contacts on wires to build up 9A1P1 plug as
each wire and connect to 9TB1 terminal block as follows:
follows:

Connect To
Wire No.
Connect To Module Pin No.
Wire No.
9A1P1 Pin No.
C509A22 VIO 30
ALT-2C22 KD C509A22 VBLU 31
ALT-3C22 KH C511A22 32
ALT-4C22 KM C512A22 8
ALT-5C22 KS C513A22 7
ALT-6C22 KZ C514A22 20
ALT-7C22 LD C515A22 27
ALT-8C22 LH C516A22 22
ALT-9C22 LM
ALT-10C22 LS NOTE

10. Install M39029/63-368 contact on opposite end of The following procedures shall be followed
each wire and connect to plug 9A1P1, part of control when solder sleeves are required for
panel assembly (3), as follows: terminating wire shields.

14. Install solder sleeves as follows:

Connect To
Wire No.
Module Pin No. a. Strip outer insulation jacket and shield to
expose a maximum of 5 inch (127.0 mm) length of
ALT-2C22 19
insulated conductor. The exposed length of conductor
ALT-3C22 18 should be sufficient to accept insertion and removal
ALT-4C22 15 tools if applicable. Strip outer insulating jacket and
shield to expose a 3 to 4 inch (76.2 to 101.6 mm)
ALT-5C22 13
length of insulated conductor.
ALT-6C22 11
ALT-7C22 12 b. Strip outer jacket to expose 0.25 to 0.31 inch
(6.35 to 7.87 mm) bare shield.
ALT-8C22 14
ALT-9C22 16 c. Place M83519/2 shield termination over wire.
ALT-10C22 17 Center solder ring over bare shield, and apply heat
using heat gun. While heating, observe solder ring
11. Route wires C515A22, C514A22, and C512A22 through transparent sleeve. Continue to heat until
part of 206-575-200-113 cable assembly to 8TB3 solder ring changes from a dull red color to bright
terminal block. Install M39029/1-101 contacts on silver and flows toward the dams on either end of
C515A22 wire and connect to pin H4, C514A22 wire sleeve. Just prior to the bright flow, the solder ring may
and connect to pin J2, and C512A22 wire and connect collapse. Remove heat gun.
to pin J4.
d. If less than four shields are to be terminated,
12. Route C513A22 wire, part of 206-575-200-113 at a given termination point, each shield shall be
cable assembly to 8TB1 terminal block. Install terminated in a M83519/2 shield termination and
(M39029/1-101) contact on C513A22 wire and pigtails shall be “daisy-chained” from shield
connect to pin H3. termination to shield termination. The last shield

08 DEC 2004 1-31

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

termination shall be used to terminate the shields to a 20. Install M39029/56-348 contacts on wires to
connector pin. build up 9B1J1 receptacle as follows:

15. Install M83519/2-8 solder sleeves to wires

C509A22 VIO and C509A22 VBLU. Follow procedures Connect To
Wire No.
in Step 14. a. through d., to link shielded wiring Module Pin No.
together and terminate at plug 9A1P1, pin 24, with C500A22 1
M39029/63-368 contact. C501A22 2
C502A22 3
16. Install support installation (11, Figure 1-7) at view
C503A22 4
D-D as follows:
C504A22 5
C505A22 13
a. Using nut (11) as a guide, drill two 0.128 inch
(3.25 mm) diameter holes through bulkhead and C506A22 WHT 9
deburr holes. C506A22 BLU 10
C507A22 BLU 11
b. Install nut (11) and rivets (11). C507A22 WHT 12
C508A22N 8
c. Install clamp (12) using screw and
washer (11). 21. Install M83519/2-8 solder sleeves to wires
C507A22 WHT and C507A22 BLU. Install M83519/2-8
17. Install grommets (13) in place with adhesive solder sleeves to wires C506A22 WHT and C506A22
(C-311) using locations shown in views E-E and F-F. BLU.

18. Install electrical bond installation (14, view F-F) 22. Follow procedures in Step 14. a. through d., to
as follows: link shielded wiring and terminate at plug 9B1J1, pin 7,
with M39029/56-348 contact.
a. Drill one 0.193 to 0.198 inch (4.90 to 5.04 mm)
diameter hole using location in view E-E. Remove 23. Install M3519/2-7 solder sleeves to wires
primer around hole and apply chemical film material C500A22, C501A22, C502A22, and C503A22.
(C-100) for proper electrical bond.
24. Follow procedures in Step 14. a. through d., to
b. Temporarily install screw, washers, and link shielded wiring and terminate at plug 9B1J1, pin 6,
nut (14). with M39029/56-348 contact.

19. Route cable assembly (8) wires from center 25. Install MS25036-103 terminal to C508A22N wire
console along right side of fuselage between controller and route to local ground using electrical ground
and actuator as follows: install (14).

a. Remove tie wraps and route cable 26. Perform continuity check of cable assembly (8)
assembly (8) wires with existing wires. Install new tie upon completion of wiring harness installation.
wraps as required, supplied in kit.
27. Install 9B1J1 receptacle to bracket with retainer
b. Route cable assembly wires through and four screws and washers (10, Figure 1-7). Install
clamp (12, view D-D) and grommets (13, views E-E decal (10) adjacent to receptacle such that
and F-F). identification can be made after equipment is installed.

1-32 08 DEC 2004

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 BHT-206-SI-2054

28. Secure 206-575-200-113 cable assembly to 31. Reference dimensions in section A-A. Remove
existing clamp and bracket located right of actuator shaded area from frames (4) and (5).
assembly at FS 204.92 with bracket, clamp, screw,
washer and nut (7). Tie wrap closed loop in wire 32. Drill two forward screw holes in cover (3) to
bundle, forward of connector to induce bundle rigidity 0.250 inch (6.35 mm) diameter and install plug
for clearance in area of moving parts. Use buttons (3).
MS3367-7-9 tie wrap.
33. Reinstall cover (3) with hardware removed in
29. Remove two screws and washers (2) and Step 29.
cover (3) from center console.
34. Assemble 9A1P1 connector and install to control
30. Locate and remove cover (3, Figure 1-10) and panel assembly (3, Figure 1-7). Install control panel
attaching hardware. assembly into center console with four screws (3).

08 DEC 2004 1-33

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BHT-206-SI-2054

Figure 1-7. Tail Rotor - Electrical Installation (Sheet 1 of 3)

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 BHT-206-SI-2054

Figure 1-7. Tail Rotor - Electrical Installation (Sheet 2 of 3)

08 DEC 2004 1-35

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

Figure 1-7. Tail Rotor - Electrical Installation (Sheet 3 of 3)

1-36 08 DEC 2004

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 BHT-206-SI-2054

Figure 1-8. Tail Rotor (With Blind Encoder Installed) - Wiring Diagram

08 DEC 2004 1-37/1-38

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 BHT-206-SI-2054

Figure 1-9. Tail Rotor (With Encoding Altimeter Installed) - Wiring Diagram

08 DEC 2004 1-39/1-40

GENUINE BELL PARTS ARE YOUR BEST VALUE
 BHT-206-SI-2054

Figure 1-10. Center Console - Modification

08 DEC 2004 1-41

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

1-12. ELECTRICAL INSTALLATION - a. Measure back approximately 4.0 inches

TEMPERATURE BULB (101.60 mm) from end of twisted cable assembly (13,
Figure 1-11). Cut, slit and remove jacket to expose
braid.
MATERIALS REQUIRED

Refer to BHT-ALL-SPM for specifications and source. b. Cut and remove 3.0 inches (76.20 mm) of
exposed braid. Leave approximately 1.0 inch
NUMBER NOMENCLATURE (25.40 mm) of braid exposed for installation of solder
sleeve (10).
C-100 Chemical Film Material

C-317 Adhesive
c. Slide braided EMI shield (12), anti-abrasion
braid (11), sleeving (14) and shrink boot (16) over
1. Install temperature bulb (6, Figure 1-11) as twisted cable assembly (13).
follows:

d. Install solder sleeve (10) over exposed braid

a. Locate clamp securing engine instrument
of twisted cable assembly (13).
hardlines (2) at FS 55.00, outboard of BL 0.00.

e. Pull wires (18) through backshell (8).

b. Measure inboard 1.25 inches (31.75 mm) from
screw. Mark fuselage skin. Measure forward
2.50 inches (63.50 mm) from FS 55.00. Draw a line at f. Strip wires (18) and install contacts (18).
this point intersecting previous marked location. Install wire C509A22 VIO to pin A of connector (17).
Install wire C509A22 VBLU to pin B of connector (17).
c. Drill one 0.452 to 0.459 inch (11.48 to
11.65 mm) diameter hole through outer skin. g. Install backshell (8) to connector (17).
Remove slack in wires (18) through backshell (8).
d. Enlarge hole to 1.375 inch (34.92 mm)
diameter through inner skin and honeycomb core. h. Slide braided EMI shield (12) into position
over solder sleeve (10) and aft end of backshell (8).
Secure braided EMI shield (12) to backshell (8) with
e. Remove honeycomb core 0.2 inch (5.08 mm)
EMI band (9).
and fill with adhesive (5) (C-317).

i. Secure braided lead of solder sleeve (10) to

f. Remove paint from outer skin to diameter of
braided EMI shield (12) with two strips of meltable
doubler (7) and apply Chemical Film Material (C-100).
tape (15). Apply appropriate heat source to melt tape
and bond braid lead to braided EMI shield (12).
g. Bond doubler (7) to outer skin as shown in
view B-B, with adhesive (5) (C-317).
j. Position anti-abrasion braid (11) over installed
braided EMI shield (12). Position shrink boot (16) over
h. Install temperature bulb (6) through forward end of anti-abrasion braid (11) and aft end of
doubler (7). Secure with washers and nut (6). backshell (8). Position sleeving (14) over aft end of
anti-abrasion braid (11).
i. Install decal (4) adjacent to temperature
bulb (6). k. Apply appropriate heat source from heat gun
to shrink sleeving (14) and shrink boot (16).
2. Route twisted cable assembly (13) from control
panel assembly (3, Figure 1-7) to temperature bulb. 3. Install connector (17) with EMI termination
Perform EMI termination as follows: installed to temperature bulb (6).

1-42 08 DEC 2004

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 BHT-206-SI-2054

Figure 1-11. Temperature Bulb - Electrical Installation (Sheet 1 of 2)

08 DEC 2004 1-43

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BHT-206-SI-2054

Figure 1-11. Temperature Bulb - Electrical Installation (Sheet 2 of 2)

1-44 08 DEC 2004

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 BHT-206-SI-2054

1-13. OVERHEAD CONSOLE CIRCUIT BREAKER 3. Install 9CB2 circuit breaker (2).
- ELECTRICAL INSTALLATION
4. Install decals (1) and (3).

5. Route wire C516A22 from control panel

assembly (3, Figure 1-7) to 9CB2 circuit breaker (2,
Figure 1-12). Install MS25036-149 terminal on wire
ENSURE 9CB2 CIRCUIT BREAKER IS C516A22 and connect to 9CB2 circuit breaker (2).
CONNECTED TO 28 VDC BUS.
6. Install one MS25036-156 terminal on one end of
1. Locate position for 9CB2 circuit breaker (2, wire C510A12 and connect to 9CB2 circuit breaker (2).
Figure 1-12) in overhead console (6) as shown in Install one MS25036-156 terminal on other end of wire
view A-A. C510A12 and connect to 28 VDC BUS.
2. Remove existing plug button (2).

Figure 1-12. Electrical Installation - Overhead Console Circuit Breaker

08 DEC 2004 1-45

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

1-14. INSTRUMENT PANEL - ELECTRICAL 3. Install nomenclature filter (2).

MODIFICATION
4. Route wire C511A22 from control panel
1. Locate upper left side of instrument panel (1, assembly (3, Figure 1-7) to caution panel (3, Figure 1-
Figure 1-13). 13). Install one 100-2020S contact to end of wire and
connect to pin b of 4DS1P1 plug.
2. Remove nomenclature filter (2) from first upper
position of caution panel.

Figure 1-13. Instrument Panel - Electrical Modification

1-46 08 DEC 2004

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 BHT-206-SI-2054

1-15. VERTICAL FIN — MODIFICATION Ensure that doubler is centered in hole within 0.03
inch (0.76 mm) with center pilot hole in doubler
MATERIALS REQUIRED assembly (3), shown in Detail B, aligned with
centerline of hole between existing rivet holes.
Refer to BHT-ALL-SPM for specifications and source.
10. Using pilot hole in doubler assembly (3), drill one
NUMBER NOMENCLATURE hole 0.129 to 0.132 inch (3.27 to 3.35 mm) in diameter
for rivet (2), through doubler assembly (3) and inboard
C-317 Adhesive skin of vertical fin (7) (Detail B). Countersink hole
C-392 Sealant 100°.

1. Remove vertical fin (7, Figure 1-14) in 11. Using hole finder or equivalent match, drill two
accordance with BHT-206L4-MM-5. rivet holes 0.143 to 0.146 inch (3.63 to 3.71 mm) in
diameter, through doubler assembly (3), picking up
2. Position vertical fin (7) on bench. existing rivet holes where rivets were removed
in step 4.
3. Remove existing vertical fin identification tag. Do
not discard tag at this time. Install work aid (8) on 12. Using pilot holes in doubler assembly (3), drill 17
vertical fin (7). Mark existing former where work aid (8) holes for rivets (1) 0.129 to 0.132 inch (3.27 to
intersects. Remove work aid and position support 3.35 mm) in diameter through doubler assembly (3)
assembly (4) where former was marked. Verify and inboard skin of vertical fin (7) (Detail B).
clearance where support assembly is to be installed
prior to cutting former. 13. Remove doubler and deburr holes in doubler
assembly (3) and vertical fin (7).
4. Remove eight rivets (5) securing fairing support
206-020-113-093 to vertical fin (7). 14. Temporarily cleco doubler in place. Mark area
where bonded identification tags interfere with
installation of doubler assembly (3). Remove doubler.
5. Cut and remove section of fairing support
206-020-113-093 where lines were drawn in step 3.
15. Remove interfering portion of bonded
identification tags from under doubler assembly (3).
6. Locate and remove one nutplate and attaching
rivets from existing fairing support 206-020-113-093.
16. Position support assembly (4) in place and
Discard nutplate.
temporarily secure to existing fairing support
206-020-113-093.
7. Install work aid (8) and using center alignment
hole mark fin.
17. Locate four existing rivet holes in fairing support
206-020-113-093 and two holes in doubler (3). Using
NOTE hole finder or equivalent, match drill six holes 0.143 to
0.146 inch (3.63 to 3.71 mm) in diameter through
Prior to cutting 2.75 inch (69.85 mm) hole in support assembly (4).
vertical fin, mark reference lines on doubler
assembly (3) and vertical fin outside of area 18. Maintaining edge distance from picked-up rivet
where doubler will fit in order to accurately holes, lay out and drill four rivet holes 0.129 to
locate doubler in the center of hole. 0.132 inch (3.27 to 3.35 mm) in diameter through
support assembly (4) and inboard skin of vertical fin
8. Using alignment hole marked on fin, measure (7). Refer to general locations in Detail D for rivet
and cut one hole 2.75 inch (69.85 mm) in diameter spacing.
through skin to depth of 0.34 inch (8.63 mm) in
honeycomb core. 19. Refer to dimensions in View C-C and Detail D,
and maintaining edge distance, lay out and drill five
9. Position doubler assembly (3) in place on vertical holes 0.128 to 0.133 inch (3.25 to 3.38 mm) in
fin. If necessary, trim radius of 2.75 inch (69.85 mm) diameter through former splice (4) and fairing support
hole to achieve a flush fit of doubler assembly (3). 206-020-113-093.

ECCN EAR99 9 JUN 2011 Rev. 2 1-47

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BHT-206-SI-2054

20. Locate existing hole for nutplate (10) in fairing 26. Temporarily secure support assembly (4) to
support 206-020-113-093. Match drill one hole 0.228 vertical fin (7).
to 0.233 inch (5.79 to 5.92 mm) in diameter through
support assembly (4). Pick up existing 0.098 inch 27. Install six rivets (6) and four rivets (13)
(2.49 mm) rivet attach holes, and match drill through through support assembly (4), fairing support
support assembly (4). Countersink 100°. 206-020-113-093, and vertical fin (7).

28. Install five rivets (12) through support

NOTE assembly (4) and fairing support 206-020-113-093.
Former can be trimmed up to 0.18 inch
(4.57 mm) to match indention in doubler 29. Install nutplate (10) to support assembly (4).
assembly (3) per locations shown in Secure with two rivets (11).
Detail D.
30. Apply a bead of sealant (C-392) to outer
21. Remove support assembly (4) and deburr holes. perimeter of support assembly (4).

22. Fill core/cavity of cutout in vertical fin (7) with 31. Refinish modified area to match existing paint
adhesive (C-317). If applicable, locate two rivet holes finish.
0.125 inch (3.17 mm) in diameter, one forward and
one aft of BS 179.48 at fin. Fill open holes in vertical 32. Add ’MOD PER SI-2054’ to new identification
fin with adhesive (C-317). plate as shown in Detail D.

23. Remove peel ply from doubler assembly (3) and 33. Transfer existing vertical fin part number and
apply adhesive (C-317) to faying surface prior to serial number to new identification plate (14) and
bonding. install as shown in Detail D.

24. Install one rivet (2) and 17 rivets (1). 34. Install a strip of anti-chafing tape (9) to support
assembly (4) where fairing interfaces.
25. Apply a bead of sealant (C-392) around perimeter
of doubler assembly (3) and mating surface of vertical 35. Install vertical fin (7) to tailboom in accordance
fin (7). with BHT-206L-4-MM-5.

1-48 Rev. 2 9 JUN 2011 ECCN EAR99

BUY BELL PARTS, BUY BELL VALUE
 BHT-206-SI-2054

Figure 1-14. Vertical Fin — Modification (Sheet 1 of 3)

ECCN EAR99 9 JUN 2011 Rev. 2 1-49

FOR BEST VALUE, BUY GENUINE BELL PARTS
BHT-206-SI-2054

10

206_SI_2054_0026_c01
Figure 1-14. Vertical Fin — Modification (Sheet 2 of 3)

1-50 Rev. 2 9 JUN 2011 ECCN EAR99

BUY BELL PARTS, BUY BELL VALUE
 BHT-206-SI-2054

1. Rivet (M7885/2-4-02) 17 Reqd

2. Rivet (M7885/3-4-02)
3. Doubler Assembly (206-023-133-101)
4. Support Assembly (206-530-123-107)
5. Rivet (Ref)
6. Rivet (M7885/6-4-03) 6 Reqd
7. Vertical Fin (Ref)
8. Work Aid (206-230-100-101)
9. Anti-Chafing Tape (C-460)
10. Nutplate (MS21059L3)
11. Rivet (MS20426AD3-4) 2 Reqd
12. Rivet (NAS1097AD4-4) 5 Reqd
13. Rivet (M7885/2-4-03) 4 Reqd
14. Identification Plate (100-088-1)

Apply adhesive (C-317).

Apply sealant (C-392) to edges of doubler assembly (3)

and support assembly (4).

NOTES

1 Remove rivet (5) two places and plug two 0.125 inch (3.175 mm) diameter holes in vertical fin (7).

2 Drill one 0.129 to 0.132 inch (3.27 to 3.35 mm) diameter hole for rivet (2), through doubler assembly (3)
and inboard skin of vertical fin (7). Countersink 100°.

3 Remove eight rivets (5) to facilitate removal of fairing support (206-020-113-093).

Match drill, with hole finder or equivalent, six 0.143 to 0.146 inch (3.63 to 3.71 mm)
diameter holes through support assembly (4) for rivets (6).

4 Cut 2.75 inch (69.85 mm) diameter hole through skin to depth of 0.34 inch (8.63 mm)
in honeycomb core.

5 Install a strip of anti-chafing tape (9) to support assembly (4) where fairing interfaces.

6 Using predrilled holes in doubler, along with existing holes in fin, mark and drill
additional rivet holes maintaining minimum edge distance to uniformly space rivet
holes in doubler (use additional flush rivets under support assembly if necessary), 22 places.

7 Locate and remove one nutplate (10) and attaching rivets. Discard nutplate.
Match drill one 0.228 to 0.233 inch (5.79 to 5.92 mm) diameter hole through support assembly (4).
Pick up existing 0.098 inch (2.49 mm) rivet attach holes, and match drill through support assembly (4).
Countersink 100°.

8 Layout and drill four 0.143 to 0.146 inch (3.63 to 3.71 mm) diameter rivet holes through support assembly (4)
and inboard skin of vertical fin (7). Holes must be evenly spaced between existing rivet holes.

9 Remove existing vertical fin identification tags. Transfer part number and serial number to
new identification plate (14) and locate as shown.

10 Add 'MOD PER SI-2054' to new identification plate. This will identify vertical fin assembly.

206_SI_2054_0027_c01

Figure 1-14. Vertical Fin — Modification (Sheet 3 of 3)

ECCN EAR99 9 JUN 2011 Rev. 2 1-51

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BHT-206-SI-2054

1-16. VNE PLACARD — INSTALLATION 3. Remove four existing screws securing existing
VNE placard to windshield trim panel (1). Discard
1. Remove four screws (2, Figure 1-15) securing placard and screws.
windshield trim panel (1) to center post.
4. Install decal (4) to plate (3). Secure to trim panel
2. Remove cap, and stow wires L157A22 and with four existing screws (5).
L158A22N.
5. Reinstall windshield trim panel (1) to center post
with four existing screws (2).

1-52 Rev. 2 9 JUN 2011 ECCN EAR99

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 BHT-206-SI-2054

Figure 1-15. VNE Placard - Installation

08 DEC 2004 1-53

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

1-17. TAIL SKID AND WEIGHT - 6. Install weights (7) and (8) on tail skid (3).
INSTALLATION
7. Apply sealant (C-392) on bolts (9) and attach
MATERIALS REQUIRED weights (7 and 8) to tail skid (3) with bolts (9),
washers (6) and nuts (5) 1.
Refer to BHT-ALL-SPM for specifications and source.

NUMBER NOMENCLATURE 8. Apply sealant (C-392) on two ends of weights (8).

C-245 Polyurethane Coating

(Red Paint) NOTE
C-246 Epoxy Polyamide Primer Use MIL-C-85285, Type 1, color 11136
(White Paint) (C-245) for red paint and MIL-C-85285,
Type 1, color 17875 (C-246) for white paint.
C-308 Adhesive Sealant

C-392 Sealant 9. Paint red and white stripes, alternating every

4 inches (101.60 mm), on tail skid (3) and weights (7)
1. Remove tail skid (3, Figure 1-16) from vertical and (8) as shown in Figure 1-17.
fin (1).
10. Install decal 31-053-18CFHP on top of weight
2. Mark location of new holes in tail skid.
assembly (8, Figure 1-16) and apply a layer of clear
paint (C-245) on decal.
3. Drill two holes of 0.176 inch (4.47 mm) diameter
to align with weights (7 and 8) (see Detail B).
11. Apply sealant (C-308) to tail skid area of
4. Apply a layer of sealant (C-392) on mating mount (4) on the vertical fin (1).
surfaces of weight (8) and tail skid (3).
12. Put tail skid (3) into mount (4) on vertical fin (1)
5. Apply sealant (C-392) on the faying surfaces of and install bolt (10), washers (11) and nut (12) 2.
weights (7) and (8). Safety with cotter pin (13).

1-54 08 DEC 2004

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 BHT-206-SI-2054

Figure 1-16. Tail Skid Assembly and Weights - Installation (Sheet 1 of 2)

08 DEC 2004 1-55

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

Figure 1-16. Tail Skid Assembly and Weights - Installation (Sheet 2 of 2)

1-56 08 DEC 2004

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 BHT-206-SI-2054

Figure 1-17. Tail Skid - Painting

08 DEC 2004 1-57

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

1-18. RETURN TO FLIGHT CONFIGURATION e. Refuel helicopter.

1. Return helicopter to flight configuration as f. Connect battery.

follows:
2. Perform the following procedures prior to ground
a. Ensure all hardware is secured and properly run-up and test flight. Refer to Chapter 2, Operation
safetied. and Maintenance.

b. Check all new wiring, connections and clamps a. Perform rigging procedures.
for security and absence of chafing hazards.
b. Perform pedal friction adjustment.
c. Install all access doors/panels, seats,
upholstery, soundproofing, etc., removed to gain c. Perform functional test of TRACU control
access to work area. panel.

d. Adjust ballast for proper weight and balance

per Chapter 2.

1-58 08 DEC 2004

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 BHT-206-SI-2054

CHAPTER 2 — OPERATION AND MAINTENANCE

TABLE OF CONTENTS

Paragraph Page
Number Title Number

OPERATION AND MAINTENANCE

2-1 Operation Procedures......................................................................................... 2-7

2-2 Maintenance Procedures .................................................................................... 2-7
2-3 Tail Rotor Hub and Blade — Assembly ......................................................... 2-7
2-4 Tail Rotor Hub and Blade — Static Balance.................................................. 2-10
2-5 Static Balance With Tool Kit A — Setup ................................................ 2-10
2-6 Static Balance With Tool Kit B — Setup ................................................ 2-13
2-7 Spanwise Static Balance — Adjustment ................................................ 2-18
2-8 Chordwise Static Balance — Adjustment .............................................. 2-18
2-9 Directional Control System — Rigging .......................................................... 2-19
2-10 Pedal Friction Adjustments ................................................................................. 2-26
2-11 Counterweight Adjustment............................................................................. 2-26
2-12 Dynamic Balance ................................................................................................ 2-27
2-13 RADS-AT Hardware and Software Requirements ......................................... 2-27
2-14 RADS-AT Hardware............................................................................... 2-27
2-15 RADS-AT Software ................................................................................ 2-28
2-16 Sources and Limits for Vibration.................................................................... 2-28
2-17 Tail Rotor Balancing ...................................................................................... 2-29
2-18 Purpose.................................................................................................. 2-29
2-19 Balancing the High Altitude Tail Rotor ................................................... 2-29
2-20 RADS-AT — Installation................................................................. 2-29
2-21 Obtaining Tail Rotor Balance Data................................................. 2-31
2-22 Adjusting Tail Rotor Balance .......................................................... 2-35
2-23 Balance Criteria for the High Attitude Tail Rotor ............................ 2-37
2-24 Tasks to Be Conducted After Balancing the Tail Rotor.......................... 2-40
2-25 Tail Rotor Authority Control Unit (TRACU) — Functional Test Procedures ........ 2-40
2-26 Setup ............................................................................................................. 2-40
2-27 Lamp and Self-test......................................................................................... 2-40
2-28 Altimeter Data Test ........................................................................................ 2-41
2-29 Rigging Mode Test......................................................................................... 2-41
2-30 Tail Rotor Authority Control Unit (TRACU) Control Panel — Troubleshooting ... 2-42
2-31 Tail Rotor Hub and Blade Assembly ................................................................... 2-44
2-32 Tail Rotor Hub and Blade Assembly — Description ...................................... 2-44
2-33 Tail Rotor Hub and Blade Assembly — Cleaning .......................................... 2-44
2-34 Tail Rotor Hub and Blade Assembly — Inspection........................................ 2-46
2-35 Condition and Security — General Inspection ....................................... 2-46
2-36 Tail Rotor Hub and Blade Assembly — Removal .......................................... 2-46
2-37 Tail Rotor Hub and Blade Assembly — Installation ....................................... 2-47
2-38 Tail Rotor Hub and Blade Assembly Attaching Components.............................. 2-48
2-39 Mast Nut — Inspection .................................................................................. 2-48
2-40 Mast Nut — Repair ........................................................................................ 2-48
2-41 Flapping Stop — Inspection........................................................................... 2-48
2-42 Flapping Stop — Repair ................................................................................ 2-48
2-43 Tail Rotor Blade Assembly.................................................................................. 2-48
2-44 Tail Rotor Blade Assembly — Description..................................................... 2-48

ECCN EAR99 9 JUN 2011 Rev. 2 2-1

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BHT-206-SI-2054

TABLE OF CONTENTS (CONT)

Paragraph Page
Number Title Number

2-45 Tail Rotor Blade Assembly — Removal......................................................... 2-48

2-46 Tail Rotor Blade Assembly — Inspection ...................................................... 2-48A
2-46A Blade Leak Check.......................................................................................... 2-52
2-47 Tail Rotor Blade Assembly — Repair ............................................................ 2-52B
2-48 Surface Damage — Repair.................................................................... 2-52B
2-49 Edge Voids — Repair ............................................................................ 2-53
2-49A Blade Exterior Surface and Leading Edge Drain Hole — Repair........... 2-53
2-49B Blade Root End Cuff — Repair .............................................................. 2-54
2-50 Blade Bolt Retention Bushing — Replacement ..................................... 2-54
2-51 Damaged Skin with no Core Damage or Core Damage Limited to
1.0 Square Inch (645.2 mm²) — Repair................................................. 2-54
2-52 Damaged Skin and Core Exceeding 1.0 Square Inch (645.2 mm²)
— Repair................................................................................................ 2-56
2-53 Blade Root End Sealant — Replacement.............................................. 2-56
2-54 Repaired Areas of Blade — Refinishing ................................................ 2-56
2-54A Tail Rotor Blade Assembly — Installation...................................................... 2-58
2-55 Tail Rotor Blade Assembly Components ............................................................ 2-59
2-56 Counterweight Support — Removal .............................................................. 2-59
2-57 Counterweight Support — Inspection ............................................................ 2-59
2-58 Counterweight Support — Repair.................................................................. 2-59
2-59 Counterweight Support — Installation ........................................................... 2-59
2-60 Pitch Horn — Removal .................................................................................. 2-61
2-61 Pitch Horn — Inspection ................................................................................ 2-61
2-62 Pitch Horn — Repair...................................................................................... 2-61
2-63 Pitch Horn — Installation ............................................................................... 2-61
2-64 Tail Rotor Hub Assembly .................................................................................... 2-63
2-65 Tail Rotor Hub Assembly — Description ....................................................... 2-63
2-66 Tail Rotor Hub Assembly — Disassembly ..................................................... 2-63
2-66A Tail Rotor Hub Assembly — Non Destructive Inspection .............................. 2-63
2-66B Tail Rotor Hub Assembly — Fluorescent Penetrant Inspection..................... 2-63
2-67 Tail Rotor Hub Assembly — Assembly.......................................................... 2-64
2-68 Tail Rotor Hub Assembly Components............................................................... 2-64
2-69 Weight Support — Removal .......................................................................... 2-64
2-70 Weight Support — Inspection ........................................................................ 2-64
2-71 Weight Support — Repair.............................................................................. 2-64
2-72 Weight Support — Installation ....................................................................... 2-64
2-73 Clamp Ring — Removal ................................................................................ 2-65
2-74 Clamp Ring — Inspection .............................................................................. 2-65
2-75 Clamp Ring — Repair.................................................................................... 2-65
2-76 Clamp Ring — Installation ............................................................................. 2-65
2-77 Yoke — Inspection......................................................................................... 2-65
2-78 Yoke — Repair .............................................................................................. 2-66
2-79 Yoke Pitch Change Bearings — Inspection................................................... 2-66
2-80 Pitch Change Bearings — Replacement ............................................................ 2-66
2-81 Pitch Change Bearings — Tools Description................................................. 2-66
2-82 Workaids and Tools ............................................................................... 2-66
2-83 Staking Tools ......................................................................................... 2-68
2-84 Pitch Change Bearings Axial — Play Check ................................................. 2-68

2-2 Rev. 2 9 JUN 2011 ECCN EAR99

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 BHT-206-SI-2054

TABLE OF CONTENTS (CONT)

Paragraph Page
Number Title Number

2-85 Pitch Change Bearings — Removal .............................................................. 2-68

2-86 Pitch Change Bearings — Installation ........................................................... 2-69
2-87 Required Shims Calculation................................................................... 2-69
2-88 Bearings Staking.................................................................................... 2-74
2-89 Bearing Proof Load Check After Staking ............................................... 2-80
2-90 Bearing Centering Check After Staking ................................................. 2-81
2-91 Pitch Change Bearing — Installation ..................................................... 2-82
2-92 Flapping Bearing — Removal........................................................................ 2-82
2-93 Flapping Bearing Splined Trunnion — Inspection ......................................... 2-82
2-94 Flapping Bearing Splined Trunnion — Repair ............................................... 2-82
2-95 Flapping Bearing Elastomer — Inspection .................................................... 2-82
2-96 Flapping Bearing — Installation..................................................................... 2-89
2-97 Tail Rotor Pitch Change Mechanism .................................................................. 2-89
2-98 Tail Rotor Pitch Control Tube ........................................................................ 2-89
2-99 Tail Rotor Pitch Control Tube — Removal ............................................. 2-89
2-100 Tail Rotor Pitch Control Tube — Inspection and Repair ........................ 2-92
2-101 Tail Rotor Control Tube — Installation................................................... 2-92
2-102 Pitch Link Assembly....................................................................................... 2-92
2-103 Pitch Link Assembly — Removal ........................................................... 2-92
2-104 Pitch Link Assembly — Inspection and Repair ...................................... 2-92
2-106 Driver Plate .................................................................................................... 2-93
2-107 Driver Plate — Removal ........................................................................ 2-93
2-108 Driver Plate — Inspection and Repair.................................................... 2-93
2-109 Driver Plate — Installation ..................................................................... 2-93
2-110 Crosshead ..................................................................................................... 2-93
2-111 Crosshead — Removal .......................................................................... 2-93
2-112 Crosshead — Inspection and Repair ..................................................... 2-94
2-113 Crosshead — Installation....................................................................... 2-94
2-114 Tail Rotor Gearbox.............................................................................................. 2-94
2-115 Tail Rotor Gearbox — Removal and Installation ........................................... 2-94
2-116 Tail Rotor Gearbox — Disassembly/Assembly .............................................. 2-94
2-117 Output Shaft — Inspection............................................................................. 2-94
2-118 Tail Rotor Gearbox — Backlash Check ......................................................... 2-94
2-119 Wear and Damage Limits ................................................................................... 2-94
2-120 Scheduled Inspection.......................................................................................... 2-122
2-121 100 Hours and Annual ................................................................................... 2-122
2-123 Special Inspections ............................................................................................. 2-125
2-124 Deleted .......................................................................................................... 2-125
2-125 3000 Hours of Component Operation............................................................ 2-126
2-126 Operation in a Corrosive Atmosphere ........................................................... 2-127
2-127 After Storage.................................................................................................. 2-128
2-128 Conditional Inspections....................................................................................... 2-129
2-129 After Hard Landing......................................................................................... 2-129
2-130 Sudden Stoppage/Acceleration ..................................................................... 2-130
2-131 After Main Rotor Overspeed 114% or Greater .............................................. 2-131
2-132 After Overtorque ............................................................................................ 2-132
2-133 After Lightning Strike ..................................................................................... 2-133
2-134 Component Overhaul Schedule.......................................................................... 2-134

ECCN EAR99 9 JUN 2011 Rev. 2 2-3

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BHT-206-SI-2054

TABLE OF CONTENTS (CONT)

Paragraph Page
Number Title Number

2-135 Tail Rotor Hub Assembly — Overhaul Inspection Sheet .................................... 2-135
2-136 Weight and Balance............................................................................................ 2-137

FIGURES

Figure Page
Number Title Number

2-1 Tail Rotor Hub and Blade — Assembly .............................................................. 2-8

2-2 Static Balance — Tool Kit A ............................................................................... 2-11
2-3 Static Balance — Tool Kit B, Spanwise and Chordwise Balance ....................... 2-15
2-4 Rigging — Directional Control System................................................................ 2-20
2-5 Schematic of RADS-AT Installation for Tail Rotor Balancing on the
Model 206L Series .............................................................................................. 2-30
2-6 Schematic of RADS-AT Installation for Tail Rotor Balancing.............................. 2-32
2-7 Proper CADU Main Menu Display for Conducting Tail Rotor Mode for the
Model 206L With the High Altitude Tail Rotor Kit................................................ 2-33
2-8 Balance Locations for High Altitude Tail Rotor ................................................... 2-38
2-9 Balancing Chart for 206L4 High Altitude T/R Showing Angles in Hours and
Degrees (for Use With RADS-AT) ...................................................................... 2-39
2-10 Tail Rotor Assembly — Description .................................................................... 2-45
2-10A Tail Rotor Blade Assembly — Removal/Installation............................................ 2-49
2-11 Blade Assembly (400-016-100) — Inspection and Repair.................................. 2-50
2-11A Blade Leak Check............................................................................................... 2-52A
2-12 Skin and Core — Damage Repair ...................................................................... 2-55
2-13 Blade Root End Sealant — Replacement........................................................... 2-57
2-14 Blade Paint Scheme — Description.................................................................... 2-58B
2-15 Counterweight Support — Removal and Installation .......................................... 2-60
2-16 Pitch Horn — Removal and Installation .............................................................. 2-62
2-17 Tail Rotor Hub Assembly and Weight Support — Disassembly/Assembly......... 2-64A
2-18 Workaids ............................................................................................................. 2-67
2-19 Bearing and Sleeve — Removal......................................................................... 2-72
2-20 Yoke and Bearing Marking for References ......................................................... 2-73
2-21 Measurements for Required Shims Calculation.................................................. 2-75
2-22 Bearing Staking................................................................................................... 2-77
2-23 Bearing Proof Load ............................................................................................. 2-78
2-24 Bearing Centering Check.................................................................................... 2-83
2-25 Workaid Item No. 1 and No. 2............................................................................. 2-84
2-26 Flapping Bearing — Removal ............................................................................. 2-85
2-27 Flapping Bearing Elastomer — Inspection and Repair ....................................... 2-86
2-28 Flapping Bearing Elastomer — Installation......................................................... 2-90
2-29 Tail Rotor Control Tube and Sleeve Vent ........................................................... 2-91
2-30 Output Shaft (206-040-949) — Damage Limits .................................................. 2-95
2-31 Output Shaft (206-040-949) — Wear Limits ....................................................... 2-97
2-32 Output Shaft (206-040-949) — Runout Limits .................................................... 2-98
2-33 Output Shaft (206-040-949) — Finish Requirements ......................................... 2-99
2-34 Yoke — Inspection and Repair ........................................................................... 2-100

2-4 Rev. 2 9 JUN 2011 ECCN EAR99

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 BHT-206-SI-2054

FIGURES (CONT)

Figure Page
Number Title Number

2-35 Crosshead (407-012-105) — Damage Limits ..................................................... 2-102

2-36 Support (206-011-752) — Damage Limits .......................................................... 2-103
2-37 Pitch Horn Assembly (406-012-108) — Damage Limits ..................................... 2-104
2-38 Rod Assembly (206-011-751) — Damage Limits ............................................... 2-105
2-39 Pitch Link (406-312-103) — Damage Limits ....................................................... 2-106
2-40 Nut (406-012-113) — Damage Limits ................................................................. 2-107
2-41 Counterweight Support (206-011-750) — Damage Limits.................................. 2-108
2-42 Clamp Ring (406-012-105 and 427-012-106) — Damage Limits ....................... 2-109
2-43 Driver Plate (406-012-104) — Damage Limits.................................................... 2-110
2-44 Spacer (406-012-110) — Damage Limits ........................................................... 2-111
2-45 Weight Support (406-012-107) — Damage Limits.............................................. 2-112
2-46 Lever Assembly (206-011-741) — Damage Limits ............................................. 2-113
2-47 Idler Assembly (406-012-127) — Damage Limits ............................................... 2-114
2-48 Control Tube Assembly (406-012-118) — Damage Limits ................................. 2-115
2-49 Support Assembly (206-001-825) — Damage Limits ......................................... 2-116
2-50 Bellcrank Assembly (206-001-824) — Damage Limits ....................................... 2-117
2-51 Link Assembly (206-001-823) — Damage Limits ............................................... 2-118
2-52 Idler Assembly (206-001-822) — Damage Limits ............................................... 2-119
2-53 Bellcrank Assembly (206-001-821) — Damage Limits ....................................... 2-120
2-54 Bellcrank Assembly (206-001-820) — Damage Limits ....................................... 2-121

TABLES

Table Page
Number Title Number

2-1 Model 206L Series Excitation Frequencies......................................................... 2-28

2-2 Vibration Reduction Maintenance Actions .......................................................... 2-29
2-3 High Altitude Tail Rotor Movelog ........................................................................ 2-34
2-4 Balance Hardware for the High Altitude Tail Rotor ............................................. 2-36
2-5 Tail Rotor Balance Criteria for the High Altitude Tail Rotor................................. 2-37
2-6 TRACU Control Panel — Troubleshooting ......................................................... 2-42
2-6A Tail Rotor Hub Assembly — Non Destructive Inspection.................................... 2-63
2-6B Fluorescent Penetrant Inspection ....................................................................... 2-64
2-7 Required Shims .................................................................................................. 2-70
2-8 Required Shims (Example) ................................................................................. 2-71
2-9 Bearing Centering Measurements ...................................................................... 2-82
2-10 Signature Sheet for Special Inspection............................................................... 2-125
2-11 Component Overhaul Schedule.......................................................................... 2-134
2-12 Tail Rotor Hub Assembly — Configuration ........................................................ 2-136
2-13 Yoke Assembly — Configuration ........................................................................ 2-136

ECCN EAR99 9 JUN 2011 Rev. 2 2-5/2-6

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 BHT-206-SI-2054

OPERATION AND MAINTENANCE

2-1. OPERATION PROCEDURES b. Repeat step a to assemble other three weight

supports.
Refer to BHT-206L4-FMS-19.
c. Identify tail rotor blade assemblies (11) for
2-2. MAINTENANCE PROCEDURES proper position on yoke assembly (8). Identify bolts,
washers, and nuts (1, 6, 7, and 10) for correct
2-3. TAIL ROTOR HUB AND BLADE — positioning to prevent change in spanwise balance.
ASSEMBLY

d. Position yoke assembly (8) in tail rotor blade

MATERIALS REQUIRED assemblies (11) with pitch horn assembly (12)
adjacent to flapping bearing (13). Align bolt holes in
Refer to BHT-ALL-SPM for specifications. blade with bearings in yoke at both ends.

NUMBER NOMENCLATURE
NOTE
C-104 Corrosion Preventive
Compound, Grade 2 Ensure chamfered side of washers goes
against head of bolt.
C-204 Epoxy Polyamide
Primer
NOTE
C-304 Drycleaning Solvent
Do not torque nuts (1) and (6) on blade
bolts at this time. This will be done during
1. Assemble tail rotor hub and blade assembly as static balancing of tail rotor. Additional
follows: washers (17 and 21, Figure 2-3) may be
required during static balancing.

CAUTION e. Install bolt (10, Figure 2-1), with one

washer (10) under head of bolt, and one washer (1)
under nut (1).
D O N O T H A N D L E U N L U B R I C AT E D
COMPONENTS WITH BARE HANDS. f. Place supports (2) on each side of blade
assembly (11), and install bolt (7), with one washer (7)
NOTE under head of bolt, and one washer (6) under nut (6).
Clean components with drycleaning solvent
(C-304). Apply corrosion preventive g. Repeat step e and step f to attach opposite
compound (C-104) to the shanks of bolts. blade.

NOTE h. Apply epoxy polyamide primer (C-204) to

Each support should have two weights (3), mating surfaces of pitch horn assembly (12) and blade
one on each side of support and placed assembly (11). Position pitch horn in blade. Install bolt,
against support. Two weights (4) are also washers, and nut (9) T .
required, on each side of support (2).
Weights (4) are placed against the outside i. Install cotter pin (9).
of weights (3) (Detail A).

a. Attach weights (3 and 4, Figure 2-1) to support j. Repeat step h and step i to install opposite
(2) with bolt and nut (5) T . pitch horn.

ECCN EAR99 16 NOV 2009 Rev. 1 2-7

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BHT-206-SI-2054

13

206_SI_2054_0033_c01

Figure 2-1. Tail Rotor Hub and Blade — Assembly (Sheet 1 of 2)

2-8 Rev. 1 16 NOV 2009 ECCN EAR99

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 BHT-206-SI-2054

1. Nut (MS14144L6) 2 Reqd

Washer (140-007-25-22C4) 2 Reqd
Cotter Pin (MS24665-283) 2 Reqd
2. Support (206-011-750-103) 4 Reqd
3. Weight (212-010-710-109) 8 Reqd
4. Weight (212-010-710-111) 16 Reqd
5. Bolt (NAS6605-15) 4 Reqd
Bolt (NAS6605-16) 4 Reqd
Bolt (NAS6605-17) 4 Reqd
Nut (MS21042L5) 4 Reqd
6. Nut (MS14144L6) 2 Reqd
Washer (140-007-25-22C4) 2 Reqd
Cotter Pin (MS24665-283) 2 Reqd
7. Bolt (NAS6606D36) 2 Reqd
Bolt (NAS6606D37) 2 Reqd
Bolt (NAS6606D38) 2 Reqd
Bolt (NAS6606D39) 2 Reqd
Washer (140-007-25-22C4) 2 Reqd
8. Yoke Assembly (406-012-102-107) (Kit -101)
Yoke Assembly (406-012-102-113) (Kits -111, -113 and -117)
9. Bolt (NAS6204-29D) 4 Reqd
Washer (AN960-416) 8 Reqd
Nut (MS14144L4) 4 Reqd
Cotter Pin (MS24665-132) 4 Reqd
10. Bolt (NAS6606D30) 2 Reqd
Bolt (NAS6606D31) 2 Reqd
Bolt (NAS6606D32) 2 Reqd
Bolt (NAS6606D34) 2 Reqd
Bolt (NAS6606D36) 2 Reqd
Bolt (NAS6606D38) 2 Reqd
Washer (140-007-25-22C4) 2 Reqd
11. Blade Assembly (Ref)
12. Pitch Horn Assembly (406-012-108-101)
13. Flapping bearing (Ref)

100 TO 140 IN-LB

1 (11.30 TO 15.82 Nm)

60 TO 80 IN-LB
2 (6.78 TO 9.04 Nm)

150 TO 175 IN-LB

3 (16.9 TO 19.8 Nm)

Install using epoxy polyamide primer (C-204) on faying surface of pitch horn and blade.

NOTES

1 Length of bolt to be selected to accommodate weight required to achieve balanced pedal force.

2 Nut is installed toward direction of rotation on outboard side of blade only.

3 Length of bolts to be within range shown to accommodate balance washers.

4 Weights to be shipped with hub and blade assembly for use in balancing pedal force
after installation on helicopter.
NO OBJECT BEYOND THIS POINT 206_SI_2054_0034_c02+

Figure 2-1. Tail Rotor Hub and Blade — Assembly (Sheet 2 of 2)

ECCN EAR99 9 JUN 2011 Rev. 2 2-9

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BHT-206-SI-2054

2-4. TAIL ROTOR HUB AND BLADE — STATIC SPECIAL TOOLS REQUIRED
BALANCE

NUMBER NOMENCLATURE
2-5. Static Balance With Tool Kit A — Setup
90-094-18 Nut
NOTE 206-210-100-103 Static Balance
2
Operators who have a balance set Adapter, Consisting
(T101576) need only to purchase a static of:
balance adapter (206-210-100-103),
allowing modification to balance set 206-210-100-105 Spacer
(T101576) for balancing the 206L4 high
altitude tail rotor hub and blade assembly. 206-210-100-107 Cone

206-210-100-109 Clamp

SPECIAL TOOLS REQUIRED 206-210-100-111 Fitting (Qty 2)

206-210-100-113 Plug
NUMBER NOMENCLATURE
206-210-100-115 Washer (Qty 2)
206-210-100-101 1 Static Balance Kit,
Consisting of: 90-094-18 Nut

206-210-100-105 Spacer T101576 3 4 Balance Set,

Consisting of:
206-210-100-107 Cone
T101576-3 Mandrel Assembly
206-210-100-109 Clamp
T101576-7 Stand Assembly
206-210-100-111 Fitting (Qty 2)
T101576-13 Base
206-210-100-113 Plug
T101576-19 Plate
206-210-100-115 Washer (Qty 2)
T101576-29 Plug
T101544-5 Spacer
NOTES:
T101576-3 Mandrel Assembly
1 Includes balance set (T101576) and static
T101576-7 Stand Assembly balance adapter (206-210-100-103).

T101576-13 Base 2 To be used with balance set (T101576).

T101576-29 Plug 3 Used on Model 206.

NAS1149F0463P Washer (Qty 2) 4 To be used with static balance adapter

(206-210-100-103).
NAS1149F0663P Washer

NAS1351-6-28 Screw 1. Level and check balance of tail rotor balancing

tools as follows:
NAS509-4 Nut (Qty 2)
a. Place stand assembly (9, Figure 2-2) on a
NAS6605-35 Bolt (Qty 2) stable support or workbench in a draft free room. The
support shall have a top constructed from material
3604 BLK Level
such as steel to prevent legs of stand assembly from

2-10 Rev. 2 9 JUN 2011 ECCN EAR99

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 BHT-206-SI-2054

Figure 2-2. Static Balance — Tool Kit A (Sheet 1 of 2)

ECCN EAR99 16 NOV 2009 Rev. 1 2-11

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BHT-206-SI-2054

1. Level (3604BLK)
2. Screw (NAS1351-6-28)
3. Washer (NAS1149F0663P)
4. Plug (T101576-29)
5. Yoke Assembly (Ref)
6. Fitting (206-210-100-111) 2 Reqd
7. Base (T101576-13)
8. Mandrel Assembly (T101576-3)
9. Stand Assembly (T101576-7)
10. Spacer (T101544-5)
11. Nut (NAS509-5) 2 Reqd
12. Washer (206-210-100-115) 2 Reqd
13. Washer (NAS1149F0563P) 2 Reqd
14. Bolt (NAS6605-36) 2 Reqd
15. Clamp (206-210-100-109)
16. Spacer (206-210-100-113)
17. Nut (90-094-18)
18. Cone (206-210-100-107)
19. Spacer (206-210-100-105)
20. Plate (T101576-19)
21. Screw (NAS1351-4-28)

15-25 IN-LB
1 (1.70 TO 2.26 N-m)

HAND TIGHT
2

NOTE

1 Index tools 1, 4, 15, 18, 19, 7, 8, 10 and 9 with pencil or ink

to keep tools aligned during balance procedures.

NO OBJECT BEYOND THIS POINT 206_SI_2054_0076_c01

Figure 2-2. Static Balance — Tool Kit A (Sheet 2 of 2)

2-12 Rev. 1 16 NOV 2009 ECCN EAR99

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 BHT-206-SI-2054

pressing in and causing change in level. If drilling is 2. Balance tail rotor assembly as follows:
not desired, an alternate procedure is to make a pencil
outline of stand assembly on support stand or work
a. Install tail rotor hub and blade assembly with
bench.
the blades flat surface up, on base (7).

b. Place plate (20) on top of stand assembly (9).

Place level (1) on plate. Adjust screws (21) in base of b. Carefully place tail rotor assembly on stand
stand to level stand. Remove level and plate. assembly (9) to prevent damage to ball in mandrel
assembly (8).

c. Place cone (18) on tail rotor trunnion and

CAUTION secure with nut (17) T .

d. Place clamp (15) on yoke assembly (5) and

M A K E S U R E S P A C E R, B A L L , A N D
plug (4) on clamp (15). Secure with washer (3) and
PACKING ARE INSTALLED IN MANDREL.
screw (2).
C A R E F U L LY P L A C E M A N D R E L O N
S TA N D A S S E M B LY T O P R E V E N T
D A M A G E T O S PA C E R , B A L L , A N D e. Position fittings (6) in rotor blade pitch horns
PACKING. and secure with bolts and washers. Secure fittings (6)
to base (7) with bolts (14), washers (12 and 13), and
c. Install fittings (6) on base (7) and push them nuts (11).
inboard in bottom of slots.
f. Place level (1) in recess on top of plug (4) and
d. Place spacer (10) and base (7) on mandrel check balance. Make sure mandrel assembly (8) is
assembly (8) and place mandrel carefully on stand centered on stand.
assembly (9).
g. If the tail rotor assembly is out of balance, do a
e. Place spacer (19) on mandrel assembly (8) spanwise static balance adjustment (paragraph 2-7)
and cone (18) on spacer (16). and a chordwise static balance adjustment (paragraph
2-8).
f. Install nut (17) T until first upper thread is
exposed. 2-6. Static Balance With Tool Kit B — Setup

g. Place clamp (15) and plug (4) on mandrel

assembly (8). Do not install washer (3) and screw (2)
SPECIAL TOOLS REQUIRED
at this time.

h. Place level (1) in recess on top of plug (4) and NUMBER NOMENCLATURE
check if assembly is in balance. If assembly is not in
balance, lay small washers on base (7) to attain T101280-111 1 Static Balance Kit,
balance. When assembly is balanced, attach washers Consisting of:
to base with tape and recheck balance.
T101280-105 Base
i. Index mark all parts with felt tip pen or pencil
T101280-107 Lock (Qty 2)
to facilitate balance alignment of parts.
T101280-109 Adapter
j. Remove level (1), plug (4), clamp (15),
nut (17), and cone (18). AN960-416 Washer (Qty 2)

k. Remove spacer (19), mandrel assembly (8), NAS1351-3-10 Screw (Qty 2)

base (7), and spacer (10) as an assembly from stand
NAS6604H22 Bolt (Qty 2)
assembly (9). Push fittings (6) outboard.

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SPECIAL TOOLS REQUIRED (Cont) b. Install arbor (2) in fixture (11). Tighten
setscrews (13) to secure arbor in fixture.

NUMBER NOMENCLATURE c. Install adapter (12) on arbor (2).

2516 3 Bushing Arbor
d. Place tail rotor assembly (3) on arbor (2) with
(3165) Assembly
flat side of blades facing up.
2532 2 Fixture
(3152) e. Install base (9) on arbor (2).

2533 Bushing f. Adjust tool sensibility by installing bushing (6)

on arbor (2) with top of bushing at "8" mark on arbor.
2264 7 Cable (Optional) Tighten two setscrews (7) to secure bushing (6) in this
position.
2266 6 Quick Disconnect
(Optional)
g. Loosen setscrews (13) in fixture (11).
2387 4 Hard Eye Quick
Disconnect Coupling h. Tilt assembly and move arbor (2) downward
until bushing (6) is seated on base (9).
3350 5 Stand and Hoist
Assembly (Optional) i. Make sure that all components are seated and
tighten setscrews (13 and 14) securing arbor (2) to
NOTES: fixture (11).

1 To be used with Marvel tools.

j. Install two locks (8) between pitch horns (1)
Includes bushing 2537. and fixture (11). Secure locks with screws (10) and
2
bolts attached to pitch horns.
3 This tool incorporates a removable loop
connection that can be attached to a shop k. Loosen setscrew (4) of indicator collar (5).
hoist. Use feeler gauge to position indicator collar (5), 0.004
to 0.006 inch (0.102 to 0.152 mm) from collar of arbor
4 Required with arbor assembly 2516 if boss.
suspended from a shop hoist. Optional with
arbor assembly 3165. 2. Set up balance stand and hoist.

5 May be used if a shop hoist is not available.

3. Attach cable of balance stand and hoist to
To be used with stand and hoist assembly arbor (2).
6
3350. May be used with arbor assembly
2516 or 3165. Requires cable assembly 4. Raise tail rotor and balance set approximately
2264. 0.25 inch (6.35 mm) from workstand.

7 To be used with stand and hoist assembly 5. Check balance indicator on arbor for balance
‘ 3350 and quick disconnect 2266. condition of tail rotor. See Detail A.

1. Set up T101280-111 balance set and install tail a. If tail rotor assembly is out of balance, do a
rotor assembly as follows: spanwise static balance adjustment (paragraph 2-7)
and a chordwise static balance adjustment (paragraph
a. Place fixture (11, Figure 2-3) on flat top bench. 2-8).

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Figure 2-3. Static Balance — Tool Kit B, Spanwise and Chordwise Balance (Sheet 1 of 3)

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Figure 2-3. Static Balance — Tool Kit B, Spanwise and Chordwise Balance (Sheet 2 of 3)

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Figure 2-3. Static Balance — Tool Kit B, Spanwise and Chordwise Balance (Sheet 3 of 3)

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2-7. Spanwise Static Balance — Adjustment c. Use a maximum combination of six AN970-6
washers (21), two NAS1149F0663P washers (17) and
two NAS1149F0632P washers (17) on outboard blade
bolts (20).
MATERIALS REQUIRED

Refer to BHT-ALL-SPM for specifications. d. Use correct length for bolt (20) to secure
washers.
NUMBER NOMENCLATURE
4. At inboard bolt (19), proceed as follows:
C-101 Corrosion Preventive
Compound, Grade 1

CAUTION
1. Where necessary, remove cotter pins (15,
Figure 2-3), nuts (16), and washers (17 and/or 21) if
installed. Leave recessed washers (18) on blade DO NOT USE A SINGLE WASHER (17)
surface for outboard bolt (20) and on counterweight NEXT TO RECESSED WASHER (18).
bracket for inboard bolt (19). WASHER (17) MAY DEFORM CAUSING A
REDUCTION IN BOLT TORQUE.

NOTE a. At inboard side of blade, install recessed

Spanwise balance of the tail rotor assembly washer (18) on counterweight surface.
is done by addition of weights (washers) on
blade bolts. Remove excess weight from b. Install heaviest washer (17) nearest to
heavier side of blades before adding recessed washer (18).
weights (washers) to lighter side of blades.
c. Use a maximum combination of two
2. Determine and install required number of NAS1149F0663P washers (17) and two
washers (17 and/or 21) on bolt (20) to get spanwise NAS1149F0632P washers (17) on inboard blade
balance. bolts (19).

d. Use correct length for bolts (19) to secure

NOTE washers.

Heads of bolts (20) must be installed on 5. Install nuts (16) T .

inboard surface of blades.
6. Install cotter pins (15).
3. At outboard bolts (20), proceed as follows:

7. Apply a coat of corrosion preventive compound

(C-101) to nuts (16), washers (17) and (18), bolts (19)
CAUTION and (20) exposed threads and heads.

2-8. Chordwise Static Balance — Adjustment

DO NOT USE A SINGLE WASHER (17)
NEXT TO RECESSED WASHER (18).
WASHER (17) MAY DEFORM CAUSING A MATERIALS REQUIRED
REDUCTION IN BOLT TORQUE.
Refer to BHT-ALL-SPM for specifications.
a. At outboard side of blade, install recessed
washers (18) on blade surface. NUMBER NOMENCLATURE

C-101 Corrosion Preventive

b. Install heaviest washer (21) nearest to
Compound, Grade 1
recessed washer (18).

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NOTE
NOTE
The chordwise balance of the tail rotor
Prior to accomplishment of rigging, make
assembly is done by the addition of weights
sure all control tubes, links, and bellcranks
on the weight supports. Remove the
are installed and that all controls at rigging
excess weight from the heavier side of the
points are disconnected.
blades before adding weights (washers) to
the lighter side of the blades. To find the
necessary number of washers, install them When a rigging procedure requires a
temporarily on the applicable mounting specific position of the pilot directional
bracket. pedals to accomplish that portion of the
system rigging, it will be held in that
1. Determine and install the required number of position either by hand or mechanical
washers (24 and/or 25, Figure 2-3) to get the means.
chordwise balance as follows:
When rigging to a gap dimension, direct
measurement or shim stock may be used.
a. Use a maximum of three washers (24) under Tolerance for rigging dimensions to be
bolt head and a maximum combination of three ±0.03 inch (±0.76 mm) except as noted.
washers (24) and three washers (25) under nut.

Apply corrosion preventive compound

NOTE (C-104), Grade 2 to threads of all
adjustable rod end bearings and clevis.
Use bolts (26) of proper length to During rigging adjustments, thread
accommodate balance washers on blade engagement shall be sufficient to cover
bolts. The head of the bolt must be installed inspection holes where holes exist and
on the pitch horn side. have a maximum 1.0 inch (25.4 mm)
exposed threads after adjustment.
b. Install bolts (26) with proper amount of
washers (24 and 25). After adjustment, torque control tube jam
nut to 80 to 100 inch-pounds (9.0 to
c. Install nut (23) T . 11.3 Nm) unless otherwise specified. Each
control tube and pitch change link
assembly must be free to rotate several
d. Apply a coat of corrosion preventive
degrees about its longitudinal axis. Upon
compound (C-101) to nut (23), exposed threads and
completion of all rigging procedures,
heads of bolts (26), and washers (24 and/or 25).
operate the controls through complete
travel to check for freedom of operation,
2-9. DIRECTIONAL CONTROL SYSTEM — binding, or interference.
RIGGING
1. Set pedal assembly (1, Figure 2-4) to mid-travel
with pedal adjuster (2).
MATERIALS REQUIRED
2. Disconnect adjustable control tube (11) from
Refer to BHT-ALL-SPM for specifications.
bellcrank (15).
NUMBER NOMENCLATURE

C-101 Corrosion Preventive 3. Disconnect adjustable control tube (5) from

Compound, Grade 1 bellcrank (16).

C-104 Corrosion Preventive

4. Disconnect control rod assembly (19) from
Compound, Grade 2
bellcrank (21).

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Figure 2-4. Rigging — Directional Control System (Sheet 1 of 5)

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Figure 2-4. Rigging — Directional Control System (Sheet 2 of 5)

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Figure 2-4. Rigging — Directional Control System (Sheet 3 of 5)

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Figure 2-4. Rigging — Directional Control System (Sheet 4 of 5)

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Figure 2-4. Rigging — Directional Control System (Sheet 5 of 5)

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 BHT-206-SI-2054

5. Position and hold pilot left pedal forward against

stop. Set bellcrank (16) to a dimension of 1.46 inches
CAUTION
(37.08 mm) from floor line as shown in Detail B. Adjust
control tube (5) to fit bellcrank (16). Torque jam nut
and connect control tube to bellcrank. Cycle pedals.
WHEN RIGGING WITH THE T101751
RIGGING TOOL INSTALLED ON EITHER
6. Position and hold pilot right pedal full forward THE FORWARD OR AFT TAIL ROTOR
against stop. BLADE, THE LEADING EDGE OF THE
BLADE MUST BE AGAINST THE
RIGGING TOOL, AS SHOWN IN
7. Verify 0.040 inch (1.02 mm) gap exists between
DETAIL C.
control tube (6) and control tube (8), as shown in
Detail H. 14. Install rigging tool (17) or workaid 3.5 inches
(88.90 mm) from tip of forward tail rotor hub and
8. If minimum gap does not exist, adjust control tube blade (12). Secure tool with elastic retainers or wing
(5) to obtain gap of 0.040 inch (1.02 mm) minimum, nuts. Position and hold the tail rotor blade
but do not exceed 0.070 inch (1.77 mm). perpendicular to the tail rotor mast, as shown in
Detail G.
9. Torque jam nut 80 to 100 inch-pounds (9.04 to
11.30 Nm) and reconnect tube (5) to bellcrank (16). NOTE
If available, install a second rigging tool
(17) or workaid 3.5 inches (88.90 mm) from
NOTE
tip of aft tail rotor hub and blade (12).
A workaid may be fabricated to position the
(206-001-820) bellcrank 0.37 inch
(9.40 mm) aft of the bellcrank support. NOTE
As an alternate method of positioning the
10. Run ratio change actuator (28) to fully extended tail rotor perpendicular to the tail rotor mast,
(RIG MAX) position using the Tail Rotor Authority install T101752-101 centering tool halves
Control Unit (TRACU) control box. Move bellcrank (15) or equivalent workaid around the tail rotor
to position 0.37 inch (9.40 mm) aft of vertical support, mast spacer located inboard of tail rotor of
as shown in Detail K. Secure in position. the tail rotor hub and blade assembly and
install both retaining screws, but do not
tighten. Push centering tool outboard until
11. With bellcrank positioned per step 5, and pilot left
both tool halves are in contact with the rotor
pedal full forward against stop, adjust control tube (11)
yoke, then secure tool in position with tool
to fit walking beam (10). Torque jam nut 80 to 100
screws, as shown in Detail J.
inch-pounds (9.04 to 11.30 Nm) and connect control
tube (11) to walking beam (10). 15. With tail rotor blades positioned per step 13 and
step 14, place a propeller protractor or equivalent on
12. Apply forward hand pressure to top of outboard surface of rigging tool (17) or equivalent
bellcrank (15) to remove system freeplay and check workaid and record blade angle. See Detail C.
for 0.37 inch (9.40 mm) dimension specified in
step 10. If dimension is not correct, readjust control 16. Repeat step 15 on aft tail rotor blade and record
tube (11) until bellcrank (15) is within specified limits of blade angle.
step 10.
17. Move the tail rotor crosshead outboard toward left
13. Using a protractor on the leading edge of the pedal position until a mean tail rotor blade angle of
forward tail rotor blade, position tail rotor hub and 27.75 to 28.25° is obtained. See Detail L.
blade (12) within 0.5° of horizontal, as shown in
Detail G. A stand or prop may be used to hold the tail 18. With the pilot left pedal full forward against stop
rotor hub and blade assembly in this position. and the tail rotor blades positioned per step 17, adjust

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control rod assembly (19) to fit bellcrank (21). Torque 23. Coat rod end bearing threads, jam nuts on
jam nut and connect control rod assembly to bellcrank, adjustable control tubes (5 and 11), and rod assembly
as shown in Detail D. (19) with corrosion preventive compound (C-101).

24. Check complete tail rotor control system to make

19. With tail rotor still positioned per step 17, check
sure that all safety devices (cotter pins, lockwire, jam
for minimum gap of 0.05 inch (1.27 mm) between
nuts, etc.) are installed and secured.
rod (19) and idler (18), as shown in Detail D.
25. Perform pedal friction adjustment prior to ground
20. Cycle pedals. Position pilot left pedal full forward run (paragraph 2-10).
against stop, then apply a force of 35 pounds
(15.87 kg) by hand, inboard to the tail rotor crosshead 2-10. PEDAL FRICTION ADJUSTMENTS
to remove system freeplay. Release force on
crosshead and check for a mean blade angle of 27.75 2-11. COUNTERWEIGHT ADJUSTMENT
to 28.25°. Check for minimum gap of 0.05 inch (1.27
mm) between the idler assembly (18) and rod Pedal friction adjustments shall be accomplished after
assembly (19), as shown in Detail D. If rigging tail rotor control rigging is completed and helicopter is
dimensions are not within required limits, repeat step 5 prepared for ground run-up and flight test.
through step 19.
1. Make sure that static balance of tail rotor hub and
blade assembly has been accomplished.
NOTE
2. Dynamic balance of tail rotor hub and blade
For rigging purposes, the system control
assembly may be accomplished in conjunction with
unit may be put into the rig mode by
the following procedures:
pushing the "MODE" button IN on the
TRACU panel while pushing T/R AUTH
a. Check pedal assembly for freedom of
circuit breaker IN. This action will cause the
movement.
TRACU panel to display RIG MAX and run
the actuator to its full extend position. A
b. Remove all friction from clamp (24, Figure 2-4,
second push of the "MODE" button will
Detail E) by loosening nut on screw (22).
reverse the direction to fully retract the
actuator, and the panel will display RIG c. Adjust pedal friction as follows:
MIN. Each subsequent push of the "MODE"
button will reverse the direction of the (1) Place pedal assembly (1) in neutral
actuator. position.

21. Electrically retract (RIG MIN) the ratio change (2) Use a spring scale positioned
actuator (28) using (TRACU) control box. Position pilot perpendicular to and connected to pedal. Check for a
left pedal full forward against stop, then apply a force force of 6 to 10 pounds (2.73 to 4.54 kg) required to
of 35 pounds (15.87 kg) by hand, inboard to the tail move pedal from neutral position.
rotor crosshead to remove system freeplay. Release
force on crosshead and check for mean tail rotor blade (3) Adjust nut on screw (22) at clamp (24)
angle of 21.75 to 22.75°. If the mean tail rotor blade until desired friction of 6 to 10 pounds (2.73 to 4.54 kg)
angle is not within the required limits, repeat step 5 is obtained. Do not exceed torque of 15 inch-pounds
through step 19. (1.69 Nm) on screw (22) and nut.

22. Remove rigging tool (17) or workaid from tail rotor NOTE
hub and blades (12). Check for freedom of operation The basic weight arrangements should be
of each pitch link, with tail rotor blades flapped to both one weight (3, Figure 2-1) on each side of
extreme positions. Check with pedal assembly (1) at support (2) and one weight (4) on outboard
full right position, then at full left position. side of each weight (3), as shown in

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Detail A. At this time, a total of eight

NOTE
weights (3) and eight weights (4) are
installed on the assembly. Do not exceed 16 weights (4) total.

d. Check counterweight inboard and outboard e. If left pedal continues to creep forward, add an
supports (2) to ensure correct quantity and type of additional weight (4) at each location. Repeat step b
weights are installed. All four supports should have through step d, if necessary.
identical weight arrangements.
f. If the right pedal creeps forward, perform the
e. Perform dynamic balance of tail rotor hub and reverse of the procedures in step b through step e.
blade assembly (paragraph 2-12).
g. If pedal forces are still unacceptable after
these adjustments, contact Product Support
NOTE Engineering.
Do not use weights (3) for pedal creep
adjustment. They must remain installed, 2-12. DYNAMIC BALANCE
one on each side of support (2).
2-13. RADS-AT HARDWARE AND SOFTWARE
REQUIREMENTS
CAUTION
2-14. RADS-AT Hardware

MAKE SURE CIRCUIT BREAKER (9CB2)

The GE Aviation RADS-AT is a vibration analysis and
IS CONNECTED TO 28 VDC BUS.
rotor smoothing system approved by Bell Helicopter
Textron for maintaining the Model 206L Series (206L/
3. Perform test flight and check pedal balance, at
206L1/206L3/206L4). The RADS-AT hardware used
normal cruise airspeed, as per the BHT-206L4-FM-1 on the Model 206L Series are:
and as follows:

a. Release foot pressure from pedal and observe SPECIAL TOOLS REQUIRED
pedal movement from trimmed position.

NUMBER NOMENCLATURE
NOTE
SA# 29333301 Basic RADS-AT Kit
After adjustment, weight arrangements
should be identical on both blades. SA# 29335500 206 Series Adapter Kit

b. If left pedal creeps forward, remove the trailing

In addition to this hardware, sunshield SA# 29722100
edge weight (4) on inboard support (2) and reinstall on
is recommended to improve tracker performance in
leading edge side.
sunny conditions. This sunshield incorporates special
filters and has superior performance compared to
c. Release foot pressure from pedal and observe simple tube type sunshields.
pedals movement from trimmed position.
The number of engine starts/flights required to
d. If left pedal continues to creep forward, accomplish all tasks can be reduced by conducting
remove the leading edge weight (4) on outboard multiple tasks on the same flight. To conduct multiple
support (2) and reinstall on trailing edge side. tasks the following hardware is recommended:

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This software includes all functions to control main

SPECIAL TOOLS REQUIRED rotor 1/rev, control tail rotor 1/rev, and conduct general
vibration troubleshooting. Updates to this software will
be controlled by future Maintenance Manual revisions.
NUMBER NOMENCLATURE

SA# 28110900 One extra Wilcoxon 2-16. SOURCES AND LIMITS FOR VIBRATION
991D Accelerometer
All rotating components generate vibration due to
SA# 29105600 One additional 15 foot
(4.57 m) Accelerometer imbalances in mass and/or aerodynamics. A certain
Cable level of vibration from each source is normal and
unavoidable. Table 2-1 lists the primary sources of
vibration and the frequency at which the vibration
2-15. RADS-AT Software occurs at 100% main rotor RPM. The magnitude of
each of these vibrations is controlled by either the
To use the RADS-AT on the Model 206L Series (206L/ amount of force generated or the sympathy of
206L1/206L3/206L4), the following "Aircraft Type"
individual components to the generated force. The
software is required:
"normal" level of vibration is dependent upon location,
loading, and flight condition. Consistency in measuring
206L Version 7.0 vibration levels needs to take these into account along
with how the vibration sensor is mounted. Table 2-2
206LF Version 7.0 (Aircraft with floats) lists the maintenance actions currently supported by
TRAC Version 7.0 (Aircraft with high the RADS-AT.
altitude; P/N 206-704-722 tail
rotor kit)

Table 2-1. Model 206L Series Excitation Frequencies

206L FREQUENCIES

VIBRATION SOURCE (RPM) (HZ)

1/REV Main Rotor 394 6.57

2/REV Main Rotor 788 13.13
4/REV Main Rotor 1576 26.27
6/REV Main Rotor 2364 39.40
1/REV Tail Rotor 2550 42.50
8/REV Main Rotor 3152 52.53
2/REV Tail Rotor 5100 85.00
1/REV Main Driveshaft 6016 100.27
1/REV Tail Rotor Driveshaft 6016 100.27
4/REV Tail Rotor 10 200 170.00
1/REV Hydraulic Pump 30 625 510.42
1/REV Power Turbine 30 650 510.83
Planetary Gear Mesh 39 000 650.00

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Table 2-2. Vibration Reduction Maintenance Actions

WHEN TASK SHOULD BE

MAINTENANCE TASK PARAGRAPH
CONDUCTED

Balance the tail rotor After any change to the tail rotor 2-17
assembly
At 100 flight hour increments
(recommended)
When the flight or ground crew
complain of high frequency
vibration

2-17. TAIL ROTOR BALANCING photocell bracket with the photocell forward and the
lens pointing at the tail rotor, as shown in Figure 2-5.
2-18. Purpose
d. Insert a Wilcoxon 991 accelerometer into the
hole on the side of the photocell bracket so that the
This section describes the balancing of the tail rotor to cable connector is pointed toward the tail rotor. Secure
reduce tail rotor 1/rev vibration. The "Tail" "Flight Plan" the accelerometer using a MS21042L4 self-locking
is used for balancing the standard tail rotor on Model nut.
206L Series. The "TRAC" "Flight Plan" is used for
balancing the high attitude tail rotor kit (206-704-722).
The installation of the RADS-AT permits these e. Connect the accelerometer end of the 50-foot
procedures to be conducted concurrently with cable (291056000) to the tail rotor accelerometer.
balancing the main rotor (using an extra
accelerometer and a 50-foot length (15.24 mm) f. Route the optical RPM sensor cable and
accelerometer cable or independently with no main accelerometer cable down the side of the tailboom
hardware installed. opposite the tail rotor to the cabin. For ground run,
secure both to ensure that neither can foul the rotating
components of the aircraft or block the photocell lens
2-19. Balancing the High Altitude Tail Rotor during operation.

2-20. RADS-AT — Installation g. On the DAU connect the optical RPM sensor
cable to TACHO # 2 and the accelerometer cable to
1. To balance the tail rotor assembly, install the ACC4.
RADS-AT as follows:
h. Connect the 28 VDC power chord (29104700)
to the 28 VDC outlet on the left side of the instrument
a. Install and secure the DAU in the aft cabin pedestal near the copilot foot intercom switch.
with the connectors up. Connect the other end to the 28 VDC port on the DAU.

b. Attach the optical RPM sensor (29314799) to i. Cut two pieces 2.5 inches (63.5 mm) long by
the tail rotor optical RPM sensor bracket (293338501) 1 inch (2.54 mm) wide of reflective tape from the roll
with No. 440 self-locking nuts in such a way that the (1060500).
lens is next to the vertical leg of the bracket, as shown
in Figure 2-5.
j. Install one piece of reflective tape on the
tailboom side of one tail rotor blade starting 2 inches
c. Remove the bottom forward screw of the 90° (50.8 mm) outboard of the outer blade bolt, as shown
gearbox fairing and (using a longer bolt) install the in Figure 2-5.

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Figure 2-5. Schematic of RADS-AT Installation for Tail Rotor Balancing on the Model 206L Series

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 BHT-206-SI-2054

c. Once the "Aircraft Type" and "Tail Number"

NOTE
have been selected, select "206L4" as the "Flight
The blade with the tailboom side is the Plan."
target blade.
d. With the CADU properly configured as
k. As a counter balance, install the second piece illustrated in Figure 2-7, press F1 to initiate the
of reflective tape on the opposite tail rotor blade at the measuring sequence. Once pressed, the test condition
same location, but on the side away from the tailboom. at which data will be taken will be displayed on the
screen.
l. With power to the DAU, slowly rotate the tail
rotor. Observe the red light on back of the optical RPM NOTE
sensor. It should be off until the reflector is viewed by
the sensor. Operate the aircraft as dose to 100% RPM
as possible.
m. Once in view, the red light should illuminate.
e. Center the cyclic; make sure that the
collective is down and press the left directional pedals
n. Flap the tail rotor to ensure the light stays on forward 1.5 inches (38.1 mm).
throughout the flapping range. If the light does not
illuminate or stay on, troubleshoot as follows: f. With the "100% Nr" test state highlighted,
press "DO" to arm the RADS-AT.
(1) Verifying that the optical RPM sensor is
getting power. g. If all internal checks are successful then the
test condition title will appear at the bottom of the
(2) Adjusting the reflector until the red light screen and the system will be armed to take data.
illuminates.
h. Press "DO" again to acquire the data. If the
o. The RADS-AT is now installed to balance the data has been successfully obtained, the RADS-AT
tail rotor. See Figure 2-6 for a schematic of the will indicate that the test has been completed.
installation.
i. Select "Finish" then "Diagnostics" to review
the tail rotor 1/rev levels and determine if any
2-21. Obtaining Tail Rotor Balance Data
adjustments are required.

1. Check and correct tail rotor balance as follows: j. If a "TACHO" error occurs during data
acquisition, repeat the test at least two times. If the
failure still occurs conduct the following:
NOTE
The RADS-AT is operating on preset limits (1) Shut down aircraft.
of 0.2 IPS for tail rotor balance. If the
operator desires to reduce the level to (2) Inspect to ensure the reflective tape is
below 0.2 IPS, then this can be done by still in place and is clean. Replace if necessary.
pressing "do" from the limits screen. The
RADS-AT will specify the adjustments (3) With power to the DAU, verify that the red
required to achieve a "0.0" IPS balance. light on back of optical RPM sensor illuminates when
the reflector is in front of the optical sensor.
a. With the RADS-AT installed as described in
paragraph 2-20, select "TRAC" as the "Aircraft Type" (4) Verify that the optical RPM sensor is
on the CADU main menu. hooked to TACHO #2.

b. Once the "Aircraft Type" has been selected, (5) If all of the above conditions are met, and
select or create the "Tail Number" for the aircraft to be if the red light still does not illuminate, remove the
worked. clear cover from the optical RPM sensor.

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Figure 2-6. Schematic of RADS-AT Installation for Tail Rotor Balancing

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Figure 2-7. Proper CADU Main Menu Display for Conducting Tail Rotor Mode for the Model 206L
With the High Altitude Tail Rotor Kit

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(6) Gently turn the brass screw clockwise to k. If the tail rotor requires balancing, record the
increase the gain until a slight click is felt. recommended adjustments to be made on a copy of
the "Tail Rotor MoveLog" for the high altitude tail rotor
form (Table 2-3).
(7) With the optical RPM sensor pointing at
the reflector, the red light should illuminate during this
l. Repeat step a through step k until the tail rotor
process.
is balanced.

(8) Reinstall the clear plastic cover.

Table 2-3. High Altitude Tail Rotor Movelog

SHIP TYPE AND SERIAL NUMBER:

FLIGHT ID LOCATION MOVE/READING COMMENTS

Outer Blade Bolt
Inner Blade Bolt
Chord Balance
1/REV Reading

FLIGHT ID LOCATION MOVE/READING COMMENTS

Outer Blade Bolt
Inner Blade Bolt
Chord Balance
1/REV Reading

FLIGHT ID LOCATION MOVE/READING COMMENTS

Outer Blade Bolt
Inner Blade Bolt
Chord Balance
1/REV Reading

FINAL SETTINGS

LOCATION MOVE/READING
Outer Blade Bolt
Inner Blade Bolt
Chord Balance
1/REV Reading

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2-22. Adjusting Tail Rotor Balance NOTE

Washers AN960-616 are replaced by
The RADS-AT specifies tail rotor balance corrections NAS1149F0663P; washers AN960-616L
as adjustments to the target blade's outboard blade are replaced by NAS1149F0632P.
bolt and chordwise balance arm located as shown in
(a) One washer 104-007-25-22C4 must
Figure 2-8.
be against the blade on each side.

(b) The maximum number of washers

allowed on the outboard blade bolt is six AN970-6,
CAUTION nine AN960-616, and two AN960-616L in any
combination, as long as the total number of washers
does not exceed nine.
DO NOT TURN TWO ADJUSTMENTS OF
THE SAME TYPE OR BOTH THE
(c) The maximum number of washers
INBOARD AND OUTBOARD LOCATIONS allowed on the inboard blade bolt is two AN970-6 and
AT THE SAME TIME. two AN960-616L in any combination.

NOTE NOTE
If fine span adjustments are needed, the Place the largest balance washers against
inboard blade bolt can be used. To specify the washers 104-007-25-22C4 and stack
a move for the inboard bolt, use the "edit the remaining washers so that the lightest
Adjustables" screen to turn off the outboard is next to the head of the bolt or the nut.
span adjustment.
(d) Split the balance washers into two
roughly equal packages; one will go under the head of
1. Adjust tail rotor balance as shown in Figure 2-9 the bolt and one under the nut.
and as follows:

NOTE
a. Review the adjustments recorded on the
If the bolt is changed, the change in bolt
adjustment log.
weight must be taken into account by
adjusting the washer stack.
b. Review the location and size of currently
installed weights. It is best to remove weight when (e) Check the length of the bolt. If
possible. It is acceptable to install weights on both necessary, change the length of the bolt to ensure that
sides to make small adjustments. the cotter key can be installed and that at least two
threads show beyond the end of the nut.

c. Install the required (if any) span balance (3) Once the bolt and weight package has
weight to the outboard or/and inboard tail rotor blade been selected, install the nut and torque to 150 to
bolt as follows: 175 inch-pounds (16.95 to 19.77 Nm) and secure with
a new MS24665-283 cotter pin.
(1) Remove the cotter pin and nut from the
blade bolt at which weight is to be adjusted. d. Install chordwise balance weight (if any) as
follows:

(2) Using the hardware listed in Table 2-4, (1) Inspect the tail rotor to determine the
adjust the washers as required to achieve the required actual adjustment to be made. When possible, weight
balance change with the following restrictions: should be removed to accomplish the adjustment.

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Table 2-4. Balance Hardware for the High Altitude Tail Rotor

MASS
PURPOSE DESCRIPTION P/N QUANTITY
GRAM

OUTBOARD BOLT NAS6606D30 39.26 2

SPAN

NAS6606D31 39.69 2
NAS6606D32 40.83 2

NAS6606D34 42.53 1

NAS6606D36 44.32 1

NAS6606D39 47.08 1

WASHERS AN960-616L 0.76 4

AN960-616 1.28 18

AN970-6 15.08 12
PERMANENT 104-007-25-22C4 N/A N/A
WASHER

NUT MS141144L6 N/A A/R

INBOARD SPAN BOLTS NAS6606D36 44.32 2

NAS6606D38 46.80 2

NAS6606D40 48.60 2

NAS6606D42 50.40 2
WASHERS AN960-616L 0.76 4

AN960-616 1.28 4

NUT MS14144L6 N/A A/R

CHORD BOLTS NAS6204-1 479 ±0.1 2
BALANCE

NAS6204-2 5.27 ±0.1 2

NAS6204-3 5.61 ±0.1 2

NAS6204-4 6.00 ±0.1 2

NAS6204-5 6.37 ±0.1 2

NAS6204-6 6.77 ±0.1 2

NAS6204-7 7.25 ±0.1 2

NAS6204-8 7.76 ±0.1 2

NAS6204-9 8.32 ±0.1 2

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Table 2-4. Balance Hardware for the High Altitude Tail Rotor (Cont)

MASS
PURPOSE DESCRIPTION P/N QUANTITY
GRAM

WASHERS AN960-416 1.09 ±0.04 12

AN960-416L 0.60 ±0.04 A/R

AN970-4 7.17 ±0.1 6

NUT MS21042L4 1.59 ±0.04 A/R

(2) Using the hardware listed in Table 2-4, the head of the bolt toward the pitch horn. Install the
make up the balance package to be installed at the nut and torque 60 to 80 inch-pounds (6.78 to
selected chordwise location. The following restrictions 9.04 Nm).
should be noted:
e. Recheck tail rotor balance after each balance
• The total number of washers that can be adjustment per paragraph 2-21. Repeat until an
installed is nine with a maximum of three acceptable balance has been achieved.
washers AN970-4.

• A maximum of three washers can be placed 2-23. Balance Criteria for the High Attitude
under the head of the bolt. Tail Rotor

• Weight can be installed at both locations to Table 2-5 lists the criteria used to guide tail rotor
achieve small adjustments. balance maintenance on the high altitude tail rotor
system.
(3) Once the bolt, washer, and nut
combination has been defined, install the package with

Table 2-5. Tail Rotor Balance Criteria for the High Altitude Tail Rotor

TAIL ROTOR 1/REV TAILBOOM LATERAL LEVELS < 0.2 NO ACTION

AT 100% RPM RECOMMENDED

0.2 < LEVELS < 0.3 LEVELS

SERVICEABLE,
REDUCE AT
CUSTOMER OPTION.
NO ACTION
REQUIRED
0.3 < LEVELS REDUCE AS SOON AS
PRACTICAL

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Figure 2-8. Balance Locations for High Altitude Tail Rotor

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Figure 2-9. Balancing Chart for 206L4 High Altitude T/R Showing Angles in Hours and Degrees
(for Use With RADS-AT)

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2-24. Tasks to Be Conducted After Balancing 3. Make sure the ENC ALT circuit breaker is pushed
the Tail Rotor in.

4. If an encoding altimeter is used, set the

MATERIALS REQUIRED barometric compensator to 29.92 inches Hg.

Refer to BHT-ALL-SPM for specifications. 2-27. LAMP AND SELF-TEST

NUMBER NOMENCLATURE
NOTE
C-101 Corrosion Preventive
Lamp and self-test are automatically
Compound, Grade 1
sequenced at power-up of the Tail Rotor
C-104 Corrosion Preventive Authority Control Unit (TRACU) controller.
Compound, Grade 2 The events need to be observed and the
cycle repeated, if necessary, to observe
that the proper events occur.
1. At the completion of tail rotor tracking and/or
balancing, do as follows: 1. Pull and reset the T/R AUTH circuit breaker to
cycle power to the Tail Rotor Authority Control System
a. Remove the RADS-AT hardware from the (TRACS), watching the T/R AUTH caution panel
aircraft. segment as power is applied.

b. Reattach the gearbox fairing with a new bolt. 2. Verify that the caution panel segment lamps
illuminate brightly for a few seconds and then
c. Apply corrosion preventive compound extinguish.
(C-104), Grade 2 to the shank of any new bolts. Be
sure not to apply to the threads. 3. Also verify that all dots of the display segments
on the TRACU panel illuminate for a few seconds and
d. Replace all nuts which appear to have lost then produce a display showing the words SELF
their self-locking torque. Retorque to the value listed in TEST, followed by a display of pressure altitude XXXX
the above text. Hp and OAT XX °C, and then, after a few more
seconds, a display of the letter "V" showing the
e. Apply corrosion preventive compound actuator position.
(C-101), Grade 1 to the uncoated bolts, nuts, and
weight packages.
4. Pull the ENC ALT circuit breaker and repeat the
cycling of power to the TRACS system, using the T/R
2-25. TAIL ROTOR AUTHORITY CONTROL AUTH circuit breaker.
UNIT (TRACU) — FUNCTIONAL TEST
PROCEDURES 5. Verify that the previous cycle repeats, but that the
final display shows the words FAIL ENC2.
2-26. SETUP
6. Reset ENC ALT circuit breaker and recycle
TRACS power.
SPECIAL TOOLS REQUIRED

NOTE
NUMBER NOMENCLATURE
If the helicopter is sitting in sunlight,
Commercial Pilot/Static Tester temperature difference may be significant.
If this condition exists, re-check in shade,
hanger, or during flight.
1. Connect external power.
7. Verify that the temperature displayed on the
2. Make sure 28 VDC bus is powered. TRACS panel agrees with OAT as indicated by the

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mechanical thermometer type OAT indicator 12. Verify the actuator % display value changes
within 4°C. to 75% (±5%).

2-28. ALTIMETER DATA TEST 13. Adjust the pitot and static pressures to produce a
density altitude indication of 6600 feet.
1. Connect the pitot/static air system to the
helicopter pitot and static ports, blocking one static 14. Verify the actuator % display value changes
port, if both are not used. to 90% (±5%).

2. Power up the TRACS and allow it to self-test, 15. Adjust the pitot and static pressures to produce a
then press the MODE button on the Tail Rotor density altitude indication of 7500 feet.
Authority Control Unit (TRACU) panel to select the
display of density altitude (Hd) and actuator position.
16. Verify the actuator % display value changes
to 100%.
3. Adjust the pitot and static pressures to produce a
density altitude indication of 2500 feet.
17. Allow the pitot and static pressures to equalize to
actual helicopter elevation and disconnect the pitot/
4. Verify that the actuator position indication static tester.
changes to 0%, if not already at 0%.

2-29. RIGGING MODE TEST

NOTE
Actuator motion is slow and can take over 1. Cycle power to the Tail Rotor Authority Control
3 minutes to go from 100 to 0%. The System (TRACS) while holding the MODE button
motion progress can be observed by the depressed, releasing the button only after resetting the
display changing in 5% increments as the T/R AUTH circuit breaker.
actuator moves.
2. Verify the TRACU panel shows the self-test
5. Adjust the pitot and static pressures to produce a sequence, as above, but display shows RIG MAX,
density altitude indication of 3400 feet. alternating with the ">" position indication, at the end
of the sequence.
6. Verify the actuator % display value changes to
10% (±5%). 3. Verify the display indication changes until the ">"
is at the far right of the display, replacing the right
bracket, "]", symbol.
7. Adjust the pitot and static pressures to produce a
density altitude indication of 4000 feet.
4. Momentarily press the MODE button.
8. Verify the actuator % display value changes
to 25% (±5%). 5. Verify the TRACU panel shows RIG MIN,
alternating with the "<" position indication.
9. Adjust the pitot and static pressures to produce a
density altitude indication of 5000 feet. 6. Verify the display indication changes until the "<"
is at the far left of the display, replacing the left
bracket, "[", symbol.
10. Verify the actuator % display value changes
to 50% (±5%).
7. Functional test procedure complete.
11. Adjust the pitot and static pressures to produce a
density altitude indication of 6000 feet. 8. De-energize 28 VDC bus.

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2-30. TAIL ROTOR AUTHORITY CONTROL words FAILED @ XXX% or FAIL-

UNIT (TRACU) CONTROL PANEL — UNKNOWN. During troubleshooting, the
power-up test must be initiated by pulling
TROUBLESHOOTING
the circuit breaker or turning off the DC bus
power to cause the system to self-test and
NOTE display the more detailed FAIL messages,
without having pushed the MODE button.
Once the MODE button is pushed, system
failure messages will only consist of the

Table 2-6. TRACU Control Panel — Troubleshooting

PARAGRAPH SYMPTOM CORRECTIVE ACTION(S)

2-27, step 2 No caution segment illumination. Press to test caution segment

Replace lamp(s) if no illumination.
If segment lamps OK. Check ships wiring from caution
panel to TRACU.
If wiring OK. Replace TRACU.
2-27, step 3 Dots missing in display. Replace TRACU.
Panel indicates FAIL ENC1. Replace blind encoder or encoding
altimeter.
If blind encoder or encoding altimeter OK. Check wiring from blind encoder or
encoding altimeter to TRACU.
If wiring OK. Replace TRACU.
Panel indicates FAIL ENC2. Check that ENC ALT circuit breaker
is in.
If ENC ALT circuit breaker is in. Replace blind encoder or encoding
altimeter.
If blind encoder or encoding altimeter OK. Check wiring from blind encoder or
encoding altimeter to TRACU.
If wiring OK. Replace TRACU.
Panel indicates FAIL ENC3. Replace blind encoder or encoding
altimeter.
If blind encoder or encoding altimeter OK. Check wiring from blind encoder or
encoding altimeter to TRACU.
If wiring OK. Replace TRACU.
Panel indicates FAIL ATCR. Replace TRACU.
If TRACU OK. Check wiring from actuator to
TRACU.
If wiring OK. Replace actuator.

2-27, step 3 Panel indicates FAIL RVDT. Replace actuator (its RVDT has
failed).
If actuator OK. Replace TRACU.

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Table 2-6. TRACU Control Panel — Troubleshooting (Cont)

PARAGRAPH SYMPTOM CORRECTIVE ACTION(S)

If TRACU OK. Check wiring from actuator to

TRACU.
Panel indicates FAIL TEMP PR. Replace temperature probe.
If temperature probe OK. Replace TRACU.
If TRACU OK. Check wiring from temperature
probe to TRACU.
Panel indicates FAIL UNKNOWN. Recycle power, and do not press
MODE button.
If panel repeats FAIL UNKNOWN display. Replace TRACU.
If TRACU OK. Replace actuator.
If actuator OK. Check wiring from actuator to
TRACU.
2-27, step 5 NO FAIL ENC2 message. Check blind encoder or encoding
altimeter wiring and system.
2-27, step 7 OAT disagrees more than 4°. Check during flight, when OAT probe
and OAT mechanical thermometer
will experience equal temperatures.
If disagrees in flight. Replace TRACU.
If TRACU OK. Replace temperature probe.
If temperature probe OK. Check probe wiring to TRACU.
2-28, step 4 Displayed values are not the expected values. Replace TRACU.
through step 16
If TRACU OK. Replace blind encoder or encoding
altimeter.
If blind encoder or encoding altimeter OK. Check wiring between blind encoder
or encoding altimeter and TRACU.
2-29, step 2 No RIG MAX display. Correct other system faults, if any.
No other system faults. Replace TRACU.
2-29, step 3 ">" does not move. Correct other system faults, if any.
No other system faults. Replace TRACU.

2-29, step 5 No RIG MIN display. Correct other system faults, if any.
No other system faults. Replace TRACU.
2-29, step 6 "<" does not move. Correct other system faults, if any.
No other system faults. Replace TRACU.

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2-31. TAIL ROTOR HUB AND BLADE Four counterweight supports (4) with an equal amount
ASSEMBLY of weights mounted on each side of the two blades are
used to compensate for the centrifugal pitching
2-32. TAIL ROTOR HUB AND BLADE moment. This prevents yaw pedal creep to assist the
ASSEMBLY — DESCRIPTION pilot during boost off flight.

The tail rotor hub and blade assembly includes two tail The tail rotor hub and blades static and dynamic
rotor blade assemblies, a tail rotor hub assembly, and balance are achieved by adding or removing weight
flight control components. The tail rotor assembly is from the blades bolts on the spanwise axis.
installed on the left side of the tailboom. The tail rotor
gearbox drives the tail rotor to a speed of Two weight supports (5) are installed, one on each
approximately 2500 RPM. The tail rotor acts in side of the hub. The weight supports and weights are
opposition to the torque applied to the helicopter by used to balance the tail rotor about its chordwise axis.
the main rotor assembly. The tail rotor assembly gives
directional control around the vertical axis of the 2-33. TAIL ROTOR HUB AND BLADE
helicopter. When you look at the tail rotor assembly ASSEMBLY — CLEANING
from the left side of the tailboom, it rotates clockwise.

The tail rotor assembly is mounted through its hub

MATERIALS REQUIRED
assembly on the output shaft of the tail rotor gearbox.
A mast nut (2, Figure 2-10) attaches the hub assembly
Refer to BHT-ALL-SPM for specifications.
of the tail rotor assembly to the output shaft of the tail
rotor gearbox. NUMBER NOMENCLATURE

The tail rotor hub assembly has a stainless steel C-304 Drycleaning Solvent
yoke (3) and a flapping bearing (8). The flapping
bearing) is made of a splined trunnion that has an C-305 Aliphatic Naphtha
elastomeric bearing at each end. The flapping bearing
is in the center of the yoke and permits the flapping C-318 Cleaning Compound
motion of the tail rotor assembly. The splined trunnion
of the flapping bearing transfers the power of the
gearbox output shaft to the tail rotor.
CAUTION
The tail rotor blade assemblies (1) are attached to the
yoke (3) on four spherical bearings, two for each
blade. The spherical bearings are on the pitch axis of MA KE S URE TH AT THE AL IPHA TIC
the blade and permit the pitch angle of the tail rotor NAPHTHA (C-305) DOES NOT TOUCH
blade assemblies to change. The pitch horn (6) is THE ELASTOMER.
attached to the blade and transfers inputs from the tail
rotor controls to the tail rotor blade assemblies. 1. Clean flapping bearing and elastomer as follows:

The tail rotor blade assemblies (1) are made of a. Clean flapping bearing (8, Figure 2-10) metal
composite materials and they have an asymmetric surfaces with aliphatic naphtha (C-305).
profile with a 7° positive twist built into the grip area.
The leading edge of the blade has an abrasion strip
b. Clean the elastomer with cleaning compound
made of stainless steel. The abrasion strip protects the
(C-318) and water. Rinse with water.
leading edge against the abrasion caused by sand,
water, and other particles.
2. Clean tail rotor blade assembly (1) with cleaning
A flapping stop (9) is installed between the flapping compound (C-318) and water. Rinse with water.
bearing (8) and the flange of the gearbox shaft. The
flapping stop provides a flapping stop to limit tail rotor 3. Clean all the other components of the tail rotor
flapping. assembly with drycleaning solvent (C-304).

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1. Tail Rotor Blade Assembly

2. Mast Nut
3. Yoke
4. Counterweight Support
5. Weight Support
6. Pitch Horn
7. Spacer
8. Flapping Bearing
9. Flapping Stop (Support)

NOTE
Flight controls components are not shown for clarity.

206_SI_2054_0094_c01

Figure 2-10. Tail Rotor Assembly — Description

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4. Dry all the components with filtered compressed 6. Examine the two blades of the tail rotor to find the
air. presence of nicks, dents, scratches, and holes
(paragraph 2-46). Make sure the attaching hardware is
2-34. TAIL ROTOR HUB AND BLADE correctly secured.
ASSEMBLY — INSPECTION
7. Examine the two pitch horns for damage
2-35. Condition and Security — General (paragraph 2-61). Make sure the attaching hardware is
Inspection correctly secured.

2-36. TAIL ROTOR HUB AND BLADE

WARNING ASSEMBLY — REMOVAL

MAKE SURE THAT THE TAIL ROTOR

CONTROLS ARE NOT OPERATED BY SPECIAL TOOLS REQUIRED
ANY PERSONS DURING THE
INSPECTION. INSTALL A PLACARD "DO
NOT OPERATE THE PEDALS" IN THE NUMBER NOMENCLATURE
F L I G H T C O M PA R T M E N T. I F T H E
— Crowfoot, 1 7/8 Inch
P E D A L S A R E O P E R AT E D W H E N A
PERSON WORKS ON THE TAIL ROTOR,
INJURY CAN OCCUR.

MAKE SURE THAT THE TAIL ROTOR WARNING

DOES NOT ROTATE. IF THE TAIL ROTOR
CAN ROTATE, INJURY CAN OCCUR.
MAKE SURE THAT THE TAIL ROTOR
CONTROLS ARE NOT OPERATED BY
NOTE
ANY PERSONS DURING THE
This inspection is to determine if any of the INSPECTION. INSTALL A PLACARD "DO
components of the tail rotor assembly are NOT OPERATE THE PEDALS" IN THE
damaged to the extent that it should be FLIGHT COMPARTMENT IF THE PEDALS
replaced or repaired. This inspection is A R E O P E R ATE D W H E N A P E RS O N
done with the tail rotor assembly installed. WORKS ON THE TAIL ROTOR, INJURY
CAN OCCUR.
1. Examine mast nut (2, Figure 2-10) and lockwire
for damage (paragraph 2-39). Make sure that mast nut
and lockwire are attached correctly.
WARNING
2. Examine flapping stop (7) for damage (paragraph
2-41).
MAKE SURE THAT THE TAIL ROTOR
DOES NOT ROTATE. IF THE TAIL ROTOR
3. Examine the exposed portion of yoke (3) for CAN ROTATE, INJURY CAN OCCUR.
damage (paragraph 2-77).

4. Examine four counterweight supports (4) for NOTE

damage (paragraph 2-57). This procedure is for the removal of the
complete tail rotor assembly from the
5. Examine weight supports (5) for damage gearbox output shaft. To disassemble the
(paragraph 2-70). Examine the security of weight tail rotor hub assembly, refer to paragraph
supports (5). 2-66. To disassemble the blade assembly,

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refer to paragraph 2-56 and paragraph 2-37. TAIL ROTOR HUB AND BLADE
2-60. ASSEMBLY — INSTALLATION

1. Remove the flight control components from the

tail rotor as follows:
MATERIALS REQUIRED

a. Remove lockwire from bolts (15, Figure 1-3). Refer to BHT-ALL-SPM for specifications.
Remove bolts (15) and washers (14) that secure plate
(13) onto crosshead (21). NUMBER NOMENCLATURE

b. Move crosshead (21) inboard far enough to C-104 Corrosion Preventive

expose the machined area on tube assembly (2). Compound, Grade 2

c. Remove cotter pin (17). Use a wrench in the C-405 Lockwire

machined area to hold tube assembly (2) while
C-561 Grease
removing nut (16).

d. Remove washer (18) and plate (13) from tube

assembly (2). SPECIAL TOOLS REQUIRED

e. Disconnect pitch links (23) at pitch horn

assemblies. NUMBER NOMENCLATURE

f. Remove lockwire from bolts (7) and remove — Crowfoot, 1 7/8 Inch
bolts (7) and washers (8).

g. Remove pitch links (23), crosshead (21) and

seal (22) from gearbox shaft (1). WARNING

2. Remove lockwire from mast nut (2, Figure 2-10).

MAKE SURE THAT THE TAIL ROTOR
3. Use the crowfoot to remove mast nut (2). CONTROLS ARE NOT OPERATED BY
ANY PERSONS DURING THE
4. Remove support (5, Figure 1-3). INSPECTION. INSTALL A PLACARD "DO
NOT OPERATE THE PEDALS" IN THE
5. Remove tail rotor blade assembly (1, F L I G H T C O M PA R T M E N T. I F T H E
Figure 2-10). P E D A L S A R E O P E R AT E D W H E N A
PERSON WORKS ON THE TAIL ROTOR,
INJURY CAN OCCUR.
6. Remove spacer (3, Figure 1-3).
MAKE SURE THAT THE TAIL ROTOR
DOES NOT ROTATE. IF THE TAIL ROTOR
CAN ROTATE, INJURY CAN OCCUR.

NOTE
This procedure is for the installation of the
complete tail rotor assembly on the
gearbox output shaft. For the assembly of
the tail rotor hub assembly, refer to
paragraph 2-67.

1. For installation procedures, refer to Chapter 1,

paragraph 1-8 and paragraph 1-9.

ECCN EAR99 16 NOV 2009 Rev. 1 2-47

FOR BEST VALUE, BUY GENUINE BELL PARTS
BHT-206-SI-2054

2-38. TAIL ROTOR HUB AND BLADE a. Examine flapping stop (9) ears for
ASSEMBLY ATTACHING deformation. Make sure that the gaps are within the
COMPONENTS limits shown in Figure 2-36.

2-39. MAST NUT — INSPECTION b. If flapping stop (9) ears are deformed, then the
tail rotor yoke is suspected to have had hard contact
with the flapping stop. Remove the tail rotor yoke and
1. Examine the mast nut (2, Figure 2-10) for the flapping stop from service.
mechanical and corrosion damage. If damage is larger
than damage limits shown on Figure 2-40, replace
2-42. FLAPPING STOP — REPAIR
mast nut. If damage is within limits, repair mast nut.

2-40. MAST NUT — REPAIR NOTE

Refer to the Corrosion Control Guide and
BHT-ALL-SPM for corrosion removal and/
NOTE or repair procedures. These procedures
Refer to the Corrosion Control Guide and may also be used for repair of mechanical
BHT-ALL-SPM for corrosion removal and/ damage.
or repair procedures. These procedures
may also be used for repair of mechanical Ensure applicable damage limits are not
damage. exceeded during completion of repairs.

Ensure applicable damage limits are not 1. If damage to flapping stop (9, Figure 2-10) is
exceeded during completion of repairs. within limits shown on Figure 2-36, repair flapping
stop.
1. If damage to mast nut (2, Figure 2-10) is within
limits shown on Figure 2-40, repair mast nut. 2-43. TAIL ROTOR BLADE ASSEMBLY

2-41. FLAPPING STOP — INSPECTION 2-44. TAIL ROTOR BLADE ASSEMBLY —

DESCRIPTION

The tail rotor blade assembly is made of composite

WARNING materials and has a stainless steel leading edge. The
tail rotor blade assembly consists of a pitch horn and
counterweight supports.
I F T H E S T O P Y I E L D I N D I C AT O R
CLEARANCE IS DECREASED, DISCARD 2-45. TAIL ROTOR BLADE ASSEMBLY —
S TO P Y IE L D IN DI CATO R A ND TA I L REMOVAL
ROTOR YOKE. INSPECT PITCH LINKS
AND PITCH HORNS FOR CONDITION. 1. If tail rotor hub and blade assembly is installed on
INSPECT TAIL ROTOR BLADES FOR helicopter, remove the components of the flight control
DELAMINATION. INSPECT TAILBOOM system from the blade (paragraph 2-36, step 1,
FOR CONDITION IN TAIL ROTOR BLADE substep e and step 1, substep f).
TIP PATH AREA.

1. Examine flapping stop (9, Figure 2-10) for NOTE

mechanical and corrosion damage. If damage is larger
This procedure is for the removal of one tail
than damage limits shown on Figure 2-36, replace the
rotor blade. Use the same procedure to
flapping stop. If damage is within limits, repair flapping
remove the opposite tail rotor blade.
stop.
If the same tail rotor blades are to be
2. Examine flapping stop (9) for evidence of hard installed on the same tail rotor yoke
contact with the tail rotor yoke as follows: assembly, retain and note location of

2-48 Rev. 2 9 JUN 2011 ECCN EAR99

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 BHT-206-SI-2054

balance washers for their installation at the

NOTE
same location.
If the nicks, scratches, or sharp dents are
2. Remove tail rotor blade as follows: less than 0.005 inch (0.127 mm) in depth,
the blade is serviceable after the damage is
polished out.
a. Remove and discard cotter pins (1,
Figure 2-10A).
d. Nicks, scratches, or sharp dents not
exceeding 0.005 inch (0.127 mm) in depth.
b. Remove nuts (2).

NOTE
c. Remove balance washer(s) (3), if installed.
If the dents are not sharp and are not more
d. Remove chamfered washers (4). than 0.010 inch (0.254 mm) in depth, the
blade is serviceable.

e. Remove inboard bolt (6) with chamfered

e. Non-sharp dents not exceeding 0.010 inch
washer (4) and counterweight supports (5 and 7).
(0.254 mm) in depth.

f. Remove outboard bolt (6) with chamfered

washer (4). NOTE
Nicks or scratches in erosion shield (2) are
g. Remove blade (8) from yoke assembly. permitted if they do not penetrate erosion
shield.
h. Remove pitch horn (paragraph 2-60).
2. Examine erosion shield (2). If any damage or
defect penetrates erosion shield, replace the blade.
2-46. TAIL ROTOR BLADE ASSEMBLY —
INSPECTION
3. Examine trailing edge (1). Nicks and notches that
are less than 0.060 inch (1.524 mm) in depth are
permitted after repair. If any damage is more than the
CAUTION required limit after repair, replace the blade.

IF ANY OF THE LIMITS THAT FOLLOW

ARE EXCEEDED, REPLACE THE BLADE. CAUTION
IF THE BLADE IS NOT REPLACED, THE
H E L I C O P T E R C A N N O T O P E R AT E
WITHIN THE CRITICAL FLIGHT SAFETY BALANCE SCREWS (5) ARE BONDED IN
LIMITS. PLACE AND DO NOT REQUIRE TO BE
LOCKWIRED.
1. Examine the abrasion strip (7, Figure 2-11) on the
leading edge. If any of the defects or damage that DO NOT USE A SCREW DRIVER TO
follows are found, replace the blade: VERIFY THE LOOSENESS OF THE
SCREWS. SEALANT MAY GET
DAMAGED AND ALLOW MOISTURE TO
a. Leading edge deformation due to erosion.
ENTER INSIDE THE BLADE.

b. Holes, cracks, or tears. 4. Visually inspect balance screws (5) and balance
weights (4). Make sure that they are not loose. If they
c. Edge voids deeper than 0.250 inch (6.35 mm) are loose, send the blade to a Bell Helicopter
in depth. approved repair facility for repair.

ECCN EAR99 9 JUN 2011 Rev. 2 2-48A/2-48B

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

12
5
11
7

11
10

2 9
1

DETAIL A

6
4
7

1. Cotter pin
2. Nut
3. Balance washer
4. Chamfered washer SEE DETAIL A
5. Counterweight support
6. Bolt 6
5
7. Counterweight support
8. Blade 4
9. Nut 4
10. Washer
3
11. Weight 8
12. Bolt 2
2

CORROSION PREVENTIVE COMPOUND (C-104) 1

1 4
CORROSION PREVENTIVE COMPOUND (C-101) 3 3
2
100 TO 140 IN-LB
1 (11.3 TO 15.82 Nm) 1
150 TO 175 IN-LB 1 2
2 (16.9 TO 19.8 Nm) 2

NOTES
1 Apply a coating of corrosion preventive compound (C-104) to all bolt shanks prior to installation. Do not
apply corrosion preventive compound to bolt threads.

2 Install the nut (9) on the outboard side of the blade only towards the direction of rotation. Install the nut on
the inboard side of the blade only opposite of the direction of rotation.

3 Apply a coating of corrosion preventive compound (C-101) to all bolt heads, washers, nuts, and exposed
threads after installation.

206_SI_2054_0011+

Figure 2-10A. Tail Rotor Blade Assembly — Removal/Installation

ECCN EAR99 9 JUN 2011 Rev. 2 2-49

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BHT-206-SI-2054

Figure 2-11. Blade Assembly (400-016-100) — Inspection and Repair

2-50 Rev. 1 16 NOV 2009 ECCN EAR99

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 BHT-206-SI-2054

repaired in crosshatched area only. Repair of this type

NOTE
damage is limited to 2.0 inches (50.80 mm) in
Blade bolt retention bushings (6) are not diameter. Repair of damage exceeding
field replaceable. If bushing needs to be 1.0 square inch (645.20 mm2) must be accomplished
replaced, send the blade to a Bell by a Bell Helicopter Textron authorized blade repair
Helicopter approved blade repair facility. facility.

5. Examine bushings (6) for corrosion, pitting, g. Replace blade if damage limits are exceeded.
gouges, wear, or other damage.
9. Inspect blade for voids:
6. Repair bushing (6). Maximum bushing inside
diameter after repair is 0.376 inch (9.550 mm). If limit
is exceeded, bushing has to be replaced.
CAUTION
7. If the damage does not exceed 20% of the inside
surface of bushing (6), repair bushing. If limit is
exceeded, replace bushing. ONLY A QUALIFIED INSPECTOR
SHOULD PERFORM THE FOLLOWING
8. Inspect blade skin (3) as follows: INSPECTION.

NOTE NOTE
If fibers of skin are broken or skin is A void is defined as any unbonded area.
penetrated, but core is not damaged, or Many sub-definitions of voids are often
core damage is less than 1.0 square inch used, such as lack of adhesive, gas pocket,
(645.2 mm2), repair skin (paragraph 2-51). misfit, etc. This Service Instruction makes
no distinction among these sub-definitions,
Damage to the core in excess of but groups them under the general term:
1.0 square inch (645.2 mm2), but can be void. Inspect for voids using small steel
enclosed within a 2-inch (50.8-mm) tapping hammer (T75449-2) or equivalent,
diameter circle must be repaired by a Bell on small surfaces.
Helicopter Textron authorized repair facility.

a. Inspect skin (3) for cracks. If cracks are found, NOTE

replace blade. There is no adhesive bonding from the
extreme leading edge of the abrasion
b. Examine the two sides of skin (3) at every bolt strip (7) to 0.050 inch (1.27 mm) aft. This
and bracket installation. If voids do not exist, area will sound hollow, like a void, when
impressions in skin are permitted without repair. tapped.

c. If nicks, scratches, or dents do not break the a. Inspect for voids under abrasion strip (7):
fibers or cause delaminations, they are permitted
without repairs.
(1) Single voids, not in excess of
0.60 square inch (387.10 mm2) in area with a
d. If damage breaks fibers or penetrates skin (3)
maximum chordwise width of 0.20 inch (5.08 mm), are
inboard of station 14.50, replace the blade.
acceptable.
e. Damage outboard of station 14.50 that breaks
the fibers or penetrates skin (3), but does not damage (2) Voids within 0.20 inch (5.08 mm) of each
core (8), may be repaired if damage does not exceed other shall be considered a single void.
2.0 inches (50.8 mm) in diameter.
(3) If total area of voids is in excess of
f. Damage outboard of station 14.50 which 1.0 square inch (645.2 mm2) on each side, the blade
penetrates skin (3) and damages core (8) may be must be replaced.

ECCN EAR99 9 JUN 2011 Rev. 2 2-51

FOR BEST VALUE, BUY GENUINE BELL PARTS
BHT-206-SI-2054

(4) Voids within 0.25 inch (6.35 mm) from the 1. Thoroughly clean the blade, including the
edge of abrasion strip (7) are not permitted. Voids at surfaces of the root end cuff, with a weak solution of
the edge of abrasion are also not permitted. cleaning compound (C-318). Rinse with clear water.

(5) Edge voids less than 0.25 inch (6.35 mm) 2. Cool the blade in a refrigerator for a minimum of
in depth must be repaired. If edge voids exceed 1 hour at a temperature of -1 to 7°C (30 to 45°F).
0.25 inch (6.35 mm) in depth, blade must be replaced.

b. Inspect erosion shield (2) for voids. Voids are 3. Fill the water tank with clean clear water. For best
not acceptable if they are more than 0.50 inch results, the water should be maintained at 60 to 80°C
(12.7 mm) wide chordwise, 1.0 inch (25.4 mm) wide (140 to 175°F) (Figure 2-11A).
spanwise, or closer than 0.50 inch (12.7 mm) to an
edge.

c. Inspect for voids under skin (3): CAUTION

(1) Voids between the skin (3) at trailing DO NOT SUBMERGE THE BLADE IN
edge (1) in excess of 1/4 width of mating surfaces and WATER FOR MORE THAN 2 MINUTES.
3.0 inches (76.2 mm) in length are not acceptable. MAINTAINING THE BLADE IN WATER
FOR MORE THAN 2 MINUTES COULD
(2) Voids between skin (3) and core (8) ALLOW WATER TO ENTER THE BLADE
exceeding 0.70 square inch (451.64 mm2) in area and IF A LEAK PATH IS PRESENT.
0.25 inch (6.35 mm) chordwise width are not
acceptable.
NOTE
(3) Total area of voids exceeding The blade should be left in the heated
1.20 square inches (774.19 mm2) on either side of water for a minimum of 1 minute and a
blade is not acceptable. maximum of 2 minutes.

(4) If there is any delamination between the 4. Wearing protective gloves, place the cool
skin and the plies, replace the blade. blade (1) into the heated water. The blade will float so
it will be necessary to manually submerge the blade.
2-46A. BLADE LEAK CHECK

NOTE
MATERIALS REQUIRED Be careful not to misinterpret random
trapped surface air bubbles as a leak point.
Refer to BHT-ALL-SPM for specifications.
5. Slightly rotate the blade (1) back and forth about
NUMBER NOMENCLATURE
the blade pitch change axis to allow any air trapped on
C-318 Cleaning Compound the blade surfaces to be expelled.

NOTE NOTE

The following inspection (ASB 206-10-165) It may take several seconds before the air
should be performed whenever signs of is forced out through any existing leak path.
delamination/separation are visible at the
root end area of the blade or if excessive 6. With the blade (1) under water, check for air
tail rotor vibrations are reported with no leaks, which will be indicated by a steady stream of
apparent causes. fine bubbles originating from a single point.

2-52 Rev. 2 9 JUN 2011 ECCN EAR99

BUY BELL PARTS, BUY BELL VALUE
 BHT-206-SI-2054

1. Blade
2. Root end cuff 3
3. Leading edge drain hole
2

NOTES
1 Water temperature to be maintained between 60 to 80°C (140 to 175°F).

2 Water tank should be 18 inches (45.7 cm) wide x 36 inches (91.4 cm) long by 18 inches (45.7 cm) deep.
407_MM_64_0010+

Figure 2-11A. Blade Leak Check

ECCN EAR99 9 JUN 2011 Rev. 2 2-52A

FOR BEST VALUE, BUY GENUINE BELL PARTS
BHT-206-SI-2054

7. Slightly rotate the blade (1) back and forth to abrasive paper (C-423). Remove only enough material
allow a thorough inspection of all the blade surfaces. to remove damage.
Pay particular attention to the root end cuff (2) and
around the leading edge drain hole (3). 2. Sand out nicks and scratches to erosion
shield (2) with 180-grit abrasive paper (C-423). Lightly
8. If an air leak is found, contact Product Support abrade painted surfaces surrounding polished areas.
Engineering.
3. Sand out damage area in blade trailing edge (1)
9. If no air leak is found, but the tail rotor assembly with 180-grit abrasive paper (C-423) followed with
has a history of balance change or balance difficulties, 320-grit abrasive paper (C-423). Blend repair out a
additional maintenance is required. Refer to this minimum of 2 inches (50.8 mm) on each side of
chapter for the additional maintenance procedures. damage.

10. If no air leak is found, then the blade (1) is 4. Repair damaged area to blade bolt retention
acceptable for return to service. bushing (6) as follows:

2-47. TAIL ROTOR BLADE ASSEMBLY — a. Sand out damaged area with crocus cloth
REPAIR (C-500) if damage is restricted to a small local area.

2-48. Surface Damage — Repair b. After removal of damaged area, measure

inside diameter of bushing (6). Maximum diameter of
0.376 inch (9.55 mm) is allowed.
MATERIALS REQUIRED
c. If damage is in a small enough area that it can
Refer to BHT-ALL-SPM for specifications. be repaired by local polishing on a maximum of 20% of
inside surface of bushing, repair is permitted.
NUMBER NOMENCLATURE
5. Sand out damaged area in blade skin (3) with
C-423 Abrasive Paper 180-grit abrasive paper (C-423) followed with 320-grit
abrasive paper (C-423). Lightly abrade painted
C-500 Crocus Cloth surfaces surrounding painted area.

NOTE 6. Paint the repaired area (paragraph 2-54).

After tail rotor blade assembly repair has

been accomplished, the tail rotor balance
shall be dynamically checked.

1. Sand out nicks and scratches to abrasion

strip (7, Figure 2-11) with steel wool and 180-grit

2-52B Rev. 2 9 JUN 2011 ECCN EAR99

BUY BELL PARTS, BUY BELL VALUE
 BHT-206-SI-2054

2-49. Edge Voids — Repair 2-49A. Blade Exterior Surface and Leading Edge
Drain Hole — Repair

MATERIALS REQUIRED
MATERIALS REQUIRED
Refer to BHT-ALL-SPM for specifications.
Refer to BHT-ALL-SPM for specifications.
NUMBER NOMENCLATURE
NUMBER NOMENCLATURE
C-309 MEK
C-305 Aliphatic Naphtha
C-317 Adhesive
C-363 Adhesive
C-363 Adhesive
C-423 Abrasive Paper
C-423 Abrasive Paper
C-516 Clean Cloth
C-516 Clean Cloth

1. Repair edge voids under abrasion strip (7, NOTE

Figure 2-11) which do not exceed 0.25 inch (6.35 mm) Repair to the exterior surface of the blade
depth as follows: (ASB 206-10-165) is limited to voids or
missing adhesive, and cracks in the paint in
a. Use a 180-grit abrasive paper (C-423) and the leading edge drain hole or the trailing
remove the paint and primer in an area of 3.0 inches edge surface between the blade root end
(76.2 mm) around the void area. Use a clean cloth block and the blade skin, providing no air
(C-516) moist with MEK (C-309) and remove the leak is found (paragraph 2-46A).
remaining paint and primer in the area.
1. Use 220 grit abrasive paper (C-423) to abrade by
hand the area to be repaired. Do not abrade into the
b. Mix adhesive (C-317) or adhesive (C-363) per
fiberglass.
manufacturer’s instructions.

c. Fill void completely with adhesive using 2. Thoroughly clean the abraded area using
tongue depressor or putty knife. aliphatic naphtha (C-305). Do not allow the aliphatic
naphtha (C-305) to enter the blade. Wipe dry with a
clean cloth (C-516).
d. Smooth adhesive to surrounding surfaces.

3. Apply sufficient adhesive (C-363) to the affected

NOTE area to completely seal the defect.
Adhesive may be cured at room
temperature for 24 hours instead of 4. Cure the adhesive (C-363) per the
applying heat. manufacturer’s instructions.

e. Using heat gun, cure adhesive for 2 hours at

5. Use 220 grit abrasive paper (C-423) to abrade
155 to 165°F (68.3 to 73.8°C). Apply heat locally and
the cured adhesive to obtain a smooth finish.
do not exceed maximum temperature.

f. When adhesive is cured, use a 180-grit 6. Perform a blade leak check (paragraph 2-46A) to
abrasive paper (C-423) and smooth around the repair. make sure the blade does not leak.

g. Paint the repaired area (paragraph 2-54). 7. Paint the repaired area (paragraph 2-54).

ECCN EAR99 9 JUN 2011 Rev. 2 2-53

FOR BEST VALUE, BUY GENUINE BELL PARTS
BHT-206-SI-2054

2-49B. Blade Root End Cuff — Repair 2-51. Damaged Skin with no Core Damage or
Core Damage Limited to 1.0 Square Inch
(645.2 mm²) — Repair

MATERIALS REQUIRED
MATERIALS REQUIRED
Refer to BHT-ALL-SPM for specifications.

NUMBER NOMENCLATURE Refer to BHT-ALL-SPM for specifications.

C-305 Aliphatic Naphtha NUMBER NOMENCLATURE

C-308 Sealant C-309 MEK

C-516 Clean Cloth C-317 Adhesive

C-326 Denatured Alcohol

NOTE C-423 Abrasive Paper

Repair to the blade root end cuff C-426 Masking Tape

(ASB 206-10-165) is limited to voids or
C-516 Clean Cloth
missing adhesive or sealant. Cracks in the
adhesive can be repaired providing no air 299-015-008-127 Skin Patch
leak is found (paragraph 2-46A).

1. Thoroughly clean the area around the defect NOTE

using aliphatic naphtha (C-305). Do not allow the Repair is limited to 2.0 inches (50.8 mm) in
aliphatic naphtha (C-305) to enter the blade. Wipe dry diameter. Patch must cover damage a
with a clean cloth (C-516). minimum of 1.0 inch (25.4 mm) in all
directions.

2. Apply sufficient sealant (C-308) to the affected If damage passes through both skins with
area to completely seal the defect. The sealant core damage less than 1.0 square inch
(C-308) should extend a minimum of 0.250 inch (645.16 mm²), repair by applying skin
patches on both sides.
(6.35 mm) around the defect in all directions.
1. Remove paint and primer from blade around
3. Cure the sealant (C-308) per the manufacturer’s damage for approximately 3.0 inches (76.2 mm) using
instructions. 180-grit abrasive paper (C-423).

2. Remove final traces of paint and primer using a

4. Perform a blade leak check (paragraph 2-46A) to clean cloth (C-516) dampened with MEK (C-309).
make sure the blade does not leak.

NOTE
5. Paint the repaired area (paragraph 2-54).
Outer surface of patch material is marked
with arrow for direction of installation.
2-50. Blade Bolt Retention Bushing —
Replacement 3. Cut patch from skin patch material
299-015-008-127. Trim to a diameter 2.0 inches
(50.8 mm) larger than damaged area (Figure 2-12).
Replacement of blade bolt retention bushings must be
accomplished by a Bell Helicopter Textron authorized 4. Remove peel ply and abrade inner surface of
blade repair facility. patch with 180-grit abrasive paper (C-423).

2-54 Rev. 2 9 JUN 2011 ECCN EAR99

BUY BELL PARTS, BUY BELL VALUE
 BHT-206-SI-2054

206_SI_2054_0071_c01+
Figure 2-12. Skin and Core — Damage Repair

ECCN EAR99 9 JUN 2011 Rev. 2 2-55

FOR BEST VALUE, BUY GENUINE BELL PARTS
BHT-206-SI-2054

5. Clean sanded area of blade and patch with a 2-53. Blade Root End Sealant — Replacement
clean cloth (C-516) dampened with denatured alcohol
(C-326). Repeat with clean cloth (C-516) and alcohol
until rag remains clean after wiping. MATERIALS REQUIRED

6. Use a clean cloth (C-516) and dry the patch and Refer to BHT-ALL-SPM for specifications.
the damaged area of the blade.
NUMBER NOMENCLATURE
7. Mix adhesive (C-317) per manufacturer's
C-306 Toluene
instruction.
C-322 Adhesive
8. Apply adhesive (C-317) to patch and mating
surface of blade. Spread adhesive thoroughly using C-326 Denatured Alcohol
putty knife or tongue depressor to achieve complete
wetting of surfaces. Use sufficient adhesive to fill low C-516 Clean Cloth
areas on blade skin.
1. Clean drain hole (2, Figure 2-13) and bone joints
9. Position patch on blade with arrow pointing in a between root closure (1) and skin (3) with a clean cloth
spanwise direction. Secure patch with 1.0 inch (C-516) or adhesive brush dampened with denatured
(25.4 mm) wide masking tape (C-426). alcohol (C-326) or toluene (C-306).

NOTE 2. Air dry for 30 minutes.

Adhesive (C-317) may be cured at room

3. Mix adhesive (C-322).
temperature for 24 hours instead of
applying heat.
4. Apply a coat of adhesive (C-322) approximately
10. Using heat gun, cure adhesive (C-317) for 2 0.0312 inch (0.79 mm) thick and 0.25 inch (6.35 mm)
hours at 155 to 165°F (68.3 to 73.8°C). Apply heat wide to cleaned bond joints and inside lip of drain
locally and do not exceed maximum temperature. hole (2).

11. Smooth adhesive (C-317) around patch using 5. Cure adhesive (C-322) for 24 hours at room
180-grit abrasive paper (C-423). temperature or use heat gun and cure for 2 hours at
140°F (59.9°C).
2-52. Damaged Skin and Core Exceeding
1.0 Square Inch (645.2 mm²) — Repair 2-54. Repaired Areas of Blade — Refinishing

Repair of core is permitted only in crosshatch area as MATERIALS REQUIRED

illustrated (Figure 2-12). Repair is limited to 2 inches
(50.8 mm) in diameter. Repair of damage exceeding Refer to BHT-ALL-SPM for specifications.
1 square inch (645.16 mm²) must be accomplished by
a Bell Helicopter Textron authorized blade repair NUMBER NOMENCLATURE
facility.
C-204 Epoxy Polyamide
Primer
C-245 Polyurethane Coating
C-305 Aliphatic Naphtha
C-423 Abrasive Paper
C-426 Masking Tape
C-516 Clean Cloth

2-56 Rev. 2 9 JUN 2011 ECCN EAR99

BUY BELL PARTS, BUY BELL VALUE
 BHT-206-SI-2054

Figure 2-13. Blade Root End Sealant — Replacement

ECCN EAR99 9 JUN 2011 Rev. 2 2-57

FOR BEST VALUE, BUY GENUINE BELL PARTS
BHT-206-SI-2054

11. Using stencil P/N 047-796-024-001, stencil the

NOTE
following on both sides of tail rotor blade tip using
Only topcoat paint touch-up repair is lusterless black color No. 37038. The letters shall be
authorized to a maximum of 50% of the 0.250 inch (6.35 mm) high. Spacing between lines
total painted surface of the blade. If more shall be 0.062 inch (1.58 mm).
than 50% of the total painted surface of the
blade requires paint repair, send the blade DO NOT USE
to an approved BHT blade repair facility. FOR HANDLING
HELICOPTER
For paint touch-up repair after a skin
damage repair, the copper conductive
12. Allow blade to dry a minimum of 24 hours before
coating is to be omitted in the repaired
installing on helicopter.
area. If more than 10% per blade side of
copper conductive coating is missing, send
the blade to an approved BHT blade repair 13. Do a static and dynamic balance of the tail rotor
facility. assembly (paragraph 2-5, paragraph 2-6, and
paragraph 2-12).
1. Clean areas to be refinished with aliphatic
naphtha (C-305) and a clean cloth (C-516). 2-54A. TAIL ROTOR BLADE ASSEMBLY —
INSTALLATION
2. Sand areas to be refinished with 320 grit abrasive
paper (C-423).
MATERIALS REQUIRED
3. Remove sanding residue with a clean cloth
(C-516) dampened with aliphatic naphtha (C-305). Refer to BHT-ALL-SPM for specifications.

4. Mask areas to be painted with 1.0 inch (25.4 mm) NUMBER NOMENCLATURE
wide masking tape (C-426) (Figure 2-14).
C-101 Corrosion Preventive
Compound
5. Mix epoxy polyamide primer (C-204) coating
semigloss white and lusterless black polyurethane C-104 Corrosion Preventive
coating (C-245) as per manufacturer’s instructions. Compound

6. Apply one spray coat of epoxy polyamide primer

1. Put the blade (8, Figure 2-10A) in position on the
(C-204). Allow to dry 1 to 8 hours.
yoke. Make sure that the direction of the blade is
correct. Align the blade holes with the yoke pitch
7. Sand primer smooth with 400 grit abrasive paper change bearings.
(C-423).

8. Remove sanding residue with a clean cloth NOTE

(C-516) dampened with aliphatic naphtha (C-305). This procedure is for the installation of one
tail rotor blade. Use the same procedure to
9. Apply two spray coats of polyurethane coating install the opposite tail rotor blade.
(C-245). The color of polyurethane coating (C-245) is
to be selected as per the blade paint scheme The head of the bolts must be installed on
(Figure 2-14). Let dry for a minimum of 30 minutes and the inboard side of the blades.
a maximum of 24 hours between coats.
2. Apply a coat of corrosion preventive compound
10. Apply two spray coats of semigloss white, color (C-104) to the shank of the bolts (6) and to the shank
No. 27925, or lusterless black, color No. 37038, to of the bolts (12) (if removed).
dimensions shown in Figure 2-14. Allow to dry a
minimum of 30 minutes and a maximum of 24 hours 3. Install the bolt (6) through the outboard yoke pitch
between coats. change bearing hole with one chamfered washer (4)

2-58 Rev. 2 9 JUN 2011 ECCN EAR99

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 BHT-206-SI-2054

under the bolt head on the inboard side of the d. Install the other counterweight support (5) on
blade (8). the opposite side of the blade (8).

4. Install one chamfered washer (4) on the other e. Install the chamfered washer (4).
side of the blade (8).
f. Install the balance washers (3) on the inner
5. Install the balance washers (3) on the outer bolt (6) (if they were removed in disassembly).
bolt (6) (if they were removed in disassembly).
g. Install the nuts (2) T .
6. Temporarily install the nut (2).
h. Install the cotter pins (1).
7. Install the counterweight supports (5 and 7) as
8. Apply a coat of corrosion preventive compound
follows:
(C-101) on exposed threads, bolt heads (6), washers
(3 and 4), and nuts (2).
a. If not installed, install the bolt (12), weights
(11), washer (10), and nut (9) T on the counterweight
supports (5 and 7). 9. Apply a coat of corrosion preventive compound
(C-101) on exposed threads, bolt heads (12), washers
(10), weights (11), and nuts (9) (if applicable).
b. Install the counterweight support (7) on the
blade (8). Make sure the pin of the support is in the
proper hole in the blade. 10. Install the pitch horn (paragraph 2-63).

c. Install the inner bolt (6) with one chamfered 11. If a new, repaired, or repainted blade is installed,
washer (4) under the bolt head on the inboard side of do a static and dynamic balance of the tail rotor
the blade (8). assembly (paragraph 2-4 and paragraph 2-12).

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13.5 IN.
(342.9 mm)

9.4 IN.
(238.8 mm)

5.0 IN.
(127 mm)
OMIT FINISH 1.1 IN.
IN THIS AREA (27.9 mm)

FOR HANDLING
HELICOPTER
DO NOT USE
SEMIGLOSS WHITE
2
POLYURETHANE
TOPCOAT (C-245)
NO. 27925 LUSTERLESS BLACK 3.0 IN.
(PER FED-STD-595) POLYURETHANE (76.2 mm)
TOPCOAT (C-245) (5 PLACES)
NO. 37038
(PER FED-STD-595)

NOTES
1. Dimensions in inches. Metric dimensions in millimeters for reference.

2 If lettering is missing or illegible, stencil the following on both sides of tail rotor blade tip. The letters must
be 1/4 inch (6.35 mm) high. Spacing between lines must be 1/16 inch (1.58 mm). Stencil may be procured
through BHT supply center under P/N 047-796-024-001.

3. Apply marking to each side of blade.

DO NOT USE
FOR HANDLING
HELICOPTER

407_MM_64_0014+

Figure 2-14. Blade Paint Scheme — Description

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2-55. TAIL ROTOR BLADE ASSEMBLY may also be used for repair of mechanical
COMPONENTS damage. Ensure applicable damage limits
are not exceeded during completion of
2-56. COUNTERWEIGHT SUPPORT — repairs.
REMOVAL
1. If damage to counterweight supports (5 and 6,
Figure 2-15) is within the limits shown in Figure 2-41,
NOTE repair the damage.
This procedure is for the removal of the two
counterweight supports on one blade. The 2-59. COUNTERWEIGHT SUPPORT —
procedure to remove the two counterweight INSTALLATION
supports on the other blade is the same.

If weights (11, Figure 2-15) are removed MATERIALS REQUIRED

from counterweight supports (5 and 6),
make a note of their position and order. Refer to BHT-ALL-SPM for specifications.

1. Remove counterweight supports (5 and 6) as NUMBER NOMENCLATURE

follows:
C-101 Corrosion Preventive
a. Remove and discard cotter pin (1). Compound

b. Remove nut (2). C-104 Corrosion Preventive

Compound
c. Note the position of balance washer(s) (3) and
chamfered washer (4). 1. If previously removed, install counterweight
supports (5 and 6, Figure 2-15) and as follows:
d. Remove and keep balance washer(s) (3) and
chamfered washer (4). a. If previously removed, install weights (11) and
washer (10) in the same order as noted in paragraph
e. Remove counterweight support (5). 2-56.

f. Remove bolt (8), chamfered washer (7), and b. Apply a coat of corrosion preventive
counterweight support (6). compound (C-104) to the shanks of bolts (8 and 12).

g. Remove nut (9) and washer (10). c. Install bolt (12) and weights (11).

h. Remove bolt (12) and weights (11). d. Install washer (10) and nut (9).

2-57. COUNTERWEIGHT SUPPORT — e. Tighten nut (9) T .

INSPECTION
f. Install counterweight support (6) on the blade.
1. Examine counterweight supports (5 and 6, Make sure the pin of counterweight support is in the
Figure 2-15) for mechanical and corrosion damage. If proper hole in the blade.
damage is larger than damage limits shown in
Figure 2-41, replace supports. g. Install bolt (8) and chamfered washer (7) from
the inboard side of the blade.
2-58. COUNTERWEIGHT SUPPORT — REPAIR
h. Install counterweight support (5) on the blade.
Make sure the pin of counterweight support is in the
NOTE
proper hole in the blade.
Refer to the Corrosion Control Guide and
BHT-ALL-SPM for corrosion removal and/ i. Install chamfered washer (4) and balance
or repair procedures. These procedures washers (3) in the order noted in paragraph 2-56.

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BHT-206-SI-2054

12
5
11
6

11
10
T 1
9

DETAIL A

SEE DETAIL A

2 T 2
8

7
6

100 TO 140 IN-LB

T 1 (11.3 TO 15.82 Nm)
1. Cotter pin
2. Nut
150 TO 175 IN-LB
3. Balance washer T 2 (16.9 TO 19.8 Nm)
4. Chamfered washer
5. Counterweight support
6. Counterweight support
7. Chamfered washer
8. Bolt NOTE
9. Nut Install the nut (9) on the outboard side of the blade
10. Washer only towards the direction of rotation. Install the nut
11. Weight (9) on the inboard side of the blade only opposite of
12. Bolt the direction of rotation.

206_SI_2054_0088_c01+
Figure 2-15. Counterweight Support — Removal and Installation

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 BHT-206-SI-2054

j. Install nut (2) T . than damage limits shown in Figure 2-37, replace
pitch horn.
k. Install cotter pin (1).
2-62. PITCH HORN — REPAIR
l. Apply a coat of corrosion preventive
compound (C-101) to exposed threads, heads of bolts
(8 and 12), chamfered washers (4), balance washers NOTE
(3), washer (10), weights (11), and nuts (2 and 9). Refer to the Corrosion Control Guide and
BHT-ALL-SPM for corrosion removal and/
2-60. PITCH HORN — REMOVAL or repair procedures. These procedures
may also be used for repair of mechanical
damage.
MATERIALS REQUIRED
Ensure applicable damage limits are not
Refer to BHT-ALL-SPM for specifications. exceeded during completion of repairs.

NUMBER NOMENCLATURE 1. If the damage to pitch horn (5, Figure 2-16) is

within the limits shown on Figure 2-37, repair pitch
C-304 Drycleaning Solvent horn (5).

1. If applicable, remove the pitch links. 2-63. PITCH HORN — INSTALLATION

2. Remove and discard cotter pins (1, Figure 2-16).

MATERIALS REQUIRED
3. Remove nuts (2) and washers (3). Refer to BHT-ALL-SPM for specifications.

4. Remove bolts (4) and washers (3). NUMBER NOMENCLATURE

C-101 Corrosion Preventive

5. Remove pitch horn (5).
Compound, Grade 1

6. Use drycleaning solvent (C-304) and a brush and C-104 Corrosion Preventive
clean the mating surface of the blade. Compound, Grade 2

C-204 Epoxy Polyamide

2-61. PITCH HORN — INSPECTION
Primer

NOTE 1. Apply a coat of epoxy polyamide primer (C-204)

Pitch horn bushings are not field to the mating surfaces of pitch horn (5, Figure 2-16)
replaceable. and on the blade. Do not let the primer dry before
installation.
If required, return the part to Bell Helicopter
Textron (BHT) for evaluation and possible 2. Put pitch horn (5) in position on the blade. Align
rework and installation of replacement holes of pitch horn and the blade.
bushing.
3. Apply a coat of corrosion preventive compound
Refer to General Information Letter (IL)
(C-104) to the shanks of bolts (4).
GEN-04-98 for the applicable shipping
information and to obtain a Return Material
Authorization (RMA) number. 4. Install bolts (4) and washers (3). Make sure that
the heads of bolts are on the inboard side of the blade.
1. Examine pitch horn (5, Figure 2-16) for
mechanical and corrosion damage, if damage is larger 5. Install washers (3) and nut (2) T .

ECCN EAR99 9 JUN 2011 Rev. 2 2-61

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Figure 2-16. Pitch Horn — Removal and Installation

2-62 Rev. 1 16 NOV 2009 ECCN EAR99

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 BHT-206-SI-2054

6. Install cotter pins (1) on nuts (2). 2. Remove clamp rings (5) (paragraph 2-73).

7. Apply a coat of corrosion preventive compound 3. Remove flapping bearing (6) (paragraph 2-92).
(C-101) to exposed threads, bolt heads (4), washers
(3), and nuts (2).
2-66A. TAIL ROTOR HUB ASSEMBLY — NON
DESTRUCTIVE INSPECTION
8. Attach the pitch links.
1. Do a Fluorescent Penetrant Inspection (FPI) for
9. Do a dynamic balance of the tail rotor (paragraph the applicable parts shown in Table 2-6A in
2-12). accordance with the instructions given in paragraph
2-66B (BHT-ALL-SPM, Chapter 6).
2-64. TAIL ROTOR HUB ASSEMBLY
2. Discard all parts that fail the FPI criteria.
2-65. TAIL ROTOR HUB ASSEMBLY —
DESCRIPTION
3. Use a gauss meter to make sure that
magnetization of parts is less than 3 gauss anywhere
The tail rotor hub assembly consists of a stainless on the part. Otherwise, demagnetize the part
steel yoke, elastomeric flapping bearings, yoke pitch (BHT-ALL-SPM, Chapter 6).
change bearings, clamp ring, and weight support.

2-66. TAIL ROTOR HUB ASSEMBLY —

DISASSEMBLY

1. Remove weight supports (2, Figure 2-17) from

yoke (7) (paragraph 2-69).

Table 2-6A. Tail Rotor Hub Assembly — Non Destructive Inspection

FIGURE 2-17 FLUORESCENT PENETRANT

NOMENCLATURE
ITEM NUMBER INSPECTION

5 Clamp Ring X

6 Flapping Bearing X

7 Yoke X

2-66B. TAIL ROTOR HUB ASSEMBLY — 3. Do a FPI of the parts in accordance with
FLUORESCENT PENETRANT Table 2-6B and ASTM E1417 (BHT-ALL-SPM,
INSPECTION Chapter 6).

1. Before you perform the Fluorescent Penetrant 4. Following the performance of the FPI, clean, dry,
Inspection (FPI), make sure all parts are clean. preserve, and store the parts as necessary to prevent
Otherwise, refer to paragraph 2-33. contact or corrosion damage (BHT-206L4-MM-2,
Chapter 10).
2. Remove the primer and paint coats
(BHT-ALL-SPM, Chapter 4).

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Table 2-6B. Fluorescent Penetrant Inspection

FIGURE 2-17 NAME PART NUMBER ACCEPTANCE

ITEM NUMBER CRITERIA

5 Clamp Ring 406-012-105-101 No Cracks

427-012-106-101

6 Flapping Bearing 407-312-100-101 No Cracks

7 Yoke 406-012-102-107/-113 No Cracks

2-67. TAIL ROTOR HUB ASSEMBLY — 2-70. WEIGHT SUPPORT — INSPECTION

ASSEMBLY
1. Examine weight supports (2, Figure 2-17) for
1. Install flapping bearing (6, Figure 2-17) in mechanical and corrosion damage. If damage is larger
yoke (7) (paragraph 2-96). than damage limits shown in Figure 2-45, replace
damaged weight supports.
2. Install clamp rings (5) (paragraph 2-76).
2-71. WEIGHT SUPPORT — REPAIR
3. Install weight supports (2) (paragraph 2-72).
NOTE
2-68. TAIL ROTOR HUB ASSEMBLY Refer to the Corrosion Control Guide and
COMPONENTS BHT-ALL-SPM for corrosion removal and/
or repair procedures. These procedures
2-69. WEIGHT SUPPORT — REMOVAL may also be used for repair of mechanical
damage.
1. If balance washers (10 and 11, Figure 2-17) are
Ensure applicable damage limits are not
installed and removal is required, make a note of the
exceeded during completion of repairs.
number and the position of washers (10 and 11).
1. If damage of weight support (2, Figure 2-17) is
2. Remove nut (12). within limits in Figure 2-45, repair damage.

3. Remove washer(s) (10). If washers are 2-72. WEIGHT SUPPORT — INSTALLATION

serviceable, keep them.
MATERIALS REQUIRED
4. Remove washer(s) (11). If washers are
serviceable, keep them. Refer to BHT-ALL-SPM for specifications.

NUMBER NOMENCLATURE
5. Remove bolt (9).
C-101 Corrosion Preventive
6. Remove washer(s) (10). If washers are Compound
serviceable, keep them.
C-104 Corrosion Preventive
Compound
7. Remove lockwire from bolts (1).
C-405 Lockwire
8. Remove bolts (1).
1. Install weight support (2, Figure 2-17) on clamp
9. Remove weight support (2). ring (5) of yoke (7).

2-64 Rev. 2 9 JUN 2011 ECCN EAR99

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Figure 2-17. Tail Rotor Hub Assembly and Weight Support — Disassembly/Assembly

ECCN EAR99 9 JUN 2011 Rev. 2 2-64A/2-64B

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 BHT-206-SI-2054

2. Apply a coat of corrosion preventive compound than damage limits shown in Figure 2-42, replace the
(C-104) to the shanks of bolts (1). damaged clamp ring.

3. Install bolts (1) T . 2-75. CLAMP RING — REPAIR

4. Use lockwire (C-405) and safety bolts (1). NOTE

Refer to the Corrosion Control Guide and
5. Install the components that follow in the same
BHT-ALL-SPM for corrosion removal and/
order as you removed them in paragraph 2-69 as
or repair procedures. These procedures
follows:
may also be used for repair of mechanical
damage.
a. Apply a coat of corrosion preventive
compound (C-104) to the shanks of bolt (9). Ensure applicable damage limits are not
exceeded during completion of repairs.

NOTE
1. If damage to clamp ring (5, Figure 2-17) is within
The head of bolt (9) must face the pitch the limits shown on Figure 2-42, repair damaged
horn when installed. clamp ring.

b. Install bolt (9) and washer(s) (10) with a 2-76. CLAMP RING — INSTALLATION
maximum of three washer(s) under the head of bolt.

NOTE MATERIALS REQUIRED

A maximum of nine washers (10 and/or 11)
Refer to BHT-ALL-SPM for specifications.
in any combination may be installed on
each of weight supports (2). NUMBER NOMENCLATURE

c. Install washers (11). C-104 Corrosion Preventive

Compound, Grade 2
d. Install washer(s) (10).
C-405 Lockwire

e. Install nut (12) T .

1. Apply corrosion preventive compound (C-104) to
6. Apply a coat of corrosion preventive compound the shanks of bolts (3, Figure 2-17).
(C-101) on exposed threads to the heads of bolts (1)
and (9) and to washers (10 and 11) and nut (12). 2. On both sides of yoke (7), use washers (4) and
bolts (3) to install clamp ring (5).
2-73. CLAMP RING — REMOVAL
3. Tight bolts (3).
1. On both sides of yoke (7, Figure 2-17), cut the
lockwire and remove bolts (3) and washers (4). 4. Use lockwire (C-405) and safety bolts (3).

2. Remove clamp ring (5).

2-77. YOKE — INSPECTION

2-74. CLAMP RING — INSPECTION 1. Examine yoke (7, Figure 2-17) for mechanical
and corrosion damage. If damage is larger than
1. Examine clamp ring (5, Figure 2-17) for damage limits shown in Figure 2-34, replace the
mechanical and corrosion damage. If damage is larger damaged yoke.

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2-78. YOKE — REPAIR in Figure 2-18. They will be required to

perform the pitch change bearings
replacement.
NOTE
Refer to the Corrosion Control Guide and
SPECIAL TOOLS REQUIRED
BHT-ALL-SPM for corrosion removal and/
or repair procedures. These procedures
may also be used for repair of mechanical NUMBER NOMENCLATURE
damage.
Workaid No. 1 Support Sleeve
Ensure applicable damage limits are not
exceeded during completion of repairs. Workaid No. 2 Pressing Sleeve

Workaid No. 3 Plate

If damage to yoke (7, Figure 2-17) is within the limits
shown on Figure 2-34, repair the damage Workaid No. 4 Support Plate

— Caliper 1
2-79. YOKE PITCH CHANGE BEARINGS —
INSPECTION — Surface Table

1. Examine the four yoke pitch change bearings for — Dial Indicator With
looseness in the yoke. If any one of the yoke pitch Vertical Mount
change bearings is loose, replace the loose
bearing(s). — Hand Arbor Press

— Load Cell With

2. Examine the four yoke pitch change bearings for Compatible Meter 2
wear. The maximum allowable wear is 0.010 inch
(0.254 mm) axial play (Figure 2-34). If one or more of NOTES:
the yoke pitch change bearings has excessive wear,
1 Must have a minimum precision to the
replace the loose bearing(s).
thousandth.

3. Examine the yoke pitch change bearings for 2 Must be capable of measuring a load of
damage. The maximum permitted damage on the 200 ±2 pounds (889.64 ±0.57 N).
bearing bore is 0.002 inch (0.051 mm) for one fourth of Calibrated load cell and compatible meter
the bearing circumference (Figure 2-34). If one or can be procured through Omega at:
more of the yoke pitch change bearings has excessive
damage, replace the damaged bearing(s). Telephone: 1-800-622-2378
Fax: 1-800-848-4271
Telephone in Mexico: 001-203-359-7803
2-80. PITCH CHANGE BEARINGS — Product Information: www.omega.com
REPLACEMENT

2-81. PITCH CHANGE BEARINGS — TOOLS

DESCRIPTION

2-82. Workaids and Tools

NOTE
The following workaids can be locally
manufactured using the information given

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 BHT-206-SI-2054

Figure 2-18. Workaids

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2-83. Staking Tools (3) The maximum allowable displacement,

resulting from bearing axial clearance, is a maximum
0.180 inch (4.57 mm), total measured at the blade tip.
SPECIAL TOOLS REQUIRED
c. Inspect individual pitch change axial bearing
wear by removing the tail rotor blade assembly. The
NUMBER NOMENCLATURE maximum allowable wear is 0.010 inch (0.254 mm)
axial play.
T101529-131 Staking Tool Kit,
Consisting of: d. If one or more of the pitch change bearings
has excessive wear, replace the loose bearings.
T101529-7 Housing Assembly

T101529-23 Punch and Set 2-85. PITCH CHANGE BEARINGS — REMOVAL

T101529-27 Support
MATERIALS REQUIRED
T101529-29 Shim

T101529-133 Base Assembly Refer to BHT-ALL-SPM for specifications.

T101529-135 Base Assembly NUMBER NOMENCLATURE

T101529-141 Pilot C-423 Abrasive Paper

NOTE:

1 Base assemblies -133 and -135 are SPECIAL TOOLS REQUIRED

supplied with T101529-139 spacer.

NUMBER NOMENCLATURE
2-84. PITCH CHANGE BEARINGS AXIAL —
PLAY CHECK Workaid No. 1 Support Sleeve

1. To determine if the pitch change bearings in the T101529-23 Punch

yoke assembly require replacement, do the following
T101529-141 Pilot
check:

NOTE
NOTE
To minimize change in balance of the
Pitch change bearing axial wear may be
assembly, index mark all removed items so
checked with the yoke assembly installed,
they will be replaced in their original
and the hub and blade assembly retained
position. Taking care to mark all parts may
against the stop.
allow the operator to reinstall the assembly
on the helicopter without doing a static
a. Deflect blade tip by exerting a maximum of balance.
4.0 ounces (113.40 g) of pressure at the blade tip.
1. Remove the tail rotor hub and blade assembly
b. Measure blade tip displacement as follows: from the helicopter (paragraph 2-36).

(1) Place the hub and blade assembly in a 2. Remove tail rotor blades from the hub assembly
horizontal position. (paragraph 2-45).

(2) Place a straight edge up against the tail 3. Refer to BHT-ALL-SPM, Section 9 for bearing
boom and measure the total displacement observed. removal.

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 BHT-206-SI-2054

2-86. PITCH CHANGE BEARINGS —

INSTALLATION
CAUTION
2-87. Required Shims Calculation
BEFORE PRESSING OUT A BEARING
WITH A STEEL OUTER RACE,
CAREFULLY CUT AWAY AND REMOVE SPECIAL TOOLS REQUIRED
ROLL STAKED LIP ON ONE SIDE OF
THE BEARING USING A FLY CUTTER.
DO NOT CUT INTO THE YOKE NUMBER NOMENCLATURE
ASSEMBLY. THE ROLL STAKED LIP
ONLY NEEDS TO BE SCORED WITH T101529-29 Shim
T H E F L Y C U T T E R. T H I S M A Y B E
ACCOMPLISHED BY HAND PRESSURE T101529-133 Base Assembly
ALONE.
T101529-139 Spacer
4. Remove four feathering bearings (4, Figure 2-19)
and steel sleeves (3) (Pre TB 206L-97-192) or
aluminum sleeves (3) (Post TB 206L-97-192) from NOTE
yoke assembly (2). To ensure proper centering of the bearings
into the yoke it may be necessary to install
T101529-29 shims between T101529-139
NOTE
spacer and T101529-133 base assembly
Workaid No. 1 (support sleeve) is to be for the first bearing staking operation.
manufactured using information given in
Figure 2-18. 1. On yoke side “A” (side that has the two data
tags), use a permanent black marker and mark the
5. Place yoke assembly (2, Figure 2-19) on workaid four bearings installation location as shown in
No. 1 (1) as shown. Figure 2-20.

6. Install pilot (6) into punch (5) as shown and press

2. On the bearing outer race, use a permanent black
bearing (4) with sleeve (3) from yoke assembly (2).
marker and mark all four bearings with the number
that will correspond to their installation location in the
7. Strip the paint and the primer on both sides of the yoke.
yoke on the surfaces indicated by Note 1 in
Figure 2-20.
NOTE
8. Inspect the yoke assembly bearing bores for
Table 2-8 is given as an example of
nicks or scratches. Nicks or scratches not exceeding
required shims measurements and
0.002 inch (0.51 mm) in depth are acceptable if
calculation.
polished out with 400 grit abrasive paper (C-423).
Refer to Figure 2-34 for allowable limits.
3. Using a caliper, measure the yoke thickness at all
four bearing locations as indicated by Note 3 on
Figure 2-20. This is dimension “A”. Record this
dimension in Table 2-7.

4. Using a caliper, measure the width of each

bearing ball as shown in Figure 2-20, Detail A. This is
dimension “B”. Record this dimension in Table 2-7.

5. Calculate dimension “C” ((B - A) / 2 = C)) and

record in Table 2-7.

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Table 2-7. Required Shims

DIMENSION
LOCATION 1 LOCATION 2 LOCATION 3 LOCATION 4
INCH (MM)

A
(Yoke thickness)

B
(Bearing width)

C
((B - A)/2=C))

D
(See Figure 2-20)

E
(See Figure 2-20)

F
(D - E = F)

G (1) (2) (3)

(Required shims) (C
- F = G)

Location of shims (4)

NOTES:

1. Dimension “G” (required shims) is to be rounded to the closest thousandth. Refer to the example given in
step 11.

2. If dimension “G” (required shims) is positive, the shims are to be installed on yoke side “B” (no data tags). If
dimension “G” (required shims) is negative, the shims are to be installed on yoke side “A” (with data tags).

3. Each T101529-29 shim is 0.001 inch (0.254 mm) thick.

4. Yoke side “A” is the side that has the data tags. Yoke side “B” is the side that has no data tags. Refer to
Figure 2-20.

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Table 2-8. Required Shims (Example)

DIMENSION
LOCATION 1 LOCATION 2 LOCATION 3 LOCATION 4
INCH (MM)

A 0.501 0.502 0.504 0.504

(Yoke thickness) (12.725) (12.751) (12.802) (12.802)

B 0.631 0.630 0.631 0.632

(Bearing width) (16.028) (16.002) (16.028) (16.053)

C 0.065 0.064 0.0635 0.064

((B - A)/2=C)) (1.651) (1.626) (1.613) (1.626)

D 1.317 1.320 1.319 1.317

(See Figure 2-20) (33.452) (33.528) (33.503) (33.452)

E 1.256 1.254 1.256 1.255

(See Figure 2-20) (31.902) (31.852) (31.902) (31.887)

F 0.061 0.066 0.063 0.062

(D - E = F) (1.549) (1.676) (1.600) (1.575)

G 0.004 -0.002 0.0005 0.002

(Required shims) (0.102) (-0.051) (0.013) (0.051)
(C - F = G)

Location of shims Side “B” Side “A” None Required Side “B“

NOTES:

1. At location No. 1, 0.004 inch (0.102 mm) of shims are required. Since value “G” (shims required) is positive,
the shims will be installed on yoke side “B”. Yoke side “A” will be staked first.

2. At location No. 2, -0.002 inch (-0.051 mm) of shims are required. Since value “G” (shims required) is
negative, the shims will be installed on yoke side “A”. Yoke side “B” will be staked first.

3. At location No. 3, 0.0005 inch (0.013 mm) of shims would be required. Since value “G” is less than 0.001 inch
(0.025 mm) no shims are required. Either yoke side can be staked first.

4. At location No. 4, 0.002 inch (0.051 mm) of shims are required. Since value “G” (shims required) is positive,
the shims will be installed on yoke side “B”. Yoke side “A” will be staked first.

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Figure 2-19. Bearing and Sleeve — Removal

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Figure 2-20. Yoke and Bearing Marking for References

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6. Temporarily install bearing No. 1 with a sleeve in

Example of rounded numbers :
yoke bearing bore No. 1.
Required shims Rounded number
7. Install base assembly (4, Figure 2-21) (with calculated inch (mm) inch (mm)
spacer (5)) on the yoke as shown. 0.0043 0.004
(0.1092) (0.109)
NOTE 0.0025 0.002 or 0.003
Make sure the bearing and the sleeve are (0.0635) (0.063 or 0.064)
fully seated in the base assembly. -0.0037 -0.004
(-0.0939) (-0.094)
8. With hand pressure, firmly hold the base
assembly against the yoke. 12. Repeat step 7 through step 11 for the other three
bearings.
9. Record dimensions “D” and “E” in Table 2-7.
2-88. Bearings Staking
10. Calculate dimension “F” (D - E = F) and record in
Table 2-7.
MATERIALS REQUIRED
NOTE
Refer to BHT-ALL-SPM for specifications.
The required shims will have to be installed
between spacer (5) and base assembly (4) NUMBER NOMENCLATURE
during the first staking operation. The yoke
side that has no shims will be staked first. C-204 Epoxy Polyamide
Primer
NOTE C-305 Aliphatic Naphtha
If dimension “G” (required shims) is
C-309 MEK
positive, shims are to be installed on yoke
side “B” (no data tags). If dimension “G” C-423 Abrasive Paper
(required shims) is negative, shims are to
be installed on yoke side “A” (with data C-500 Crocus Cloth
tags). If dimension “G” is less than
0.001 inch (0.0254 mm), no shim is
required.
SPECIAL TOOLS REQUIRED
11. Calculate dimension “G” (C - F = G) and record in
Table 2-7. This is the thickness of the required shims
to center the bearing in the yoke. Dimension “G” NUMBER NOMENCLATURE
(required shims) is to be rounded to the closest
T101529-7 Housing Assembly
thousandth. See example below.
T101529-29 Shim

T101529-133 Base Assembly

T101529-135 Base Assembly

T101529-139 Spacer

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Figure 2-21. Measurements for Required Shims Calculation

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NOTE
CAUTION
The bearing and sleeve staking is to be
done in two separate operations.
SLEEVE (3, FIGURE 2-22) AND BEARING
(2) ARE TO BE INSERTED BY HAND 5. For first bearing staking operation, refer to
P R E S S U R E O N L Y. F R E E D O M O F Figure 2-22 and proceed as follows:
MOVEMENT IS REQUIRED FOR
PROPER SLEEVE AND BEARING a. Ensure arbor of drill press is perpendicular
LOCATION. IF REQUIRED TO OBTAIN with drill press table. Set speed of drill press to 250 to
SLIP FIT, THE SLEEVE INSIDE 350 RPM.
DIAMETER AND OUTSIDE DIAMETER
MAY BE LIGHTLY POLISHED WITH 400
GRIT ABRASIVE PAPER (C-423) OR b. Install housing assembly (1) in drill press
CROCUS CLOTH (C-500). mandrel and place base assembly (6) on drill press
table.
1. Clean yoke assembly (4) bearing bores with
aliphatic naphtha (C-305) or MEK (C-309). c. Install required shims (7) as calculated and
noted in Table 2-7 between spacer (5) and base
assembly (6).
NOTE
The complete staking operation must be NOTE
completed within 8 hours prior to the primer
Make sure that yoke assembly (4) is
setting up.
installed with the correct side facing up as
determined in paragraph 2-86 and noted in
NOTE Table 2-7.

Unreduced epoxy polyamide primer

(C-204) is properly mixed, however it is not NOTE
thinned for spraying. Mix the primer 1 hour
Make sure that yoke assembly (4) is seated
prior to use to allow it to thicken up slightly.
level on base assembly (6).

NOTE d. Position yoke assembly (4) with bearing (2)

and sleeve (3) on base assembly (6). As an example,
Install new bearings (2) and aluminum
if shims (7) are to be installed on yoke side “B” the first
sleeves (3) (Post TB 206L-97-192) using
staking is to be done on yoke side “A” (data plate side
wet unreduced epoxy polyamide primer
up).
(C-204) on all faying surfaces.

2. Use a cotton swab to apply epoxy polyamide NOTE

primer (C-204) to yoke assembly (4) bearing bore and
Staking requires light pressure only.
sleeve (3) O.D. Insert sleeve in yoke assembly bearing
bore at location 1.
e. Align bearing (2) bore with pilot of housing
assembly (1) and roll stake sleeve (3) in about
3. Use a cotton swab to apply epoxy polyamide 10-second increments (one side only).
primer (C-204) to sleeve (3) I.D. and bearing No. 1 (2)
O.D. Insert bearing No. 1 (2) in sleeve (3) I.D. at
f. After each 10-second increment, inspect for
location No. 1.
correct displacement of sleeve (3) into chamfer edges
of bearing (2) and yoke assembly (4) bore. Maximum
4. Carefully wipe off excess primer to prevent gap between sleeve and yoke chamfer is 0.005 inch
bearing contamination. (0.127 mm) (Figure 2-23, Detail A).

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Figure 2-22. Bearing Staking

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Figure 2-23. Bearing Proof Load (Sheet 1 of 2)

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Figure 2-23. Bearing Proof Load (Sheet 2 of 2)

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g. Remove base assembly (6, Figure 2-22) from setup and equipment can be used if desired
the drill press after the first operation of roll staking is provided that the intent of this check is met.
completed.
1. To ensure that no axial displacement and/or
6. For second bearing staking operation for opposite lateral looseness of bearing ball (9) outer race and/or
side of the bearing, refer to Figure 2-22 and proceed staked sleeve (8) exist, proof load bearing ball (9) to
as follows: 200 pounds (889.64 N), as follows:

a. Place yoke assembly (6) on workaid No. 1

a. Position base assembly (8) on the drill press
(10) with side “A” (data tags) facing up.
table.

NOTE CAUTION
Spacer (5) and shims (7) are not used for
the second staking operation.
MAKE SURE THE LOAD IS NOT APPLIED
ON BEARING BALL (9) OR ON STAKED
b. Position bearing (2) and yoke assembly (4) on
SLEEVE (8).
T101529-135 base assembly (8) with the non-staked
side of sleeve (3) facing up.
b. Without having dial indicator (1) installed,
apply 200 pounds (889.64 N) of load on bearing (9)
NOTE steel outer race.

Staking requires light pressure only. c. Repeat step b for the three other bearings.

c. Align bearing (2) bore with pilot of housing d. Turn yoke assembly (6) with side “B” (no data
assembly (1) and roll stake sleeve (3) in about tags) facing up and install dial indicator (1) as shown in
10-second increments. Figure 2-23. Do a zero on plate (4).

d. After each 10-second increments, inspect for

correct displacement of sleeve (3) into chamfer edges
of bearing (2) and yoke assembly (4) bore. CAUTION

7. Repeat step 5 and step 6 for the three other MAKE SURE THE LOAD IS NOT APPLIED
bearings (2). ON BEARING BALL (9) OR ON STAKED
SLEEVE (8).
2-89. Bearing Proof Load Check After Staking
NOTE
Reapplying pressure on aluminum sleeve
SPECIAL TOOLS REQUIRED (8) may procure desired result. However,
replacement of aluminum sleeve may also
be required.
NUMBER NOMENCLATURE

Workaid No. 1 Support Sleeve e. Apply 200 pounds (889.64 N) of load on

bearing ball (9) steel outer race and verify for any
bearing ball axial displacement. If axial displacement
is observed, re-stake the bearing as required.
NOTE
The setup and equipment shown in f. Make sure that the chamfers on bearing
Figure 2-23 are recommended to perform ball (9) and yoke assembly (6) bore are correctly filled
this proof load check. However, equivalent with staked aluminum sleeve (8).

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g. Make sure that bearing ball (9) has freedom of

movement and that no binding occurs. SPECIAL TOOLS REQUIRED

h. Check for over staking, as follows:

NUMBER NOMENCLATURE
(1) Insert a 6 inch (152 mm) aluminum bar or
tube 0.375 inch (9.525 mm) in bearing ball (9). T101529-7 Shim

T101529-133 Base Assembly

(2) Attach a pull scale to end of tube. Force
required to move the bearing ball shall not exceed T101529-135 Base Assembly
1.0 pound (4.45 N).
T101529-139 Spacer
NOTE
Burnishing may reduce bearing life. 1. Install yoke assembly (1, Figure 2-24) on a
surface table (6) as shown with either side facing up.
i. If force applied to move bearing ball (9)
exceeds 1.0 pound (4.45 N), bearing ball may be
NOTE
loosened by burnishing.
Make sure that base assemblies (4) and
j. With a bolt secured to bearing ball (9) with a supports (5) are installed at the bearing
nut, attach a drill to the bolt shank and spin bearing location that is measured. Base
ball (9) 60 to 100 RPM in repeated 10-second assemblies (4) and supports (5) are used to
increments. adequately support yoke assembly (1) and
to keep bearing (2) aligned during
measurements.
CAUTION 2. With dial indicator (3) installed on a vertical
mount, do a “zero” at bearing location No. 1 on
yoke assembly (1) unpainted area, as shown in
DO NOT ALLOW ASSEMBLY TO Figure 2-24, Detail A.
OVERHEAT TO WHERE IT BECOMES
UNCOMFORTABLE TO TOUCH WITH
3. With dial indicator (3) measure the height of
BARE HANDS.
bearing (2) ball at two locations, 180° apart as shown
k. After each 10-second increment, check if in Figure 2-24, Detail A.
satisfactory force reading has been obtained.
4. Do the average of these two measurements. This
2-90. Bearing Centering Check After Staking is dimension “A” for location No. 1. Record this
dimension in Table 2-9.

MATERIALS REQUIRED 5. Measure dimension “A” for the three other

bearings (2) and record in Table 2-9.
Refer to BHT-ALL-SPM for specifications.
6. Turn yoke assembly (1) on the other side and
NUMBER NOMENCLATURE repeat step 2 through step 5.
C-204 Epoxy Polyamide
Primer 7. Make sure that dimension “A” and dimension “B”
are within 0.010 inch (0.254 mm) with yoke
C-245 1 Polyurethane Coating assembly (1) surface.

NOTE: 8. Refinish bare metal areas of yoke assembly (1)

with epoxy polyamide primer (C-204) and
1 Use color code 36440 per FED-STD-595.
polyurethane coating (C-245).

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Table 2-9. Bearing Centering Measurements

BEARING
NO. 1 NO. 2 NO. 3 NO. 4
LOCATION

Dimension “A”

Dimension “B”

NOTE:

Dimension “A” and dimension “B” must be within 0.010 inch (0.254 mm) with the yoke surface. If this 0.010 inch
(0.254 mm) maximum off center dimension is not respected an out of track condition of the tail rotor blades may
exist resulting in vibrations.

2-91. Pitch Change Bearing — Installation 2-93. FLAPPING BEARING SPLINED TRUNNION
— INSPECTION
1. Reassemble tail rotor hub and blades (paragraph
2-3). 1. Examine the splined union of the flapping bearing
for mechanical and corrosion damage. If the damage
2. Perform a static balance of the tail rotor hub and is larger than the damage limits as shown in
blade assembly (paragraph 2-5 and paragraph 2-6). Figure 2-27, replace the damaged flapping bearing.

3. Reinstall assembly on the helicopter (paragraph 2-94. FLAPPING BEARING SPLINED TRUNNION
2-37). — REPAIR

1. If the damage to the flapping bearing splined

2-92. FLAPPING BEARING — REMOVAL
trunnion is within limits shown in Figure 2-27, repair
the damage.

SPECIAL TOOLS REQUIRED

2-95. FLAPPING BEARING ELASTOMER —
INSPECTION
NUMBER NOMENCLATURE
1. Examine the elastomer and shims of the flapping
— Arbor Press bearing for damage. If the damage is larger than the
damage limits shown in Figure 2-27, replace the
Item No. 1 Workaid flapping bearing. Do the steps that follow:

Item No. 2 Workaid

a. Examine each shim edge for cracks in the
T101750-101 Flapping Bearing Tool elastomer. If cracks are found in the elastomer,
replace the flapping bearing.

1. Install flapping bearing tool T101750-101 on b. Examine shims that have contacted other
flapping bearing, using workaid No. 1 and workaid shims, the trunnion, or the outer races of the flapping
No. 2. Refer to Figure 2-25 for workaid dimensions. bearing. Contact between the shims and other metal
parts of the flapping bearing will show as fretting or the
2. Put the yoke in position on an arbor press and elastomer will have worn away. If this condition exists,
remove flapping bearing as shown in Figure 2-26. replace the flapping bearing.

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Figure 2-24. Bearing Centering Check

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Figure 2-25. Workaid Item No. 1 and No. 2

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Figure 2-26. Flapping Bearing — Removal

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DIA. G E

B B
A
OUTER MEMBER
SHIMS C
ELASTOMER
D

F
ELASTOMER
D

THE CORRECT NUMBER OF SHIMS

ARE NOT SHOWN FOR CLARITY
(MEASURE WITH A 0.005 INCH

0.2
FEELER GAUGE)
DAMAGE DEPTH

REPLACE
0.1
SERVICEABLE

20 40 60 80 100 120 140 160 180 200

DAMAGE ARC (DEGREES)
ELASTOMER SHEETING/EXTRUSION

407CRO_64_0013_c01+

Figure 2-27. Flapping Bearing Elastomer — Inspection and Repair (Sheet 1 of 3)

2-86 Rev. 2 9 JUN 2011 ECCN EAR99

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FLAPPING BEARING (407-312-100)

MATERIAL: STAINLESS STEEL AND ELASTOMER

REF INSPECTION
NO. CHARACTERISTIC LIMIT
LTR METHOD

1. A Mechanical/corrosion Measure 0.005 inch (0.127 mm)

damage maximum.

2. A Maximum area per Measure 0.050 square inch

full depth repair (32.260 mm ²).

3. A Number of repairs Visual One.

4. B Mechanical/corrosion Measure 0.010 inch (0.254 mm)

damage maximum.

5. B Maximum area per Measure 0.150 square inch

full depth repair (96.780 mm ²2).

6. B Number of repairs Visual Two per segment.

7. A Edge chamfer to Measure 0.010 inch (0.254 mm) x 45°.

remove damage

8. B Edge chamfer to Measure 0.020 inch (0.508 mm) x 45°.

remove damage

9. Cracks None permitted.

10. C Chafing shims Visual No chafing permitted. 2

11. C Cracked shims Visual None permitted.

12. D Elastomer separation, Visual Local defect permitted. 4

cracks or tears

13. D Elastomer voids Visual/measure 5

14. D Elastomer sheeting Visual/measure 6

or extrusion

15. E Spline over pin diameter Measure 1.1454 inch (29.0932 mm)
(pin diameter 0.054 inch maximum diameter.
(1.372 mm))

16. E Mechanical Visual/measure 0.005 inch (0.127 mm) maximum.

damage Depth - 1/3 of a spline.
Length - 1/2 of a spline.
Number - three splines.

17. E Corrosion damage Visual None permitted.

18. F Maximum/minimum length Measure 3.730 inches (94.74 mm) minimum 7

to 3.812 inches (96.82 mm) maximum.

19. G Diameter Measure 1.624 inches (41.2496 mm) minimum.

407_CRO_64_0014_c01+

Figure 2-27. Flapping Bearing Elastomer — Inspection and Repair (Sheet 2 of 3)

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NOTES
1. Damage reference areas:
A

2 Chafing will occur in areas where the elastomer is missing and will result in clean or fretted
surfaces on two adjacent shims, outer housing, or inner member.
3 No mechanical or corrosion damage permitted in this area.

4 If separation, cracks or tears are found on 360° on the two sides of the elastomer,
replace the flapping bearing.

5 A void is an area where the elastomer is missing and you can easily insert a 0.015 inch
(0.381 mm) thickness gauge without deflection of the flapping bearing. Replace the flapping
bearing if the void is equal to or more than the conditions that follow:

a. The total depth of the void is more than 0.25 inch

(6.35 mm). The total depth is the sum of the depths of
the void from the two sides at the same location in a
layer.

b. The total length of the void is more than 45°

of the elastomer arc.

6 Elastomer sheeting or extrusion is elastomer that extends after the edge of the shim.
Measure the maximum extension and arc (in degrees) of the damaged area. Compare
the dimension to the elastomer sheeting/extrusion graph.

7 Only when flapping bearing 407-312-100-101 is used in conjunction with clamp ring
427-012-106-101, minimum length can be reduced to 3.650 inches (62.71 mm).

407CRO_64_0015_c01+

Figure 2-27. Flapping Bearing Elastomer — Inspection and Repair (Sheet 3 of 3)

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c. Examine the elastomer for separation or yoke and the outer race of the elastomer. Do not let
cracks. Some damage is acceptable if it does not the primer dry before installation. Make sure that the
affect the operation of the flapping bearing. Replace primer does not touch the elastomer.
flapping bearing if separations or cracks in the
elastomer exceed the limits shown in Figure 2-27. 3. Put the yoke in position on an arbor press and
install flapping bearing, as shown in Figure 2-28.
d. Examine the elastomer for sheeting of
extrusion between the shims. If any layer shows
2-97. TAIL ROTOR PITCH CHANGE
extrusion to more than 15° of circumference, replace
the flapping bearing. MECHANISM

2-96. FLAPPING BEARING — INSTALLATION 2-98. TAIL ROTOR PITCH CONTROL TUBE

The tail rotor pitch control tube assembly (2, Figure

1-3) is the internal part of the pitch change
MATERIALS REQUIRED
mechanism. The tail rotor control tube is inside the tail
rotor gearbox output shaft, on the left-hand side. It
Refer to BHT-ALL-SPM for specifications.
goes through the tail rotor gearbox (2, Figure 1-1) and
NUMBER NOMENCLATURE ends at the trunnion assembly (6, Figure 1-2), inside
the trunnion cap assembly (7).
C-204 Epoxy Polyamide
Primer The end of the tail rotor control tube assembly (2,
Figure 1-3) on the right-hand side of the tail rotor
gearbox (2, Figure 1-1) has a sleeve (1, Figure 2-29)
installed on it. The sleeve has two functions:
SPECIAL TOOLS REQUIRED
• The sleeve is a wide inner race for the pitch
NUMBER NOMENCLATURE change roller bearings (Figure 2-29). This
function permits tail rotor control tube
— Arbor Press movement in the tail rotor gearbox; and

Item No. 1 Workaid • The sleeve is part of an air vent system

(Figure 2-29). The air vent system prevents air
Item No. 2 Workaid compression or spongy control feel created by
the tail rotor gearbox boot when the tail rotor
T101750-101 Flapping Bearing Tool blade pitch is changed. When the boot is
compressed, air can freely flow through the
hole in the sleeve into the hollow tail rotor
control tube. The air flow will then exit near the
CAUTION cross head. When the boot is extended, the
opposite flow occurs.

M A K E S U R E T H AT T H E E P O X Y 2-99. Tail Rotor Pitch Control Tube — Removal

POLYAMIDE PRIMER (C-204) DOES NOT
TOUCH THE ELASTOMER OF THE
1. Remove the tail boom fin assembly.
F L A P P I N G B E A R I N G, O R T H E
ELASTOMER WILL BE DAMAGED.
2. Remove the pitch change mechanism. Refer to
1. Install flapping bearing tool T101750-101 on BHT-206L-CR&O and the following instructions:
flapping bearing, using workaid No. 1 and workaid
No. 2 (Figure 2-28). a. Remove driver plate (13, Figure 1-3) and pitch
links (23) (paragraph 2-36).
2. Apply a coat of wet epoxy polyamide primer
(C-204) on the mating surfaces of the holes in the b. Remove crosshead (21).

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Figure 2-28. Flapping Bearing Elastomer — Installation

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Figure 2-29. Tail Rotor Control Tube and Sleeve Vent

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2-102. PITCH LINK ASSEMBLY

NOTE
Only remove sleeve (1, Figure 2-29) from 2-103. Pitch Link Assembly — Removal
control tube (2) to align the vent hole or to
replace it.
1. Remove bolt (7, Figure 1-3) and washer (8) from
tail rotor pitch horn assembly (24).
c. Pull control tube (2) out of the tail rotor
gearbox from housing assembly (3) to remove.
2. Remove nut (20), washers (12), and bolt (11)
from crosshead (21). Remove pitch link (23).
2-100. Tail Rotor Pitch Control Tube —
Inspection and Repair
2-104. Pitch Link Assembly — Inspection and
Repair

MATERIALS REQUIRED
MATERIALS REQUIRED
Refer to BHT-ALL-SPM for specifications.
Refer to BHT-ALL-SPM for specifications.
NUMBER NOMENCLATURE

C-108 Cadmium Plating NUMBER NOMENCLATURE

Solution C-100 Chemical Film Material
C-304 Drycleaning Solvent C-423 Abrasive Paper
C-423 Abrasive Paper
1. Examine pitch link (23, Figure 1-3) for damage.
C-500 Crocus Cloth
Refer to Figure 2-39 for damage limits. Replace pitch
link (23, Figure 1-3) if the damage is more than the
1. Clean control tube (2, Figure 2-29) with limits shown.
drycleaning solvent (C-304) and a clean cloth.
2. Remove damage that you can repair with 400 grit
abrasive paper (C-423).
2. Examine control tube (2) for damage. Refer to
Figure 2-48 for damage limits.
3. Apply chemical film material (C-100) to the
repaired areas. Let the chemical film material (C-100)
3. Examine sleeve (1) for damage. Replace sleeve stay on pitch link (23) for approximately 1 minute.
if damage is found. Make sure the sleeve vent hole is Flush pitch link (23) with clean water, and air dry.
aligned with the control tube vent hole.

2-105. Pitch Link Assembly — Installation

4. Remove damage that you can repair with 400 grit
abrasive paper (C-423). Polish the repaired area with
crocus cloth (C-500).
MATERIALS REQUIRED

5. Apply cadmium plating solution (C-108) to the Refer to BHT-ALL-SPM for specifications.
repaired areas that were originally cadmium plated.
NUMBER NOMENCLATURE

2-101. Tail Rotor Control Tube — Installation C-405 Lockwire

1. Refer to installation of tail rotor pitch change 1. Put pitch link (23, Figure 1-3) between pitch
mechanism in Chapter 1, paragraph 1-9. horn assembly (24) and crosshead (21).

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2. Install washer (8) and bolt (7) T that hold the 2. Examine driver plate (13) for cracks, corrosion,
pitch link (23) in pitch horn (24). Safety bolt with and other damage. Refer to Figure 2-43 for damage
lockwire (C-405). limits.

3. Remove the damage that you can repair with 400

NOTE grit abrasive paper (C-423).
Make sure bolt head (11) is on the leading
side of the crosshead. The bolts must be 4. Apply a layer of epoxy polyamide primer (C-204)
installed with the head in the direction of to the repaired areas that were painted.
rotation.
2-109. Driver Plate — Installation
3. Install bolt (11), washers (12), and nut (20) T .
Safety nut (20) with cotter pin.
MATERIALS REQUIRED
2-106. DRIVER PLATE
Refer to BHT-ALL-SPM for specifications.

2-107. Driver Plate — Removal NUMBER NOMENCLATURE

C-405 Lockwire
1. Remove bolts (15, Figure 1-3) and washers (14)
and move crosshead (21) far enough to expose the
machined area on tube assembly (2). 1. Put driver plate (13, Figure 1-3) with the recess
facing outboard on tube assembly (2).

2. Use a wrench in the machined area to hold tube

assembly (2) while removing nut (16). 2. Install washer (18) and nut (16). Use a wrench to
hold tube assembly (2) at the machined area and
torque nut (16) T . Secure with cotter pin (17).
3. Remove washer (18) and driver plate (13) from
tube assembly (2).
3. Move crosshead (21) outboard toward driver
plate (13).
2-108. Driver Plate — Inspection and Repair
4. Install washers (14) and bolts (15) T . Secure
with lockwire (C-405).
MATERIALS REQUIRED
2-110. CROSSHEAD
Refer to BHT-ALL-SPM for specifications.

NUMBER NOMENCLATURE 2-111. Crosshead — Removal

C-204 Epoxy Polyamide

1. Remove driver plate (13, Figure 1-3) (paragraph
Primer
2-107).
C-304 Drycleaning Solvent
2. Remove nut (20), washers (12), and bolts (11)
C-423 Abrasive Paper
from crosshead (21) and pitch link (23).

1. Clean driver plate (13, Figure 1-3) with 3. Move crosshead (21) and sliding seal (22)
drycleaning solvent (C-304). Use a non-metallic bristle outboard until disengagement from output shaft (5,
brush on dirt that is difficult to remove. Figure 1-1).

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2-112. Crosshead — Inspection and Repair 4. Install driver plate (13, Figure 1-3) (paragraph
2-109).

MATERIALS REQUIRED NOTE

Refer to BHT-ALL-SPM for specifications. Make sure bolt head (11) is on the leading
side of the crosshead. The bolts must be
NUMBER NOMENCLATURE installed with the head in the direction of
rotation.
C-204 Epoxy Polyamide
Primer 5. Put pitch link (23) in the horn on crosshead (21).
Install bolt (11), washers (12), and nut (20) T . Safety
C-304 Drycleaning Solvent nut with cotter pin (19).
C-423 Abrasive Paper
2-114. TAIL ROTOR GEARBOX

1. Clean crosshead (21, Figure 1-3) with 2-115. TAIL ROTOR GEARBOX — REMOVAL
drycleaning solvent (C-304). Use a non-metallic bristle AND INSTALLATION
brush on dirt that is difficult to remove.
For the removal and installation of the tail rotor
2. Examine crosshead (21) for cracks, corrosion, gearbox, refer to the BHT-206L4-MM.
and other damage. Refer to Figure 2-35 for damage
limits. 2-116. TAIL ROTOR GEARBOX —
DISASSEMBLY/ASSEMBLY
3. Remove the damage that you can repair with 400
grit abrasive paper (C-423). For the disassembly, assembly, cleaning, inspecting,
and overhauling of the tail rotor gearbox assembly,
refer to the instructions provided in the
4. Apply a layer of epoxy polyamide primer (C-204) BHT-206L-CR&O, except for the output shaft damage
to the repaired areas that were painted. limits and the backlash check.

2-113. Crosshead — Installation 2-117. OUTPUT SHAFT — INSPECTION

1. Inspect output shaft for damage. Refer to

Figure 2-30 through Figure 2-33 for output shaft
MATERIALS REQUIRED
damaged limits.
Refer to BHT-ALL-SPM for specifications.
2-118. TAIL ROTOR GEARBOX — BACKLASH
NUMBER NOMENCLATURE CHECK

C-001 Grease 1. Refer to the installation of tail rotor gearbox, in

Chapter 1, paragraph 1-6.
1. Put sliding seal (22, Figure 1-3) on the tail rotor
gearbox output shaft. 2-119. WEAR AND DAMAGE LIMITS

Refer to Figure 2-30 through Figure 2-54 for maximum

2. Apply a layer of grease (C-001) on the splines of
wear and damage limits for parts included in this kit.
crosshead (21).
For existing parts not included in this kit, refer to
BHT-206L-CR&O. Parts, components, or assemblies
3. Put crosshead (21) on the tail rotor gearbox found worn or defective beyond repairable limits shall
output shaft. Make sure the lips of sliding seal (22) are be scrapped. Inspect parts dimensionally and replace
in the groove in the crosshead. parts that do not fall within inspection limits.

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Figure 2-30. Output Shaft (206-040-949) — Damage Limits (Sheet 1 of 2)

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ITEM DESCRIPTION TYPE OF DAMAGE LIMIT

E GEAR SEAT MECHANICAL NICKS, DENTS, SCRATCHES

0.005 IN. (0.127 mm) DEEP, 0.50 IN.
(12.7 mm) LONG 1.0 IN. (25.40 mm)
MIN. SPACING REWORK
ONLY TO REMOVE ANY RAISED
MATERIAL FLUSH WITH
SURROUNDING SURFACE

F THREADED CORROSION/ NONE ALLOWED

HOLES MECHANICAL

G WEAR SLEEVE CORROSION LIGHT, SUPERFICIAL REMOVABLE

SEAT BY HAND POLISHING WITH FINE
STEEL WOOL OR SCOTCH BRITE

MECHANICAL FINE AXIAL SCRATCHES

0.001 IN. (0.025 mm) DEEP

H SEAL CONTACT CORROSION/ 0.005 IN. (0.127 mm) DEEP LOCAL

AREA & MECHANICAL CLEANUP, ONE AREA PER
TAPERED 1.0 IN. (25.40 mm) OF DIAMETER
SECTION

J O.D. CORROSION/ 0.010 IN. (0.254 mm) DEEP LOCAL

MECHANICAL CLEANUP, THREE AREAS PER
1.0 IN. (25.40 mm) OF DIAMETER

K END SURFACES, CORROSION/ 0.010 IN. (0.254 mm) DEEP LOCAL

SLOTS, SHOULDER MECHANICAL CLEANUP, 25% OF ANY SURFACE.
OUTER DIAS REWORK MECHANICAL DAMAGE
ONLY TO REMOVE RAISED
MATERIAL

L INSIDE DIA CORROSION CLEANUP TO 0.695 IN. (17.653 mm)

MAX DIA BY HONING OR SIMILAR
METHOD WITH UNIFORM MATERIAL
REMOVAL AROUND DIAMETER

M INSIDE DIA, CORROSION/ 0.005 IN. (0.127 mm) DEEP LOCAL

TAPERED MECHANICAL CLEANUP
SECTION

NOTES

1. Inspect shaft by magnetic particle inspection method for cracks.

Indications of cracks shall be cause for rejection.
2. Corrosion pitting must be completely removed within allowable cleanup limits.
3. Surface finish of reworked areas to be 63 RHR. Blend repair areas with
0.50 inch (12.7 mm) minimum radius.

206_SI_2054_0044

Figure 2-30. Output Shaft (206-040-949) — Damage Limits (Sheet 2 of 2)

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Figure 2-31. Output Shaft (206-040-949) — Wear Limits

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Figure 2-32. Output Shaft (206-040-949) — Runout Limits

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Figure 2-33. Output Shaft (206-040-949) — Finish Requirements

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Figure 2-34. Yoke — Inspection and Repair (Sheet 1 of 2)

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See Figure 2-36 inspection of support to determine if yoke flexure has yielded.
If support has yielded, remove yoke from service.

206_SI_2054_0079_c01

Figure 2-34. Yoke — Inspection and Repair (Sheet 2 of 2)

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Figure 2-35. Crosshead (407-012-105) — Damage Limits

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Figure 2-36. Support (206-011-752) — Damage Limits

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Figure 2-37. Pitch Horn Assembly (406-012-108) — Damage Limits

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Figure 2-38. Rod Assembly (206-011-751) — Damage Limits

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Figure 2-39. Pitch Link (406-312-103) — Damage Limits

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Figure 2-40. Nut (406-012-113) — Damage Limits

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Figure 2-41. Counterweight Support (206-011-750) — Damage Limits

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Figure 2-42. Clamp Ring (406-012-105 and 427-012-106) — Damage Limits

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Figure 2-43. Driver Plate (406-012-104) — Damage Limits

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Figure 2-44. Spacer (406-012-110) — Damage Limits

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Figure 2-45. Weight Support (406-012-107) — Damage Limits

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Figure 2-46. Lever Assembly (206-011-741) — Damage Limits

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Figure 2-47. Idler Assembly (406-012-127) — Damage Limits

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Figure 2-48. Control Tube Assembly (406-012-118) — Damage Limits

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Figure 2-49. Support Assembly (206-001-825) — Damage Limits

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Figure 2-50. Bellcrank Assembly (206-001-824) — Damage Limits

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Figure 2-51. Link Assembly (206-001-823) — Damage Limits

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Figure 2-52. Idler Assembly (206-001-822) — Damage Limits

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Figure 2-53. Bellcrank Assembly (206-001-821) — Damage Limits

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Figure 2-54. Bellcrank Assembly (206-001-820) — Damage Limits

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2-120. SCHEDULED INSPECTION designed to ensure continuing airworthiness of the

helicopter. Example: 100 hours and annual inspection.
Inspect helicopter each 100 hours, 300 hours, and
NOTE 1 calendar year of operation to ensure airworthiness.
For airworthiness limitations, refer to the
BHT-206L4-MM, Chapter 4. 2-121. 100 HOURS AND ANNUAL

Scheduled inspections are recurring actions at

designated operating hours or calendar intervals

100 HOURS AND ANNUAL

DATA
INSPECTION TASK DESCRIPTION MECH INITIAL
REFERENCE

FORWARD FUSELAGE

— Inspect.

1. Check minimum friction on antitorque control system. Readjust as

necessary.

AFT FUSELAGE/TAILBOOM AREA

— Inspect.

2. Inspect tail rotor controls for damage and security of attachment.

3. Inspect tail rotor control tube bearing for binding or worn condition.

4. Inspect tail rotor lever, idler, and attached control rod for condition
and security.

5. Inspect boot for cuts, tears, deterioration, and security.

6. Inspect tail rotor retaining nut for condition and security.

7. Apply full left pedal. Check tail rotor pitch change tube for corrosion,
leakage condition, and security.

8. Inspect seal on tail rotor crosshead for cuts, tears, deterioration,

security, and evidence of "rolling under".

9. Remove fairing and inspect tail rotor pitch control mechanism and
gearbox for damage, excessive bearing wear, and security. Inspect boot
for deterioration and security.

10. Inspect tail rotor pitch change link spherical bearings for excessive
wear.
11. Inspect tail rotor pitch change bearings in tail rotor yoke for
excessive wear. Refer to Figure 2-34.

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100 HOURS AND ANNUAL (CONT)

DATA
INSPECTION TASK DESCRIPTION MECH INITIAL
REFERENCE

TAIL ROTOR HUB AND BLADE ASSEMBLY

— Perform serviceability check.

12. Inspect tail rotor hub and blade assembly for damage, cracks, and
wear.

13. Check each tail rotor blade for serviceability as follows:

a. Blade for nicks, dents, and scratches.

b. Visually inspect balance screws and weights for looseness.

c. Condition of sealant between mating surfaces.

d. Inspect for delamination and voids.

e. Check for corrosion around mounting bolts, pitch change
bushings, and pitch horn attachment area.

14. Clean tail rotor blades to maintain improved visibility.

15. Tail rotor flapping bearing, visually inspect (without disassembly) for
evidence of cracked shims, tears, elastomer separation, shims touching,
voids in elastomer or elastomer sheeting, or extrusion. Refer to
Figure 2-27 for allowable limits.

ELECTRICAL

— Electrical inspection.

16. Perform lamp and self-test.

17. Perform rigging mode test.

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SCHEDULED INSPECTIONS

2-122. 300-HOUR INSPECTION

DATA
INSPECTION TASK DESCRIPTION MECH INITIAL
REFERENCE

GENERAL

1. Perform 100 hour scheduled inspection.

TAIL ROTOR HUB AND BLADE ASSEMBLY

1. Do a torque check of the bolts (60 to 80 inch-pounds (6.7 to 9 Nm))

that attach the tail rotor pitch link assemblies to the tail rotor pitch horns.
Reinstall lockwire. Refer to the tail rotor pitch change mechanism
installation (Chapter 1).

2. Do a torque check of the tail rotor assembly mast nut 560 to

580 inch-pounds (64 to 65 Nm).

3. Do a torque check of the tail rotor gearbox retaining nuts 50 to

70 inch-pounds (5.65 to 7.91 Nm).

4. Check dynamic balance of tail rotor hub and blade assembly.

5. Inspect tail rotor blade(s) (ASB 206-10-165) for evidence of

separation between skin plies and root end at trailing edge using a 10X
magnifying glass. If cracks are found, remove the tail rotor blade and do a
blade leak check (paragraph 2-46A).

ELECTRICAL

1. Perform altimeter data test.

2-124 Rev. 2 9 JUN 2011 ECCN EAR99

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2-123. SPECIAL INSPECTIONS Special inspections are accomplished as required, in

accordance with Table 2-10.
A special inspection is of a temporary nature or occurs
at a special interval that is not consistent with the
scheduled inspection.

Table 2-10. Signature Sheet for Special Inspection

DATE: __________________W.O. ______________________

FACILITY: _________________
__________________________

HELICOPTER S/N: __________

__________________________

REGISTRY NO.: ____________

__________________________

TOTAL TIME:_________________________________________

SIGNATURE:_______________
__________________________

COMPONENT INSPECTION SCHEDULE

HOURS AFTER INITIAL INSTALLATION SIGNATURE

1 TO 5 HOURS 10 TO 25 HOURS MECH OTHER

Tail Rotor Gearbox X 1

Torque Check

Tail Rotor Hub Mast Nut X 2

Torque Check

NOTES:

1 Torque check must be repeated every 10 to 25 hours until the torque is stabilized. After the torque has
stabilized, repeat the torque check every 300 flight hours (300-hour inspection).

2 Torque check must be repeated every 1 to 5 hours until torque is stabilized. After the torque has stabilized,
repeat the torque check every 300 flight hours (300-hour inspection).

2-124. DELETED

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2-125. 3000 HOURS OF COMPONENT

OPERATION

DATA
INSPECTION TASK DESCRIPTION MECH INITIAL
REFERENCE

TAIL ROTOR GEARBOX ASSEMBLY

1. For inspection requirements, refer to the BHT-206L4-MM, Chapter 5,
3000 hours of component operation.

2. Inspect tail rotor output shaft for damage and wear, refer to
Figure 2-30 to Figure 2-33 for damage and wear limits.

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2-126. OPERATION IN A CORROSIVE

ATMOSPHERE

DATA
INSPECTION TASK DESCRIPTION MECH INITIAL
REFERENCE

TAIL ROTOR HUB AND BLADE ASSEMBLY

- Preventive maintenance.

NOTES:

1. For repair of defects such as corrosion, nicks, scratches, and in some

instances, blistering, refer to paragraph 2-47.

2. For inspection and repair limits applicable to tail rotor hub, blade and
controls components, refer to paragraph 2-54 through paragraph 2-119
respectively.

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2-127. AFTER STORAGE

DATA
INSPECTION TASK DESCRIPTION MECH INITIAL
REFERENCE

AFT FUSELAGE/TAILBOOM AREA

— Inspect.

1. Inspect tail rotor hub and blade assembly for damage, cracks, and
wear.

2. Inspect tail rotor elastomeric flapping bearing, crosshead seal, and

boot for evidence of deterioration.

TAIL ROTOR BLADES

— Inspect.

3. Check tail rotor blade for serviceability as follows:

a. Blade for nicks, dents, and scratches.

b. Condition of seal between mating surfaces.

c. Inspect for delamination and voids.

4. Clean tail rotor blades to maintain improved visibility.

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2-128. CONDITIONAL INSPECTIONS 2-129. AFTER HARD LANDING

Conditional inspections are non-recurring actions

following certain events that cause the helicopter to
exceed a particular limit or limits.

DATA
INSPECTION TASK DESCRIPTION MECH INITIAL
REFERENCE

NOTE
This inspection must be accomplished after a hard landing.
Refer to the BHT-206L4-MM, Chapter 5.

HARD LANDING
— Inspect.

1. If damage to fuselage structure, skid gear, or tailboom is such that a

major repair, replacement, or alignment is necessary, remove tail rotor
gearbox, hub and blade assembly, and tail rotor pitch link assemblies and
conduct a major overhaul.

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2-130. SUDDEN STOPPAGE/ACCELERATION

DATA
INSPECTION TASK DESCRIPTION MECH INITIAL
REFERENCE

SUDDEN STOPPAGE/ACCELERATION — TAIL ROTOR

Sudden stoppage/acceleration is defined as any rapid deceleration or

acceleration of the torsional drive system whether caused by seizure
within the helicopter drive system, or by contact of the tail rotor blade(s)
with the ground, water, or with foreign object of sufficient inertia to cause
rapid deceleration; or a sudden freewheeling clutch engagement,
a compressor stall causing rapid acceleration.

CAUTION

DAMAGE TO TAIL ROTOR BLADE ASSEMBLY COULD BE

P R E S E N T A LT H O U G H I T M AY N O T B E R E A D I LY
DETECTED BY STANDARD VISUAL, DIMENSIONAL, AND
MAGNETIC PARTICLE OR FLUORESCENT PENETRANT
INSPECTION METHODS.

NOTE
Components removed from helicopter for evaluation following
a sudden stoppage/acceleration shall be evaluated as an
interrelated group. Removal records accompanying each
component shall cross-reference part and serial numbers of
other drive system components removed for evaluation.

1. Remove and scrap tail rotor hub and blade assembly.

2. Overhaul the following components:

a. Tail rotor gearbox assembly.

b. Tail rotor pitch change mechanism.

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2-131. AFTER MAIN ROTOR OVERSPEED 114%

OR GREATER

DATA
INSPECTION TASK DESCRIPTION MECH INITIAL
REFERENCE

NOTE
This inspection must be accomplished after main rotor
overspeed of 114% or greater.

MAIN ROTOR OVERSPEED – 114% OR GREATER

— Inspect.

1. Tail rotor blades.

a. If one tail rotor blade of a pair has been damaged badly enough
that blade skins exhibit any delaminations or cracks or any bond plies
have separated, then both blades must be scrapped.

b. If one tail rotor blade of a pair has been damaged slightly by

denting, return both blades to a Bell Helicopter Textron authorized blade
repair facility for inspection and repair evaluation.

c. If any movement of the tip end or root end balance weights has
occurred, scrap the tail rotor blade.

d. If the tip block is cracked, scrap the tail rotor blade.

e. If tail rotor blades pass inspection requirements and no other

discrepancies exist, the blades are acceptable for continued service.

2. Tail rotor hub assemblies shall be inspected by conducting a major

overhaul.

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2-132. AFTER OVERTORQUE

DATA
INSPECTION TASK DESCRIPTION MECH INITIAL
REFERENCE

NOTE
This inspection must be accomplished after engine overtorque
of 110 to 120%.

OVERTORQUE
— Inspect for engine overtorque – 110 to 120%.

1. If engine overtorque from 110 to 120% should occur, perform the

following:

a. Pilot preflight check.

b. Conduct a visual inspection of the assemblies listed below

(installed on helicopter) for any evidence of damage, deformation,
yielding, etc.

(1) Tail rotor hub, blades, and attachments.

c. Perform the blade inspections required in step 1 same as

overspeed (114% or greater) inspection.

2. After first 25 hours following overtorque:

a. Conduct a visual inspection of the assemblies listed below

(installed on helicopter) for evidence of damage, deformation, yielding,
etc.

(1) Tail rotor hub, blades, and attachments.

Perform the blade inspections required in overspeed (114% or greater)
inspection.

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2-133. AFTER LIGHTNING STRIKE

DATA
INSPECTION TASK DESCRIPTION MECH INITIAL
REFERENCE

NOTE
This inspection must be accomplished after helicopter is
suspected of receiving a lightning strike.

LIGHTNING STRIKE
— Inspect.

1. Visually inspect all external surfaces of helicopter. Pay particular

attention to tail rotor gearbox, and tail rotor hub and blades including tail
rotor flapping bearing (elastomeric). Check TRACU control panel.
Replace defective and/or damaged parts.

2. Inspect tail rotor hub and blades. Scrap blades if indications of burns
or debonding are found. Remove tail rotor hub for overhaul. State
lightning strike as reason for removal.

3. Remove and scrap tail rotor pitch change links and crosshead
bearing. Inspect crosshead and control rod for indications of arcing.
Replace as necessary.

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2-134. COMPONENT OVERHAUL SCHEDULE SOME PARTS INSTALLED AS ORIGINAL

EQUIPMENT ON MILITARY
HELICOPTERS MAY HAVE A LOWER
The Component Overhaul Schedule (Table 2-11) AIRWORTHINESS LIFE AND/OR
provides the time interval between overhaul for each OVERHAUL SCHEDULE THAN WHEN
applicable helicopter component. USED ON A COMMERCIAL
HELICOPTER. CONSEQUENTLY, PARTS
THAT HAVE BEEN USED ON MILITARY
HELICOPTERS SHOULD NOT BE USED
WARNING
ON COMMERCIAL HELICOPTERS.

DO NOT APPLY TOLERANCES TO NOTE

PARTS WITH A LIMITED Refer to BHT-206L4-MM-1, Chapter 5 for
AIRWORTHINESS LIFE information on inspection and overhaul
(BHT-206L4-MM-1, CHAPTER 4). tolerance.

NOTE
WARNING Neither assignment of a time period for
overhaul of a component or failure to
assign a time period for overhaul of a
DO NOT EXCEED RETIREMENT LIFE component constitutes a warranty of any
FOR CRITICAL COMPONENTS. REFER kind. The only warranty applicable to
TO AIRWO RTHINESS LIMITAT IONS helicopter and any component is that
SCHEDULE ( B H T- 2 0 6 L 4 - M M - 1 , warranty included in the Purchase
CHAPTER 4). Agreement for the helicopter or component.

Table 2-11. Component Overhaul Schedule

OVERHAUL INTERVAL
PART NUMBER 1 NOMENCLATURE
HOURS

206-011-749-107 Tail Rotor Hub Assembly 2500

206-040-402-103 Tail Rotor Gearbox 6000

NOTE:

1 The overhaul interval hours for part number listed applies to all successive dash numbers for that
component, unless otherwise specified.

2-134 Rev. 2 9 JUN 2011 ECCN EAR99

BUY BELL PARTS, BUY BELL VALUE
 BHT-206-SI-2054

2-135. TAIL ROTOR HUB ASSEMBLY —

OVERHAUL INSPECTION SHEET

As necessary, operators may modify the overhaul

inspection sheet with additional information to meet
their individual needs. Contact your local airworthiness
authority for approval of any changes.

COMPONENT P/N: T.S.N.:

COMPONENT S/N: T.S.O.:

FACILITY: R.I.N.:

W.O.: DATE:

SIGNATURE:

MECH. Q.A.
LOCATION DESCRIPTION
INITIAL INITIAL

Paragraph 2-66 1. Disassemble the tail rotor hub assembly.

BHT-206L4-MM-1, 2. Discard the parts that have reached their mandatory

Chapter 4 airworthiness life limitation.

Paragraph 2-33 3. Clean the parts of the tail rotor hub assembly.

BHT-ALL-SPM, 4. Remove the paint from the painted parts.

Chapter 4

Paragraph 2-119 5. Do an inspection of the parts for wear, corrosion,

and damage.

Paragraph 2-66A 6. Do a Non Destructive Inspection (NDI).

BHT-ALL-SPM, 7. Repair the corroded or damaged parts.

Chapter 3

Table 2-12 8. Examine all the parts to make sure the tail rotor hub
assembly has the correct configuration.
BHT-ALL-SPM, 9. Apply the primer and paint to the necessary parts.
Chapter 4

Paragraph 2-67 10. Assemble the tail rotor hub assembly.

ECCN EAR99 9 JUN 2011 Rev. 2 2-135

FOR BEST VALUE, BUY GENUINE BELL PARTS
BHT-206-SI-2054

Table 2-12. Tail Rotor Hub Assembly — Configuration

TAIL ROTOR HUB ASSEMBLY

NOMENCLATURE PART NUMBER NOTES
206-011-749

-107 1 -111 -115

Yoke Assembly 406-012-102-107 2

X

Yoke Assembly 406-012-102-113 2

X X

Clamp Ring 406-012-105-101 3

X X

Clamp Ring 427-012-106-101 4

X

Weight Support 406-012-107-101 X X X

Flapping Bearing 407-312-100-101 X X X

NOTES:

1 Can be upgraded to 206-011-749-115FM with the installation of clamp ring 427-012-106-101

and sleeve 206-010-733-105. Use a vibrating stylus and change the tail rotor hub assembly dash
number as follows:
• 206-011-749-107 -115
• 206-011-749-111 -115FM

2 Refer to Table 2-13 for the yoke assembly configuration.

3 Replaced by 427-012-106-101.

4 Replaced by 406-012-105-101.

Table 2-13. Yoke Assembly — Configuration

YOKE ASSEMBLY
NOMENCLATURE PART NUMBER
406-012-102

-107 -113

Yoke 406-012-102-103 X X

Feathering Bearing 206-310-105-101 X X

Sleeve 206-010-799-103 X

Sleeve 206-010-733-105 X

2-136 Rev. 2 9 JUN 2011 ECCN EAR99

BUY BELL PARTS, BUY BELL VALUE
 BHT-206-SI-2054

2-136. WEIGHT AND BALANCE

NOTE
Weight/moments given are for kit additions.
Customer is required to determine weight
and moment for items removed and/or
re-weigh helicopter after kit installation.

LONGITUDINAL *LATERAL

HELICOPTER KIT NUMBER WEIGHT ARM MOMENT ARM MOMENT

206L4 206-704-722-101 11 281.3 +3094 -8.1 -89

(5.0) (7145) (+356.5) (-206) (-10.3)

206L4 206-704-722-111 +10.9 +280.2 +3054 -8.0 -87

(+4.9) (+7117) (+351.9) (-203) (-10.0)

206L4 206-704-722-113 +12.9 +300.0 +3870 -6.2 -80

(+5.9) (+7620) (+445.9) (-157) (-9.2)

206L4 206-704-722-117 +12.9 +300.0 +3870 -6.2 -80

(+5.9) (+7620) (+445.9) (-157) (-9.2)
*In lateral calculations, - is left, + is right.

WEIGHT pounds (kilograms)

ARM inches (millimeters)

MOMENT inch-pounds  kg × mm 
 ----------------------
100 
-

ECCN EAR99 9 JUN 2011 Rev. 2 2-137/2-138

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

CHAPTER 3 - PARTS INFORMATION AND KIT INVENTORY

TABLE OF CONTENTS

Paragraph Page
Number Title Number

3-1 Kit Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

3-2 Kit Inventory (206-704-722-101) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
3-3 Kit Inventory (206-704-722-111) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14
3-4 Kit Inventory (206-704-722-113) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25
3-5 Kit Inventory (206-704-722-117) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37

08 DEC 2004 3-1/3-2

BUY BELL PARTS - BUY BELL VALUE
 BHT-206-SI-2054

PARTS INFORMATION AND KIT INVENTORY

3-1. KIT INFORMATION

NOTE
Refer to BHT-206L-4 IPB manual. Common hardware packed with kit may
vary from that in following parts list. Some
items of this kit may be shipped
3-2. KIT INVENTORY (206-704-722-101) pre-assembled. All modifications required
for field installation of this kit will be
Part numbers in parentheses ( ) are alternate or annotated with flagnotes.
superseding part numbers.

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-101 Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-501-007-101 Modification - Directional Control System, Tail

Rotor Improvement, Consisting of:

1 206-501-007-105 Bellcrank Sub-Assembly, Consisting of:

1 206-001-820-101 Bellcrank Assembly

1 206-001-821-101 Bellcrank Assembly

1 206-301-052-103 Actuator Assembly

4 AN960JD416 Washer
(NAS1149D0463J)

1 AN960JD416L Washer
(NAS1149D0416J)

1 MS14144L4 Nut
(RME9868-4)

1 MS14145L4 Nut

48 inches MS20995C41 Lockwire (C-447)

(1219 mm) (AS100029)

2 MS24665-155 Cotter Pin

1 NAS6604D13 Bolt

1 NAS6604D20 Bolt

1 NAS6604H12 Bolt

2 120-032-16-8 Shim

1 206-001-097-101 Tube Assembly

1 206-001-822-101 Idler Assembly

1 206-001-823-101 Link Assembly

08 DEC 2004 3-3

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-101 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-501-007-101 (Cont) Modification - Directional Control System, Tail

Rotor Improvement, Consisting of:

1 206-001-824-101 Bellcrank Assembly

1 206-001-825-101 Support Assembly

6 AN960JD10L Washer
(NAS1149D0332J)

13 AN960JD416 Washer
(NAS1149D0463J)

1 AN960JD416L Washer
(NAS1149D0416J)

2 AN960JD516 Washer
(NAS1149D0563J)

2 AN960JD616L Washer
(NAS1149D0616J)

5 MS14144L4 Nut
(RME9868-4)

1 MS14144L5 Nut
(RME9868-5)

1 MS14144L6 Nut
(RME9868-6)

10 ft (3 m) MS20995C32 Lockwire (C-405)

(AS100028)

5 MS21042L3 Nut

7 MS24665-155 Cotter Pin

1 MS24665-302 Cotter Pin

1 MS27039-1-12 Screw

1 NAS6603-5 Bolt

1 NAS6604D12 Bolt

1 NAS6604D15 Bolt

1 NAS6604D21 Bolt

1 NAS6604D23 Bolt

1 NAS6604D24 Bolt

2 NAS6604H4 Bolt

3-4 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-101 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-501-007-101 (Cont) Modification - Directional Control System, Tail

Rotor Improvement, Consisting of:

1 NAS6605D13 Bolt

1 NAS6606D38 Bolt

3 100-048-6-7 Pin

4 120-032-16-8 Shim

1 120-032-16-10 Shim

1 140-002-2 Washer

1 oz. (28 g) 299-947-100, Type II, CL 2 Adhesive (C-317)

1 206-510-003-103 Modification - Tail Rotor, Consisting of:

1 206-011-726-005 Bushing

2 206-011-741-101 Lever Assembly

1 1 206-011-749-105 Hub and Blade Assembly, Consisting of:

1 206-011-749-107 Hub Assembly

4 206-011-750-103 Support

REF 206-210-100-101 T/R Bal Set

(T101280-111)

REF 206-210-100-103 T/R Bal Adapter

8 212-010-710-109 Weight

16 212-010-710-111 Weight

2 400-016-100-109 Blade Assembly

(400-016-100-113)

2 406-012-108-101 Pitch Horn Assembly

20 AN960-416 Washer
(NAS1149F0463P)

8 AN960-616 Washer
(NAS1149F0663P)

8 AN960-616L Washer
(NAS1149F0632P)

6 AN970-4 Washer

12 AN970-6 Washer

08 DEC 2004 3-5

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-101 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-510-003-103 (Cont) Modification - Tail Rotor, Consisting of:

1 1 206-011-749-105 (Cont) Hub and Blade Assembly, Consisting of:

4 MS14144L4 Nut
(RME9868-4)

4 MS14144L6 Nut
(RME9868-6)

2 MS21042L4 Nut

4 MS21042L5 Nut

4 MS24665-132 Cotter Pin

4 MS24665-283 Cotter Pin

(MS24665-285)

2 NAS6204-1 Bolt

4 NAS6204-29D Bolt

2 NAS6204-3 Bolt

2 NAS6204-5 Bolt

2 NAS6204-7 Bolt

2 NAS6204-9 Bolt

4 NAS6605-15 Bolt

4 NAS6605-16 Bolt

4 NAS6605-17 Bolt

2 NAS6606D30 Bolt

2 NAS6606D31 Bolt

2 NAS6606D32 Bolt

2 NAS6606D34 Bolt

4 NAS6606D36 Bolt

2 NAS6606D37 Bolt

4 NAS6606D38 Bolt

2 NAS6606D39 Bolt

8 140-007-25-22C4 Washer

3-6 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-101 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-510-003-103 (Cont) Modification - Tail Rotor, Consisting of:

1 206-011-751-101 Rod Assembly

1 406-012-104-103 Plate

1 406-012-110-101 Spacer

1 406-012-113-101 Nut

1 406-012-118-101 Tube Assembly

1 406-012-127-101 Idler Assembly

1 406-312-102-101 Seal, Sliding

2 406-312-103-101 Pitch Link

1 406-312-106-101 Boot, Tail Rotor

1 407-012-105-101 Crosshead

1 407-012-106-101 Support

4 AN3H7A Bolt

4 AN960-10L Washer
(NAS1149F0332P)

14 AN960-416 Washer
(NAS1149F0463P)

2 AN960-416L Washer
(NAS1149F0432P)

1 AN960-616L Washer
(NAS1149F0632P)

1 AN960-816 Washer
(NAS1149F0863P)

2 AN960PD416 Washer
(NAS1149D0463J)

6 MS14144L4 Nut
(RME9868-4)

1 MS14145L6 Nut

1 MS14145L8 Nut

10 ft (3 m) MS20995C32 Lockwire (C-405)

(AS100028)

3 MS21042L4 Nut

08 DEC 2004 3-7

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-101 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-510-003-103 (Cont) Modification - Tail Rotor, Consisting of:

6 MS24665-155 Cotter Pin

1 MS24665-289 Cotter Pin

1 MS24665-306 Pin

3 NAS1197-416 Washer

2 NAS577-4A Nut
(NAS577B4A)

2 NAS578-4B Retainer

2 NAS6604D14 Bolt

1 NAS6604D15 Bolt

1 NAS6604D21 Bolt

1 NAS6604D31 Bolt

1 NAS6604D32 Bolt

2 NAS6604H22 Bolt

2 NAS6604H3 Bolt

1 2-38N141-7 Seal O-ring

(AS3209-038)

6 oz. (170 g) MIL-C-16173, Grade 2 Corrosion Preventive Compound (C-104)

6 oz. (170 g) MIL-C-16173, Grade 1 Corrosion Preventive Compound (C-101)

8 oz. (227 g) MIL-G-81322 Grease (C-001)

6 oz. (170 g) MIL-S-8802 Adhesive (C-308)

1 206-530-123-103 Modification - Fuselage Assembly, Consisting of:

1 206-023-133-101 Doubler Assembly

1 206-230-100-101 Work Aid

1 206-530-123-107 Support Assembly

1 206-530-123-121 Doubler

2 206-530-123-123 Splice Angle

1 206-530-123-125 Bracket

2 MS20426AD3-4 Rivet

4 MS20470AD4-4 Rivet

3-8 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-101 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-530-123-103 (Cont) Modification - Fuselage Assembly, Consisting of:

8 MS20470AD4-5 Rivet

1 MS21059L3 Nutplate

17 M7885/2-4-02 Rivet
(NAS9301B-4-02)

4 M7885/2-4-03 Rivet
(NAS9301B-4-03)

1 M7885/3-4-02 Rivet
(NAS9302B-4-02)

13 M7885/6-4-02 Rivet
(NAS9304B-4-02)

38 M7885/6-4-03 Rivet
(NAS9304B-4-03)

2 M7885/6-4-04 Rivet
(NAS9304B-4-04)

5 NAS1097AD4-4 Rivet

2 100-050B250 Plug Button

1 100-088-1 Identification Plate

(100-088-2)

3.5 oz. 299-947-100, Type II, CL 2 Adhesive (C-317)

(100 g)

36 inches 299-947-110, Type II Tape, 1 inch (25.4 mm) width (C-454)

(915 mm)

4 oz. (113 g) MIL-PRF-81733 Sealant (C-392)

1 206-540-004-101 Modification - Drive System Installation, Consisting

of:

1 206-540-005-101 Modification - Gearbox Assembly, Tail Rotor,

Consisting of:

1 206-040-949-101 Shaft

1 MS24665-227 Cotter Pin

1 M83248/1-244 Packing
(AS3209-244)

1 29800-8054 Wear Sleeve

(536827)
(206-340-401-101)

08 DEC 2004 3-9

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-101 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-540-004-101 (Cont) Modification - Drive System Installation, Consisting

of:

1 206-540-005-101 (Cont) Modification - Gearbox Assembly, Tail Rotor,

Consisting of:

1 100-024-1 Identification Plate

(100-140-2)

2 oz. 299-947-100, Type II, CL 2 Adhesive (C-317)

(57 g)

8 oz. MIL-G-81322 Grease (C-001)

(227 g)

8 oz. MIL-S-8784 Sealing Compound (C-328)

(227 g)

1 206-575-200-101 Modification - Tail Rotor Authority, Consisting of:

1 206-075-798-101 Decal

1 206-075-799-101 Plate

1 206-575-200-103 Modification - Panel Assembly, Consisting of:

1 25-0195-3269 Filter

1 206-575-200-105 Modification - Shell Assembly, Consisting of:

1 206-575-200-115 Doubler

1 AN960JD716L Washer
(NAS1149D0716J)

1 MS28034-3 Temperature Bulb

1 MS35333-121 Lock Washer

1 MS35691-29 Nut

1 31-065-9E1 Decal

8 oz. MIL-PRF-81733 Sealant (C-392)

(227 g)

8 oz. 299-947-100, Type II, CL 2 Adhesive (C-317)

(227 g)

1 206-575-200-107 Modification - Overhead Panel, Consisting of:

1 MS26574-1-1/2 Circuit Breaker

1 31-026-1353H12 Decal

1 31-026-527H12 Decal

3-10 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-101 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-575-200-109 Modification - Console, Consisting of:

1 206-074-124-111 Control Panel Assembly

(206-074-124-113)

4 MS35215-56 Screw

1 206-575-200-111 Modification - Electrical Installation, Consisting of:

3 AN960JD10L Washer
(NAS1149D0332J)

4 AN960JD4L Washer
(NAS1149DN416J)

3 MS21042L3 Nut

2 MS21919WDG4 Clamp

6 MS25281-R9 Clamp

2 MS27039-1-06 Screw

1 MS27039-1-07 Screw

50 MS3367-1-9 Strap, Tie

4 MS35206-215 Screw

2 MS35489-12 Grommet

1 MS9592-012 Bracket

2 M81714/60-22-05 Terminal Module

1 M85528/2-12A01 Mounting Flange

(M85049/95-12A-A)

1 CTJ-3A-02 Rail Assembly

1 120-150-11 Solder, Sleeve

(120-150-14)

1 160-032-04C Electrical Installation, Consisting of:

1 A10099 Band, EMI

(20-108-1)

1 20-036-24-20N Braid

1 130-045-30R-4-0-4 Sleeving

1 130-053-1-0-20 Sleeving

1 202D121-4/86 Shrink Boot

2 XTPA-080 Meltable Tape

08 DEC 2004 3-11

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-101 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-575-200-101 (Cont) Modification - Tail Rotor Authority, Consisting of:

1 206-575-200-111 (Cont) Modification - Electrical Installation, Consisting of:

1 31-065-9B1J1 Decal

1 31-065-9TB1 Decal

1 33-001-002-1-08 Support Installation

1 33-001-107C Support Installation

8 oz. 299-947-100, Type II, CL 4 Adhesive (C-311)

(227 g)

1 206-575-200-113 Cable Assembly, Consisting of:

1 D38999/20WB35SN Connector

1 ETC-A1A1204X Backshell
(ETC-A1A1204H)

1 MS25036-103 Terminal

1 MS25036-149 Terminal

2 MS25036-156 Terminal Lug

1 MS3459W12S-3S Connector

AR M22759/41-12-9 Wire
(140-039-12)

AR M22759/41-22-9 Wire
(140-039-22)

1 M24308/2-4 Connector
(M24308/2-4F)

2 M24308/25-9F Screw Assembly

4 M39029/1-101 Contact

29 M39029/22-191 Contact

2 M39029/30-217 Contact

13 M39029/56-348 Contact

37 M39029/63-368 Contact

8 M83519/2-7 Shield Term

5 M83519/2-8 Shield Term

1 M85049/38-11W Strain Relief

3-12 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-101 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-575-200-101 (Cont) Modification - Tail Rotor Authority, Consisting of:

1 206-575-200-113 (Cont) Cable Assembly, Consisting of:

1 M85049/48-2-4F Backshell

AR M85485/12-22T2A Cable
(30-279-22-2)

10 030-01107-0000 Terminal

1 100-2020S Contact
(M39029/35-274)

1 130-053-4-0-48 Sleeving

AR 30-231-22D1 Cable
(30-286-22-1)

AR 30-231-22D2 Wire
(30-284-22-2)

4 MS35214-28 Screw

1 BHT-206L4-FMS-19 Flight Manual Supplement

1
BHT-206-SI-2054 Service Instruction

NOTE:

1 The hub and blade assembly supplied in kit will be assembled and balanced. Parts within the hub and blade
assembly are for field reference only.

08 DEC 2004 3-13

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

3-3. KIT INVENTORY (206-704-722-111) Some items of this kit may be shipped
pre-assembled. All modifications required
Part numbers in parentheses ( ) are alternate or for field installation of this kit will be
superseding part numbers. annotated with flagnotes.

NOTE
Common hardware packed with kit may
vary from that in following parts list.

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-111 Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-501-007-101 Modification - Directional Control System, Tail

Rotor Improvement, Consisting of:

1 206-501-007-105 Bellcrank Sub-Assembly, Consisting of:

1 206-001-820-101 Bellcrank Assembly

1 206-001-821-101 Bellcrank Assembly

1 206-301-052-103 Actuator Assembly

4 AN960JD416 Washer
(NAS1149D0463J)

1 AN960JD416L Washer
(NAS1149D0416J)

1 MS14144L4 Nut
(RME9868-4)

1 MS14145L4 Nut

48 inches MS20995C41 Lockwire (C-447)

(1219 mm) (AS100029)

2 MS24665-155 Cotter Pin

1 NAS6604D13 Bolt

1 NAS6604D20 Bolt

1 NAS6604H12 Bolt

2 120-032-16-8 Shim

1 206-001-097-101 Tube Assembly

1 206-001-822-101 Idler Assembly

1 206-001-823-101 Link Assembly

1 206-001-824-101 Bellcrank Assembly

1 206-001-825-101 Support Assembly

3-14 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-111 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-501-007-101 (Cont) Modification - Directional Control System, Tail

Rotor Improvement, Consisting of:

6 AN960JD10L Washer
(NAS1149D0332J)

13 AN960JD416 Washer
(NAS1149D0463J)

1 AN960JD416L Washer
(NAS1149D0416J)

2 AN960JD516 Washer
(NAS1149D0563J)

2 AN960JD616L Washer
(NAS1149D0616J)

5 MS14144L4 Nut
(RME9868-4)

1 MS14144L5 Nut
(RME9868-5)

1 MS14144L6 Nut
(RME9868-6)

10 ft (3 m) MS20995C32 Lockwire (C-405)

(AS100028)

5 MS21042L3 Nut

7 MS24665-155 Cotter Pin

1 MS24665-302 Cotter Pin

1 MS27039-1-12 Screw

1 NAS6603-5 Bolt

1 NAS6604D12 Bolt

1 NAS6604D15 Bolt

1 NAS6604D21 Bolt

1 NAS6604D23 Bolt

1 NAS6604D24 Bolt

2 NAS6604H4 Bolt

1 NAS6605D13 Bolt

1 NAS6606D38 Bolt

08 DEC 2004 3-15

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-111 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-501-007-101 (Cont) Modification - Directional Control System, Tail

Rotor Improvement, Consisting of:

3 100-048-6-7 Pin

4 120-032-16-8 Shim

1 120-032-16-10 Shim

1 140-002-2 Washer

1 oz. (28 g) 299-947-100, Type II, CL 2 Adhesive (C-317)

1 1 206-510-003-107 Modification - Tail Rotor, Consisting of:

1 206-011-726-005 Bushing

2 206-011-741-101 Lever Assembly

1 206-011-749-109 Hub and Blade Assembly, Consisting of:

1 206-011-749-111 Hub Assembly

4 206-011-750-103 Support

REF 206-210-100-101 T/R Bal Set

(T101280-111)

REF 206-210-100-103 T/R Bal Adapter

8 212-010-710-109 Weight

16 212-010-710-111 Weight

2 400-016-100-109 Blade Assembly

(400-016-100-113)

2 406-012-108-101 Pitch Horn Assembly

20 AN960-416 Washer
(NAS1149F0463P)

8 AN960-616 Washer
(NAS1149F0663P)

8 AN960-616L Washer
(NAS1149F0632P)

6 AN970-4 Washer

12 AN970-6 Washer

4 MS14144L4 Nut
(RME9868-4)

3-16 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-111 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 1 206-510-003-107 (Cont) Modification - Tail Rotor, Consisting of:

1 206-011-749-109 (Cont) Hub and Blade Assembly, Consisting of:

4 MS14144L6 Nut
(RME9868-6)

2 MS21042L4 Nut

4 MS21042L5 Nut

4 MS24665-132 Cotter Pin

4 MS24665-283 Cotter Pin

(MS24665-285)

2 NAS6204-1 Bolt

4 NAS6204-29D Bolt

2 NAS6204-3 Bolt

2 NAS6204-5 Bolt

2 NAS6204-7 Bolt

2 NAS6204-9 Bolt

4 NAS6605-15 Bolt

4 NAS6605-16 Bolt

4 NAS6605-17 Bolt

2 NAS6606D30 Bolt

2 NAS6606D31 Bolt

2 NAS6606D32 Bolt

2 NAS6606D34 Bolt

4 NAS6606D36 Bolt

2 NAS6606D37 Bolt

4 NAS6606D38 Bolt

2 NAS6606D39 Bolt

8 140-007-25-22C4 Washer

1 206-011-751-101 Rod Assembly

1 206-011-752-101 Support

1 406-012-104-103 Plate

08 DEC 2004 3-17

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-111 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 1 206-510-003-107 (Cont) Modification - Tail Rotor, Consisting of:

1 406-012-110-101 Spacer

1 406-012-113-101 Nut

1 406-012-118-101 Tube Assembly

1 406-012-127-101 Idler Assembly

1 406-312-102-101 Seal, Sliding

2 406-312-103-101 Pitch Link

1 406-312-106-101 Boot, Tail Rotor

1 407-012-105-101 Crosshead

4 AN3H7A Bolt

4 AN960-10L Washer
(NAS1149F0332P)

14 AN960-416 Washer
(NAS1149F0463P)

2 AN960-416L Washer
(NAS1149F0432P)

1 AN960-616L Washer
(NAS1149F0632P)

1 AN960-816 Washer
(NAS1149F0863P)

2 AN960PD416 Washer
(NAS1149D0463J)

6 MS14144L4 Nut
(RME9868-4)

1 MS14145L6 Nut

1 MS14145L8 Nut

10 ft (3 m) MS20995C32 Lockwire (C-405)

(AS100028)

3 MS21042L4 Nut

6 MS24665-155 Cotter Pin

1 MS24665-289 Cotter Pin

1 MS24665-306 Pin

3-18 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-111 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 1 206-510-003-107 (Cont) Modification - Tail Rotor, Consisting of:

3 NAS1197-416 Washer

2 NAS577-4A Nut
(NAS577B4A)

2 NAS578-4B Retainer

2 NAS6604D14 Bolt

1 NAS6604D15 Bolt

1 NAS6604D21 Bolt

1 NAS6604D31 Bolt

1 NAS6604D32 Bolt

2 NAS6604H22 Bolt

2 NAS6604H3 Bolt

1 2-38N141-7 Seal O-ring

(AS3209-038)

6 oz. (170 g) MIL-C-16173, Grade 2 Corrosion Preventive Compound (C-104)

6 oz. (170 g) MIL-C-16173, Grade 1 Corrosion Preventive Compound (C-101)

8 oz. (227 g) MIL-G-81322 Grease (C-001)

6 oz. (170 g) MIL-S-8802 Adhesive (C-308)

1 206-530-123-103 Modification - Fuselage Assembly, Consisting of:

1 206-023-133-101 Doubler Assembly

1 206-230-100-101 Work Aid

1 206-530-123-107 Support Assembly

1 206-530-123-121 Doubler

2 206-530-123-123 Splice Angle

1 206-530-123-125 Bracket

2 MS20426AD3-4 Rivet

4 MS20470AD4-4 Rivet

8 MS20470AD4-5 Rivet

1 MS21059L3 Nutplate

08 DEC 2004 3-19

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-111 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-530-123-103 (Cont) Modification - Fuselage Assembly, Consisting of:

17 M7885/2-4-02 Rivet
(NAS9301B-4-02)

4 M7885/2-4-03 Rivet
(NAS9301B-4-03)

1 M7885/3-4-02 Rivet
(NAS9302B-4-02)

13 M7885/6-4-02 Rivet
(NAS9304B-4-02)

38 M7885/6-4-03 Rivet
(NAS9304B-4-03)

2 M7885/6-4-04 Rivet
(NAS9304B-4-04)

5 NAS1097AD4-4 Rivet

2 100-050B250 Plug Button

1 100-088-1 Identification Plate

(100-088-2)

3.5 oz. 299-947-100, Type II, CL 2 Adhesive (C-317)

(100 g)

36 inches 299-947-110, Type II Tape, 1 inch (25.4 mm) width (C-454)

(915 mm)

4 oz. (113 g) MIL-PRF-81733 Sealant (C-392)

1 206-540-004-101 Modification - Drive System Installation, Consisting

of:

1 206-540-005-101 Modification - Gearbox Assembly, Tail Rotor,

Consisting of:

1 206-040-949-101 Shaft

1 MS24665-227 Cotter Pin

1 M83248/1-244 Packing
(AS3209-244)

1 29800-8054 Wear Sleeve

(536827)
(206-340-401-101)

1 100-024-1 Identification Plate

(100-140-2)

3-20 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-111 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-540-004-101 (Cont) Modification - Drive System Installation, Consisting

of:

1 206-540-005-101 (Cont) Modification - Gearbox Assembly, Tail Rotor,

Consisting of:

2 oz. 299-947-100, Type II, CL 2 Adhesive (C-317)

(57 g)

8 oz. MIL-G-81322 Grease (C-001)

(227 g)

8 oz. MIL-S-8784 Sealing Compound (C-328)

(227 g)

1 206-575-200-101 Modification - Tail Rotor Authority, Consisting of:

1 206-075-798-101 Decal

1 206-075-799-101 Plate

1 206-575-200-103 Modification - Panel Assembly, Consisting of:

1 25-0195-3269 Filter

1 206-575-200-105 Modification - Shell Assembly, Consisting of:

1 206-575-200-115 Doubler

1 AN960JD716L Washer
(NAS1149D0716J)

1 MS28034-3 Temperature Bulb

1 MS35333-121 Lock Washer

1 MS35691-29 Nut

1 31-065-9E1 Decal

8 oz. MIL-PRF-81733 Sealing Compound (C-392)

(227 g)

8 oz. 299-947-100, Type II, CL 2 Adhesive (C-317)

(227 g)

1 206-575-200-107 Modification - Overhead Panel, Consisting of:

1 MS26574-1-1/2 Circuit Breaker

1 31-026-1353H12 Decal

1 31-026-527H12 Decal

08 DEC 2004 3-21

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-111 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-575-200-101 (Cont) Modification - Tail Rotor Authority, Consisting of:

1 206-575-200-109 Modification - Console, Consisting of:

1 206-074-124-111 Control Panel Assembly

(206-074-124-113)

4 MS35215-56 Screw

1 206-575-200-111 Modification - Electrical Installation, Consisting of:

3 AN960JD10L Washer
(NAS1149D0332J)

4 AN960JD4L Washer
(NAS1149DN416J)

3 MS21042L3 Nut

2 MS21919WDG4 Clamp

6 MS25281-R9 Clamp

2 MS27039-1-06 Screw

1 MS27039-1-07 Screw

50 MS3367-1-9 Strap, Tie

4 MS35206-215 Screw

2 MS35489-12 Grommet

1 MS9592-012 Bracket

2 M81714/60-22-05 Terminal Module

1 M85528/2-12A01 Mounting Flange

(M85049/95-12A-A)

1 CTJ-3A-02 Rail Assembly

1 120-150-11 Solder, Sleeve

(120-150-14)

1 160-032-04C Electrical Installation, Consisting of:

1 A10099 Band, EMI

(20-108-1)

1 20-036-24-20N Braid

1 130-045-30R-4-0-4 Sleeving

1 130-053-1-0-20 Sleeving

1 202D121-4/86 Shrink Boot

3-22 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-111 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-575-200-101 (Cont) Modification - Tail Rotor Authority, Consisting of:

1 206-575-200-111 (Cont) Modification - Electrical Installation, Consisting of:

1 160-032-04C (Cont) Electrical Installation, Consisting of:

2 XTPA-080 Meltable Tape

1 31-065-9B1J1 Decal

1 31-065-9TB1 Decal

1 33-001-002-1-08 Support Installation

1 33-001-107C Support Installation

8 oz. 299-947-100, Type II, CL 4 Adhesive (C-311)

(227 g)

1 206-575-200-113 Cable Assembly, Consisting of:

1 D38999/20WB35SN Connector

1 ETC-A1A1204X Backshell
(ETC-A1A1204H)

1 MS25036-103 Terminal

1 MS25036-149 Terminal

2 MS25036-156 Terminal Lug

1 MS3459W12S-3S Connector

AR M22759/41-12-9 Wire
(140-039-12)

AR M22759/41-22-9 Wire
(140-039-22)

1 M24308/2-4 Connector
(M24308/2-4F)

2 M24308/25-9F Screw Assembly

4 M39029/1-101 Contact

29 M39029/22-191 Contact

2 M39029/30-217 Contact

13 M39029/56-348 Contact

37 M39029/63-368 Contact

8 M83519/2-7 Shield Term

08 DEC 2004 3-23

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-111 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-575-200-101 (Cont) Modification - Tail Rotor Authority, Consisting of:

1 206-575-200-113 (Cont) Cable Assembly, Consisting of:

5 M83519/2-8 Shield Term

1 M85049/38-11W Strain Relief

1 M85049/48-2-4F Backshell

AR M85485/12-22T2A Cable
(30-279-22-2)

10 030-01107-0000 Terminal

1 100-2020S Contact
(M39029/35-274)

1 130-053-4-0-48 Sleeving

AR 30-231-22D1 Cable
(30-286-22-1)

AR 30-231-22D2 Wire
(30-284-22-2)

4 MS35214-28 Screw

1 BHT-206L4-FMS-19 Flight Manual Supplement

1 BHT-206-SI-2054 Service Instruction

NOTE:

1 The hub and blade assembly supplied in kit will be assembled and balanced. Parts within the hub and blade
assembly are for field reference only.

3-24 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

3-4. KIT INVENTORY (206-704-722-113) Some items of this kit may be shipped
pre-assembled. All modifications required
Part numbers in parentheses ( ) are alternate or for field installation of this kit will be
superseding part numbers. annotated with flagnotes.

NOTE
Common hardware packed with kit may
vary from that in following parts list.

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-113 Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-020-110-103 Tail Skid Assembly, Consisting of:

1 206-020-110-117 Skid

AR TUBEBORIUM Tube

1 206-501-007-101 Modification - Directional Control System, Tail

Rotor Improvement, Consisting of:

1 206-501-007-105 Bellcrank Sub-Assembly, Consisting of:

1 206-001-820-101 Bellcrank Assembly

1 206-001-821-101 Bellcrank Assembly

1 206-301-052-103 Actuator Assembly

4 AN960JD416 Washer
(NAS1149D0463J)

1 AN960JD416L Washer
(NAS1149D0416J)

1 MS14144L4 Nut
(RME9868-4)

1 MS14145L4 Nut

48 inches MS20995C41 Lockwire (C-447)

(1219 mm) (AS100029)

2 MS24665-155 Cotter Pin

1 NAS6604D13 Bolt

1 NAS6604D20 Bolt

1 NAS6604H12 Bolt

2 120-032-16-8 Shim

1 206-001-097-101 Tube Assembly

1 206-001-822-101 Idler Assembly

08 DEC 2004 3-25

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-113 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-501-007-101 (Cont) Modification - Directional Control System, Tail

Rotor Improvement, Consisting of:

1 206-001-823-101 Link Assembly

1 206-001-824-101 Bellcrank Assembly

1 206-001-825-101 Support Assembly

6 AN960JD10L Washer
(NAS1149D0332J)

13 AN960JD416 Washer
(NAS1149D0463J)

1 AN960JD416L Washer
(NAS1149D0416J)

2 AN960JD516 Washer
(NAS1149D0563J)

2 AN960JD616L Washer
(NAS1149D0616J)

5 MS14144L4 Nut
(RME9868-4)

1 MS14144L5 Nut
(RME9868-5)

1 MS14144L6 Nut
(RME9868-6)

10 ft (3 m) MS20995C32 Lockwire (C-405)

(AS100028)

5 MS21042L3 Nut

7 MS24665-155 Cotter Pin

1 MS24665-302 Cotter Pin

1 MS27039-1-12 Screw

1 NAS6603-5 Bolt

1 NAS6604D12 Bolt

1 NAS6604D15 Bolt

1 NAS6604D21 Bolt

1 NAS6604D23 Bolt

1 NAS6604D24 Bolt

3-26 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-113 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-501-007-101 (Cont) Modification - Directional Control System, Tail

Rotor Improvement, Consisting of:

2 NAS6604H4 Bolt

1 NAS6605D13 Bolt

1 NAS6606D38 Bolt

3 100-048-6-7 Pin

4 120-032-16-8 Shim

1 120-032-16-10 Shim

1 140-002-2 Washer

1 oz. (28 g) 299-947-100, Type II, CL 2 Adhesive (C-317)

1 1 206-510-003-107 Modification - Tail Rotor, Consisting of:

1 206-011-726-005 Bushing

2 206-011-741-101 Lever Assembly

1 206-011-749-109 Hub and Blade Assembly, Consisting of:

1 206-011-749-111 Hub Assembly

4 206-011-750-103 Support

REF 206-210-100-101 T/R Bal Set

(T101280-111)

REF 206-210-100-103 T/R Bal Adapter

8 212-010-710-109 Weight

16 212-010-710-111 Weight

2 400-016-100-109 Blade Assembly

(400-016-100-113)

2 406-012-108-101 Pitch Horn Assembly

20 AN960-416 Washer
(NAS1149F0463P)

8 AN960-616 Washer
(NAS1149F0663P)

8 AN960-616L Washer
(NAS1149F0632P)

6 AN970-4 Washer

08 DEC 2004 3-27

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-113 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 1 206-510-003-107 (Cont) Modification - Tail Rotor, Consisting of:

1 206-011-749-109 (Cont) Hub and Blade Assembly, Consisting of:

12 AN970-6 Washer

4 MS14144L4 Nut
(RME9868-4)

4 MS14144L6 Nut
(RME9868-6)

2 MS21042L4 Nut

4 MS21042L5 Nut

4 MS24665-132 Cotter Pin

4 MS24665-283 Cotter Pin

(MS24665-285)

2 NAS6204-1 Bolt

4 NAS6204-29D Bolt

2 NAS6204-3 Bolt

2 NAS6204-5 Bolt

2 NAS6204-7 Bolt

2 NAS6204-9 Bolt

4 NAS6605-15 Bolt

4 NAS6605-16 Bolt

4 NAS6605-17 Bolt

2 NAS6606D30 Bolt

2 NAS6606D31 Bolt

2 NAS6606D32 Bolt

2 NAS6606D34 Bolt

4 NAS6606D36 Bolt

2 NAS6606D37 Bolt

4 NAS6606D38 Bolt

2 NAS6606D39 Bolt

8 140-007-25-22C4 Washer

3-28 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-113 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 1 206-510-003-107 (Cont) Modification - Tail Rotor, Consisting of:

1 206-011-751-101 Rod Assembly

1 206-011-752-101 Support

1 406-012-104-103 Plate

1 406-012-110-101 Spacer

1 406-012-113-101 Nut

1 406-012-118-101 Tube Assembly

1 406-012-127-101 Idler Assembly

1 406-312-102-101 Seal, Sliding

2 406-312-103-101 Pitch Link

1 406-312-106-101 Boot, Tail Rotor

1 407-012-105-101 Crosshead

4 AN3H7A Bolt

4 AN960-10L Washer
(NAS1149F0332P)

14 AN960-416 Washer
(NAS1149F0463P)

2 AN960-416L Washer
(NAS1149F0432P)

1 AN960-616L Washer
(NAS1149F0632P)

1 AN960-816 Washer
(NAS1149F0863P)

2 AN960PD416 Washer
(NAS1149D0463J)

6 MS14144L4 Nut
(RME9868-4)

1 MS14145L6 Nut

1 MS14145L8 Nut

10 ft (3 m) MS20995C32 Lockwire (C-405)

(AS100028)

3 MS21042L4 Nut

08 DEC 2004 3-29

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-113 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 1 206-510-003-107 (Cont) Modification - Tail Rotor, Consisting of:

6 MS24665-155 Cotter Pin

1 MS24665-289 Cotter Pin

1 MS24665-306 Pin

3 NAS1197-416 Washer

2 NAS577-4A Nut
(NAS577B4A)

2 NAS578-4B Retainer

2 NAS6604D14 Bolt

1 NAS6604D15 Bolt

1 NAS6604D21 Bolt

1 NAS6604D31 Bolt

1 NAS6604D32 Bolt

2 NAS6604H22 Bolt

2 NAS6604H3 Bolt

1 2-38N141-7 Seal O-ring

(AS3209-038)

6 oz. (170 g) MIL-C-16173, Grade 2 Corrosion Preventive Compound (C-104)

6 oz. (170 g) MIL-C-16173, Grade 1 Corrosion Preventive Compound (C-101)

8 oz. (227 g) MIL-G-81322 Grease (C-001)

6 oz. (170 g) MIL-S-8802 Adhesive (C-308)

1 206-530-123-103 Modification - Fuselage Assembly, Consisting of:

1 206-023-133-101 Doubler Assembly

1 206-230-100-101 Work Aid

1 206-530-123-107 Support Assembly

1 206-530-123-121 Doubler

2 206-530-123-123 Splice Angle

1 206-530-123-125 Bracket

2 MS20426AD3-4 Rivet

4 MS20470AD4-4 Rivet

3-30 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-113 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-530-123-103 (Cont) Modification - Fuselage Assembly, Consisting of:

8 MS20470AD4-5 Rivet

1 MS21059L3 Nutplate

17 M7885/2-4-02 Rivet
(NAS9301B-4-02)

4 M7885/2-4-03 Rivet
(NAS9301B-4-03)

1 M7885/3-4-02 Rivet
(NAS9302B-4-02)

13 M7885/6-4-02 Rivet
(NAS9304B-4-02)

38 M7885/6-4-03 Rivet
(NAS9304B-4-03)

2 M7885/6-4-04 Rivet
(NAS9304B-4-04)

5 NAS1097AD4-4 Rivet

2 100-050B250 Plug Button

1 100-088-1 Identification Plate

(100-088-2)

3.5 oz. 299-947-100, Type II, CL 2 Adhesive (C-317)

(100 g)

36 inches 299-947-110, Type II Tape, 1 inch (25.4 mm) width (C-454)

(915 mm)

4 oz. (113 g) MIL-PRF-81733 Sealant (C-392)

1 206-540-004-101 Modification - Drive System Installation, Consisting

of:

1 206-540-005-101 Modification - Gearbox Assembly, Tail Rotor,

Consisting of:

1 206-040-949-101 Shaft

1 MS24665-227 Cotter Pin

1 M83248/1-244 Packing
(AS3209-244)

1 29800-8054 Wear Sleeve

(536827)
(206-340-401-101)

08 DEC 2004 3-31

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-113 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-540-004-101 (Cont) Modification - Drive System Installation, Consisting

of:

1 206-540-005-101 (Cont) Modification - Gearbox Assembly, Tail Rotor,

Consisting of:

1 100-024-1 Identification Plate

(100-140-2)

2 oz. 299-947-100, Type II, CL 2 Adhesive (C-317)

(57 g)

8 oz. MIL-G-81322 Grease (C-001)

(227 g)

8 oz. MIL-S-8784 Sealing Compound (C-328)

(227 g)

1 206-575-200-101 Modification - Tail Rotor Authority, Consisting of:

1 206-075-798-101 Decal

1 206-075-799-101 Plate

1 206-575-200-103 Modification - Panel Assembly, Consisting of:

1 25-0195-3269 Filter

1 206-575-200-105 Modification - Shell Assembly, Consisting of:

1 206-575-200-115 Doubler

1 AN960JD716L Washer
(NAS1149D0716J)

1 MS28034-3 Temperature Bulb

1 MS35333-121 Lock Washer

1 MS35691-29 Nut

1 31-065-9E1 Decal

8 oz. MIL-PRF-81733 Sealant (C-392)

(227 g)

8 oz. 299-947-100, Type II, CL 2 Adhesive (C-317)

(227 g)

1 206-575-200-107 Modification - Overhead Panel, Consisting of:

1 MS26574-1-1/2 Circuit breaker

1 31-026-1353H12 Decal

3-32 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-113 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-575-200-101 (Cont) Modification - Tail Rotor Authority, Consisting of:

1 206-575-200-107 (Cont) Modification - Overhead Panel, Consisting of:

1 31-026-527H12 Decal

1 206-575-200-109 Modification - Console, Consisting of:

1 206-074-124-111 Control Panel Assembly

(206-074-124-113)

4 MS35215-56 Screw

1 206-575-200-111 Modification - Electrical Installation, Consisting of:

3 AN960JD10L Washer
(NAS1149D0332J)

4 AN960JD4L Washer
(NAS1149DN416J)

3 MS21042L3 Nut

2 MS21919WDG4 Clamp

6 MS25281-R9 Clamp

2 MS27039-1-06 Screw

1 MS27039-1-07 Screw

50 MS3367-1-9 Strap, Tie

4 MS35206-215 Screw

2 MS35489-12 Grommet

1 MS9592-012 Bracket

2 M81714/60-22-05 Terminal Module

1 M85528/2-12A01 Mounting Flange

(M85049/95-12A-A)

1 CTJ-3A-02 Rail Assembly

1 120-150-11 Solder, Sleeve

(120-150-14)

1 160-032-04C Electrical Installation, Consisting of:

1 A10099 Band, EMI

(20-108-1)

1 20-036-24-20N Braid

1 130-045-30R-4-0-4 Sleeving

08 DEC 2004 3-33

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-113 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-575-200-101 (Cont) Modification - Tail Rotor Authority, Consisting of:

1 206-575-200-111 (Cont) Modification - Electrical Installation, Consisting of:

1 160-032-04C (Cont) Electrical Installation, Consisting of:

1 130-053-1-0-20 Sleeving

1 202D121-4/86 Shrink Boot

2 XTPA-080 Meltable Tape

1 31-065-9B1J1 Decal

1 31-065-9TB1 Decal

1 33-001-002-1-08 Support Installation

1 33-001-107C Support Installation

8 oz. 299-947-100, Type II, CL 4 Adhesive (C-311)

(227 g)

1 206-575-200-113 Cable Assembly, Consisting of:

1 D38999/20WB35SN Connector

1 ETC-A1A1204X Backshell
(ETC-A1A1204H)

1 MS25036-103 Terminal

1 MS25036-149 Terminal

2 MS25036-156 Terminal Lug

1 MS3459W12S-3S Connector

AR M22759/41-12-9 Wire
(140-039-12)

AR M22759/41-22-9 Wire
(140-039-22)

1 M24308/2-4 Connector
(M24308/2-4F)

2 M24308/25-9F Screw Assembly

4 M39029/1-101 Contact

29 M39029/22-191 Contact

2 M39029/30-217 Contact

13 M39029/56-348 Contact

3-34 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-113 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-575-200-101 (Cont) Modification - Tail Rotor Authority, Consisting of:

1 206-575-200-113 (Cont) Cable Assembly, Consisting of:

37 M39029/63-368 Contact

8 M83519/2-7 Shield Term

5 M83519/2-8 Shield Term

1 M85049/38-11W Strain Relief

1 M85049/48-2-4F Backshell

AR M85485/12-22T2A Cable
(30-279-22-2)

10 030-01107-0000 Terminal

1 100-2020S Contact
(M39029/35-274)

1 130-053-4-0-48 Sleeving

AR 30-231-22D1 Cable
(30-286-22-1)

AR 30-231-22D2 Wire
(30-284-22-2)

4 MS35214-28 Screw

1 407-030-845-101 Weight Installation, Consisting of:

1 407-030-845-115 Weight

1 407-030-845-117 Weight

4 MS21042L08 Nut

2 MS27039-0833 Screw

2 MS27039-0834 Screw

2 MS27039-0836 Screw

4 NAS1149DN832J Washer

8 oz. (227 g) MIL-PRF-81733 Sealant (C-392)

1 MS14145L4 Nut

1 MS24665-151 Cotter Pin

2 NAS1149DO432K Washer

2 NAS6604D20 Bolt

08 DEC 2004 3-35

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-113 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

AR MIL-PRF-81733 Sealant (C-392)

1 BHT-206L4-FMS-19 Flight Manual Supplement

1 BHT-206-SI-2054 Service Instruction

NOTE:

1 The hub and blade assembly supplied in kit will be assembled and balanced. Parts within the hub and blade
assembly are for field reference only.

3-36 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

3-5. KIT INVENTORY (206-704-722-117) Some items of this kit may be shipped
pre-assembled. All modifications required
Part numbers in parentheses ( ) are alternate or for field installation of this kit will be
superseding part numbers. annotated with flagnotes.

NOTE
Common hardware packed with kit may
vary from that in following parts list.

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-117 Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-020-110-103 Tail Skid Assembly, Consisting of:

1 206-020-110-117 Skid

AR TUBEBORIUM Tube

1 206-501-007-101 Modification - Directional Control System, Tail

Rotor Improvement, Consisting of:

1 206-501-007-105 Bellcrank Sub-Assembly, Consisting of:

1 206-001-820-101 Bellcrank Assembly

1 206-001-821-101 Bellcrank Assembly

1 206-301-052-103 Actuator Assembly

4 AN960JD416 Washer
(NAS1149D0463J)

1 AN960JD416L Washer
(NAS1149D0416J)

1 MS14144L4 Nut
(RME9868-4)

1 MS14145L4 Nut

48 inches MS20995C41 Lockwire (C-447)

(1219 mm) (AS100029)

2 MS24665-155 Cotter Pin

1 NAS6604D13 Bolt

1 NAS6604D20 Bolt

1 NAS6604H12 Bolt

2 120-032-16-8 Shim

1 206-001-097-101 Tube Assembly

1 206-001-822-101 Idler Assembly

08 DEC 2004 3-37

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-117 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-501-007-101 (Cont) Modification - Directional Control System, Tail

Rotor Improvement, Consisting of:

1 206-001-823-101 Link Assembly

1 206-001-824-101 Bellcrank Assembly

1 206-001-825-101 Support Assembly

6 AN960JD10L Washer
(NAS1149D0332J)

13 AN960JD416 Washer
(NAS1149D0463J)

1 AN960JD416L Washer
(NAS1149D0416J)

2 AN960JD516 Washer
(NAS1149D0563J)

2 AN960JD616L Washer
(NAS1149D0616J)

5 MS14144L4 Nut
(RME9868-4)

1 MS14144L5 Nut
(RME9868-5)

1 MS14144L6 Nut
(RME9868-6)

10 ft (3 m) MS20995C32 Lockwire (C-405)

(AS100028)

5 MS21042L3 Nut

7 MS24665-155 Cotter Pin

1 MS24665-302 Cotter Pin

1 MS27039-1-12 Screw

1 NAS6603-5 Bolt

1 NAS6604D12 Bolt

1 NAS6604D15 Bolt

1 NAS6604D21 Bolt

1 NAS6604D23 Bolt

1 NAS6604D24 Bolt

3-38 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-117 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-501-007-101 (Cont) Modification - Directional Control System, Tail

Rotor Improvement, Consisting of:

2 NAS6604H4 Bolt

1 NAS6605D13 Bolt

1 NAS6606D38 Bolt

3 100-048-6-7 Pin

4 120-032-16-8 Shim

1 120-032-16-10 Shim

1 140-002-2 Washer

1 oz. (28 g) 299-947-100, Type II, CL 2 Adhesive (C-317)

1 1 206-510-003-109 Modification - Tail Rotor, Consisting of:

1 206-011-726-005 Bushing

2 206-011-741-101 Lever Assembly

1 206-011-749-113 Hub and Blade Assembly, Consisting of:

1 206-011-749-115 Hub Assembly

4 206-011-750-103 Support

REF 206-210-100-101 T/R Bal Set

(T101280-111)

REF 206-210-100-103 T/R Bal Adapter

8 212-010-710-109 Weight

16 212-010-710-111 Weight

2 400-016-100-109 Blade Assembly

(400-016-100-113)

2 406-012-108-101 Pitch Horn Assembly

20 AN960-416 Washer
(NAS1149F0463P)

8 AN960-616 Washer
(NAS1149F0663P)

8 AN960-616L Washer
(NAS1149F0632P)

6 AN970-4 Washer

08 DEC 2004 3-39

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-117 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 1 206-510-003-109 (Cont) Modification - Tail Rotor, Consisting of:

1 206-011-749-113 (Cont) Hub and Blade Assembly, Consisting of:

12 AN970-6 Washer

4 MS14144L4 Nut
(RME9868-4)

4 MS14144L6 Nut
(RME9868-6)

2 MS21042L4 Nut

4 MS21042L5 Nut

4 MS24665-132 Cotter Pin

4 MS24665-283 Cotter Pin

(MS24665-285)

2 NAS6204-1 Bolt

4 NAS6204-29D Bolt

2 NAS6204-3 Bolt

2 NAS6204-5 Bolt

2 NAS6204-7 Bolt

2 NAS6204-9 Bolt

4 NAS6605-15 Bolt

4 NAS6605-16 Bolt

4 NAS6605-17 Bolt

2 NAS6606D30 Bolt

2 NAS6606D31 Bolt

2 NAS6606D32 Bolt

2 NAS6606D34 Bolt

4 NAS6606D36 Bolt

2 NAS6606D37 Bolt

4 NAS6606D38 Bolt

2 NAS6606D39 Bolt

8 140-007-25-22C4 Washer

3-40 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-117 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 1 206-510-003-109 (Cont) Modification — Tail Rotor, Consisting of:

1 206-011-751-101 Rod Assembly

1 206-011-752-101 Flapping Stop

1 406-012-104-103 Plate

1 406-012-110-101 Spacer

1 406-012-113-101 Nut
1 406-012-118-101 Tube Assembly

1 406-012-127-101 Idler Assembly

1 406-312-102-101 Sliding Seal

2 406-312-103-101 Pitch Link

1 406-312-106-101 Tail Rotor Boot

1 407-012-105-101 Crosshead

4 AN3H7A Bolt

4 AN960-10L Washer
(NAS1149F0332P)

14 AN960-416 Washer
(NAS1149F0463P)

2 AN960-416L Washer
(NAS1149F0432P)
1 AN960-616L Washer
(NAS1149F0632P)

1 AN960-816 Washer
(NAS1149F0863P)

2 AN960PD416 Washer
(NAS1149D0463J)

6 MS14144L4 Nut
(RME9868-4)

1 MS14145L6 Nut

1 MS14145L8 Nut
10 feet MS20995C32 Lockwire (C-405)
(3 m) (AS100028)

3 MS21042L4 Nut

ECCN EAR99 9 JUN 2011 Rev. 2 3-41

FOR BEST VALUE, BUY GENUINE BELL PARTS
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-117 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 1 206-510-003-109 (Cont) Modification - Tail Rotor, Consisting of:

6 MS24665-155 Cotter Pin

1 MS24665-289 Cotter Pin

1 MS24665-306 Pin

3 NAS1197-416 Washer

2 NAS577-4A Nut
(NAS577B4A)
2 NAS578-4B Retainer

2 NAS6604D14 Bolt

1 NAS6604D15 Bolt

1 NAS6604D21 Bolt

1 NAS6604D31 Bolt

1 NAS6604D32 Bolt

2 NAS6604H22 Bolt

2 NAS6604H3 Bolt

1 2-38N141-7 Seal O-ring

(AS3209-038)

6 oz. (170 g) MIL-C-16173, Grade 2 Corrosion Preventive Compound (C-104)

6 oz. (170 g) MIL-C-16173, Grade 1 Corrosion Preventive Compound (C-101)

8 oz. (227 g) MIL-G-81322 Grease (C-001)

6 oz. (170 g) MIL-S-8802 Adhesive (C-308)

1 206-530-123-103 Modification - Fuselage Assembly, Consisting of:

1 206-023-133-101 Doubler Assembly

1 206-230-100-101 Work Aid

1 206-530-123-107 Support Assembly

1 206-530-123-121 Doubler

2 206-530-123-123 Splice Angle

1 206-530-123-125 Bracket

2 MS20426AD3-4 Rivet

4 MS20470AD4-4 Rivet

3-42 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-117 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-530-123-103 (Cont) Modification - Fuselage Assembly, Consisting of:

8 MS20470AD4-5 Rivet

1 MS21059L3 Nutplate

17 M7885/2-4-02 Rivet
(NAS9301B-4-02)

4 M7885/2-4-03 Rivet
(NAS9301B-4-03)

1 M7885/3-4-02 Rivet
(NAS9302B-4-02)

13 M7885/6-4-02 Rivet
(NAS9304B-4-02)

38 M7885/6-4-03 Rivet
(NAS9304B-4-03)

2 M7885/6-4-04 Rivet
(NAS9304B-4-04)

5 NAS1097AD4-4 Rivet

2 100-050B250 Plug Button

1 100-088-1 Identification Plate

(100-088-2)

3.5 oz. 299-947-100, Type II, CL 2 Adhesive (C-317)

(100 g)

36 inches 299-947-110, Type II Tape, 1 inch (25.4 mm) width (C-454)

(915 mm)

4 oz. (113 g) MIL-PRF-81733 Sealant (C-392)

1 206-540-004-101 Modification - Drive System Installation Consisting

of:

1 206-540-005-101 Modification - Gearbox Assembly, Tail Rotor

Consisting of:

1 206-040-949-101 Shaft

1 MS24665-227 Cotter Pin

1 M83248/1-244 Packing
(AS3209-244)

1 29800-8054 Wear Sleeve

(536827)
(206-340-401-101)

08 DEC 2004 3-43

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-117 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-540-004-101 (Cont) Modification - Drive System Installation Consisting

of:

1 206-540-005-101 (Cont) Modification - Gearbox Assembly, Tail Rotor,

Consisting of:

1 100-024-1 Identification Plate

(100-140-2)

2 oz. 299-947-100, Type II, CL 2 Adhesive (C-317)

(57 g)

8 oz. MIL-G-81322 Grease (C-001)

(227 g)

8 oz. MIL-S-8784 Sealing Compound (C-328)

(227 g)

1 206-575-200-101 Modification - Tail Rotor Authority, Consisting of:

1 206-075-798-101 Decal

1 206-075-799-101 Plate

1 206-575-200-103 Modification - Panel Assembly, Consisting of:

1 25-0195-3269 Filter

1 206-575-200-105 Modification - Shell Assembly, Consisting of:

1 206-575-200-115 Doubler

1 AN960JD716L Washer
(NAS1149D0716J)

1 MS28034-3 Temperature Bulb

1 MS35333-121 Lock Washer

1 MS35691-29 Nut

1 31-065-9E1 Decal

8 oz. MIL-PRF-81733 Sealant (C-392)

(227 g)

8 oz. 299-947-100, Type II, CL 2 Adhesive (C-317)

(227 g)

1 206-575-200-107 Modification - Overhead Panel, Consisting of:

1 MS26574-1-1/2 Circuit breaker

1 31-026-1353H12 Decal

3-44 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-117 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-575-200-101 (Cont) Modification - Tail Rotor Authority, Consisting of:

1 206-575-200-107 (Cont) Modification - Overhead Panel, Consisting of:

1 31-026-527H12 Decal

1 206-575-200-109 Modification - Console, Consisting of:

1 206-074-124-111 Control Panel Assembly

(206-074-124-113)

4 MS35215-56 Screw

1 206-575-200-111 Modification - Electrical Installation, Consisting of:

3 AN960JD10L Washer
(NAS1149D0332J)

4 AN960JD4L Washer
(NAS1149DN416J)

3 MS21042L3 Nut

2 MS21919WDG4 Clamp

6 MS25281-R9 Clamp

2 MS27039-1-06 Screw

1 MS27039-1-07 Screw

50 MS3367-1-9 Strap, Tie

4 MS35206-215 Screw

2 MS35489-12 Grommet

1 MS9592-012 Bracket

2 M81714/60-22-05 Terminal Module

1 M85528/2-12A01 Mounting Flange

(M85049/95-12A-A)

1 CTJ-3A-02 Rail Assembly

1 120-150-11 Solder, Sleeve

(120-150-14)

1 160-032-04C Electrical Installation, Consisting of:

1 A10099 Band, EMI

(20-108-1)

1 20-036-24-20N Braid

1 130-045-30R-4-0-4 Sleeving

08 DEC 2004 3-45

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-117 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-575-200-101 (Cont) Modification - Tail Rotor Authority, Consisting of:

1 206-575-200-111 (Cont) Modification - Electrical Installation, Consisting of:

1 160-032-04C (Cont) Electrical Installation, Consisting of:

1 130-053-1-0-20 Sleeving

1 202D121-4/86 Shrink Boot

2 XTPA-080 Meltable Tape

1 31-065-9B1J1 Decal

1 31-065-9TB1 Decal

1 33-001-002-1-08 Support Installation

1 33-001-107C Support Installation

8 oz. 299-947-100, Type II, CL 4 Adhesive (C-311)

(227 g)

1 206-575-200-113 Cable Assembly, Consisting of:

1 D38999/20WB35SN Connector

1 ETC-A1A1204X Backshell
(ETC-A1A1204H)

1 MS25036-103 Terminal

1 MS25036-149 Terminal

2 MS25036-156 Terminal Lug

1 MS3459W12S-3S Connector

AR M22759/41-12-9 Wire
(140-039-12)

AR M22759/41-22-9 Wire
(140-039-22)

1 M24308/2-4 Connector
(M24308/2-4F)

2 M24308/25-9F Screw Assembly

4 M39029/1-101 Contact

29 M39029/22-191 Contact

2 M39029/30-217 Contact

13 M39029/56-348 Contact

3-46 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS
 BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-117 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

1 206-575-200-101 (Cont) Modification - Tail Rotor Authority, Consisting of:

1 206-575-200-113 (Cont) Cable Assembly, Consisting of:

37 M39029/63-368 Contact

8 M83519/2-7 Shield Term

5 M83519/2-8 Shield Term

1 M85049/38-11W Strain Relief

1 M85049/48-2-4F Backshell

AR M85485/12-22T2A Cable
(30-279-22-2)

10 030-01107-0000 Terminal

1 100-2020S Contact
(M39029/35-274)

1 130-053-4-0-48 Sleeving

AR 30-231-22D1 Cable
(30-286-22-1)

AR 30-231-22D2 Wire
(30-284-22-2)

4 MS35214-28 Screw

1 407-030-845-101 Weight Installation, Consisting of:

1 407-030-845-115 Weight

1 407-030-845-117 Weight

4 MS21042L08 Nut

2 MS27039-0833 Screw

2 MS27039-0834 Screw

2 MS27039-0836 Screw

4 NAS1149DN832J Washer

8 oz. (227 g) MIL-PRF-81733 Sealant (C-392)

1 MS14145L4 Nut

1 MS24665-151 Cotter Pin

2 NAS1149DO432K Washer

2 NAS6604D20 Bolt

08 DEC 2004 3-47

GENUINE BELL PARTS ARE YOUR BEST VALUE
BHT-206-SI-2054

QUANTITY PART NUMBER NOMENCLATURE

1 206-704-722-117 (Cont) Auxiliary Equipment Kit, Directional Control

System, Tail Rotor Improvement, Consisting of:

AR MIL-PRF-81733 Sealant (C-392)

1 BHT-206L4-FMS-19 Flight Manual Supplement

1 BHT-206-SI-2054 Service Instruction

NOTE:

1 The hub and blade assembly supplied in kit will be assembled and balanced. Parts within the hub and blade
assembly are for field reference only.

3-48 08 DEC 2004

FOR BEST VALUE, BUY GENUINE BELL PARTS