Leonardo S.p.A.

Via Giovanni Agusta, 520

21017 Cascina Costa di Samarate (VA) Italy
Tel.: +39 0331 229111 - Fax: +39 0331 229605/222595

SERVICE BULLETIN
N° 139-616
RECOMMENDED DATE:
REV. :
June 19, 2024
/

TITLE
ATA 53 - LOWER LH TAIL LONGERON INSPECTION AND REPAIR

REVISION LOG
First Issue

An appropriate entry should be made in the aircraft log book upon accomplishment.
If ownership of aircraft has changed, please, forward to new owner.

Page 1 of 35
 1. PLANNING INFORMATION

A. EFFECTIVITY
Part I:
Tail boom assemblies P/N 3G5350A00132, P/N 3G5350A00133, P/N 3G5350A00134,
P/N 3G5350A00135 and P/N 3G5350A00136 up to S/N PZL247C included, installed
on AB139/AW139 helicopters or kept in stock, and equipped with structural provision
of the Kit HF P/N 3G2310F00211.
Part II:
Tail boom assemblies P/N 3G5350A00132, P/N 3G5350A00133, P/N 3G5350A00134
and P/N 3G5350A00135:
 identified as affected and requiring Part II application based on inspection in
Part I, and
 already improved by tail fitting reinforcement retromod P/N 3G5309P02711
(ref. also to SB 139-419) or tail reinforcement retromod P/N 3G5309P01812
(ref. also to SB 139-200).
Part III:
Tail boom assemblies P/N 3G5350A00132, P/N 3G5350A00133 and
P/N 3G5350A00134:
 identified as affected and requiring Part III application based on inspection in
Part I, and
 NOT already improved by tail fitting reinforcement retromod P/N 3G5309P02711
(ref. also to SB 139-419) or tail reinforcement retromod P/N 3G5309P01812
(ref. also to SB 139-200).
Part IV:
Tail boom assembly P/N 3G5350A00136 up to S/N PZL247C, identified as affected
and requiring Part IV application based on inspection in Part I.

B. COMPLIANCE
Part I
 For tail boom assemblies installed on AB139/AW139 helicopters: within and not later
than 6 months after the issue of this Service Bulletin.
 For tail boom assemblies kept in stock: before next installation.
Part II, Part III, Part IV
Within and not later than 600 flight hours or 1 year whichever occurs first after
accomplishment of Part I.

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
Page 2 of 35 REVISION: /
 C. CONCURRENT REQUIREMENTS
N.A.

D. REASON
This Service Bulletin is issued in order to provide the necessary instructions on how to
inspect the lower left longeron for drill marks and, in case of findings, on how to apply
a repair procedure.

LHD issued this SB for the following reason:

Helicopter Reliability/Maintainability ✔

Product Improvement

Obsolescence

Customization

Product/Capability Enhancement

E. DESCRIPTION
During 300 FH inspection, an operator found drill marks in two locations on the lower
left tail boom longeron where the HF mount is fitted to the tail boom at STA 9200,
WL 1670, BL 300 LH. For in service components, repair drawings have been developed
to install reinforcements in the affected area.
Part I provides the necessary instructions on how to perform a one-off check for the
presence of drill marks on the longeron.
Part II provides the necessary instructions on how to perform the installation of the tail
lower LH longeron HF antenna repair P/N 3G5350R00911.
Part III provides the necessary instructions on how to perform the installation of the tail
lower LH longeron HF repair P/N 3G5350R01011.
Part IV provides the necessary instructions on how to perform the installation of the tail
lower LH longeron HF antenna repair P/N 3G5350R00811.

F. APPROVAL
The technical content of this Service Bulletin is approved under the authority of DOA
nr. EASA.21.J.005. For helicopters registered under other Aviation Authorities, before
applying the Service Bulletin, applicable Aviation Authority approval must be checked
within Leonardo Helicopters customer portal.

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
REVISION: / Page 3 of 35
 EASA states mandatory compliance with inspections, modifications or technical
directives and related time of compliance by means of relevant Airworthiness
Directives.
If an aircraft listed in the effectivity embodies a modification or repair not LHD certified
and affecting the content of this Service Bulletin, it is responsibility of the
Owner/Operator to obtain a formal approval by Aviation Authority having jurisdiction on
the aircraft, for any adaptation necessary before incorporation of the present Service
Bulletin.

G. MANPOWER
To comply with this Service Bulletin, the following MMH are deemed necessary.
Part I: approximately ten (10);
Part II: approximately thirty-five (35);
Part III: approximately thirty-five (35);
Part IV: approximately thirty-five (35).
MMH are based on hands-on time and can change with helicopter configuration,
personnel and facilities available. MMH are not comprehensive of the overall hours
necessary to get access to work areas and to remove all the equipment that interferes
with the application of the prescribed instructions.

H. WEIGHT AND BALANCE

N.A.

I. REFERENCES

I.1 PUBLICATIONS
Following Data Modules refer to AMP:
DATA MODULE DESCRIPTION PART
DM01 39-A-00-20-00-00A-120A-A Helicopter on ground for a safe I
maintenance
DM02 39-A-06-41-00-00A-010A-A Access doors and panels - All
General data
DM03 39-A-23-14-04-00A-520A-K HF antenna - Remove I
procedure
DM04 39-A-23-14-04-00A-720A-K HF antenna - Install procedure All

I.2 ACRONYMS & ABBREVIATIONS

AMDI Aircraft Material Data Information
AMP Aircraft Maintenance Publication

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
Page 4 of 35 REVISION: /
 AR As Required
DM Data Module
DOA Design Organization Approval
EASA European Aviation Safety Agency
FW Forward
IPD Illustrated Part Data
ITEP Illustrated tool and equipment publication
LH Left Hand
LHD Leonardo Helicopters Division
MMH Maintenance Man Hours
N.A. Not Applicable
P/N Part Number
SB Service Bulletin
S/N Serial Number

I.3 ANNEX
N.A.

J. PUBLICATIONS AFFECTED
N.A.

K. SOFTWARE ACCOMPLISHMENT SUMMARY

N.A.

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
REVISION: / Page 5 of 35
 2. MATERIAL INFORMATION

A. REQUIRED MATERIALS

A.1 PARTS

PART I

N.A.

PART II
# P/N ALTERNATIVE P/N DESCRIPTION Q.TY LVL NOTE LOG P/N
TAIL LOWER LH
1 3G5350R00911 LONGERON HF ANTENNA REF . -
REPAIR
2 3G5350R00951 Shim angle 1 .. (1) -
3 3G5350R00953 3G5350R00952 Reinforcement angle 1 .. (2)(3) -
4 NAS9301BNS-6-04 NAS9301B-6-04 Rivet 9 .. (4) -
5 NAS9302BNS-5-02 NAS9302B-5-02 Rivet 2 . -
6 MS90353S0503 Rivet 5 . -
7 NAS9302BNS-6-04 NAS9302B-6-04 Rivet 4 . -
8 3G5350A18954 3G5350A18954A Lower left machined (down) 1 . (5) -
Lower laminated shim -
9 3G5350A19454 3G5350A19454A 1 . (5)
(down)
10 3G5350A19754 3G5350A19754A Lower longeron strip (down) 1 . (5) -
11 NAS9301BNS-6-03 NAS9301B-6-03 Rivet 12 . (5) -
12 NAS9301BNS-6-05 NAS9301B-6-05 Rivet 11 . (5) -
13 A297A06TW13 Rivet 4 . (5) -

PART III
# P/N ALTERNATIVE P/N DESCRIPTION Q.TY LVL NOTE LOG P/N
TAIL LOWER LH
14 3G5350R01011
LONGERON HF REPAIR
REF . -

15 3G5350R01051 Shim angle 1 .. (6) -

16 3G5350R01052 Reinforcement angle 1 .. (7) -
17 NAS9301BNS-6-04 NAS9301B-6-04 Rivet 16 .. -
18 NAS9302BNS-5-02 NAS9302B-5-02 Rivet 2 . -
19 NAS9302B-6-04 Rivet 14 . -

PART IV
# P/N ALTERNATIVE P/N DESCRIPTION Q.TY LVL NOTE LOG P/N
TAIL LOWER LH
20 3G5350R00811 LONGERON HF ANTENNA REF . -
REPAIR
21 3G5350R00851 Shim angle 1 .. (8) -
22 3G5350R00852 Reinforcement angle 1 .. (9) -
23 A297A06TW03 Rivet 12 .. -
24 A299A06TW04 Rivet 7 .. -
25 A299A06TW05 Rivet 6 .. -
26 AGS4720-508 NAS1721H5L2A Rivet 2 . -

Refer also to IPD for the spares materials required to comply with the AMP DMs
referenced in the accomplishment instructions.

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
Page 6 of 35 REVISION: /
 A.2 CONSUMABLES
The following consumable materials, or equivalent, are necessary to accomplish
this Service Bulletin:
# SPEC./LH CODE NUMBER DESCRIPTION Q.TY NOTE PART
Sheet AL-ALY 2024 T3 2
27 AMS-QQ-A-250/4 0,02 m (1) II
Thickness 1,02 mm
Sheet AL-ALY 2024 T3
28 AMS-QQ-A-250/4 0,1 m2 (2) II
Thickness 2 mm
Sheet AL-ALY 2024 T3
29 AMS-QQ-A-250/4 0,02 m2 (6) III
Thickness 1,02 mm
Sheet AL-ALY 2024 T3
30 AMS-QQ-A-250/4 0,1 m2 (7) III
Thickness 2 mm
Sheet AL-ALY 2024 T3
31 AMS-QQ-A-250/4 0,01 m2 (8) IV
Thickness 0,4 mm
Sheet AL-ALY 2024 T0
32 AMS-QQ-A-250/4 0,2 m2 (9) IV
Thickness 2 mm
MMM-A-132, Type II, Class 2 Adhesive EA9309.3NA II, III,
33 AR (10)
199-05-002 Type I, Class 2 (C021) IV
Code II, III,
34 Liquid shim EA9395 AR (10)
No. 999999999000000773 IV

Refer also to AMDI for the consumable materials required to comply with the AMP DMs
referenced in the accomplishment instructions.

A.3 LOGISTIC MATRIX

N.A.

NOTES
(1) Shim angle P/N 3G5350R00951 can be obtained from raw material with following
properties: sheet AL-ALY 2024 T3 Thickness 1.02 mm (ref. to Figure 6).
(2) Reinforcement angle P/N 3G5350R00953 can be obtained from raw material with
following properties: Sheet AL-ALY 2024 T3 Thickness 2 mm (ref. to Figure 5).
(3) Reinforcement angle P/N 3G5350R00953 can be obtained from rework of
reinforcement angle P/N 3G5350R00952.
(4) Qty 12 additional rivets P/N NAS9301BNS-6-04 or NAS9301B-6-04 are required if
drill mark has been found at location 2 during the inspection in Part I.
(5) This item has to be provided only if the drill mark has been found at location 2 during
the inspection in Part I.
(6) Shim angle P/N 3G5350R01051 can be obtained from raw material with following
properties: sheet AL-ALY 2024 T3 Thickness 1.02 mm (ref. to Figure 15).
(7) Reinforcement angle P/N 3G5350R01052 can be obtained from raw material with
following properties: Sheet AL-ALY 2024 T3 Thickness 2 mm (ref. to Figure 16).
(8) Shim angle P/N 3G5350R00851 can be obtained from raw material with following
properties: sheet AL-ALY 2024 T3 Thickness 0,4 mm (ref. to Figure 11).

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
REVISION: / Page 7 of 35
 (9) Reinforcement angle P/N 3G5350R00852 can be obtained from raw material with
following properties: sheet AL-ALY 2024 T0 Thickness 2 mm (ref. to Figure 10).
(10) Item to procured as local supply.

B. SPECIAL TOOLS
The following special tools, or equivalent, are necessary to accomplish this Service
Bulletin:
# P/N DESCRIPTION Q.TY NOTE PART
35 Commercial Boroscope 1 I

Refer also to ITEP for the special tools required to comply with the AMP DM referenced
in the accomplishment instructions.

C. INDUSTRY SUPPORT INFORMATION

Owners/Operators who comply with the instructions of this Service Bulletin no later than
the applicable date in the “Compliance” section will be eligible to receive necessary
replacements on free of charge basis.
Consumables, Special Tools, and materials required by AMP DM recalled in this SB
are not included in the aforementioned policy.
NOTE: Customers who fail to comply with the instructions in this Service Bulletin before
the compliance date are not eligible for the aforementioned special policy.
Please Issue relevant MMIR form to your Warranty Administration Dpt. only if damage
is found following the inspection prescribed in Part I and so if Part II, Part III or Part IV
application is required.

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
Page 8 of 35 REVISION: /
 3. ACCOMPLISHMENT INSTRUCTIONS

GENERAL NOTES
a) Place an identification tag on all components that
are re-usable, including the attaching hardware that
has been removed to gain access to the modification
area and adequately protect them until their later re-
use.
b) Exercise extreme care during drilling operations to
prevent instruments, cables and hoses damage.
c) After drilling, remove all swarf and sharp edges.
Apply on bare metal a light film of primer unless the
hole is used for ground connection.
d) Let adhesive cure at room temperature for at least
24 hours unless otherwise specified.
e) Exposed thread surface and nut must be protected
using a layer of tectyl according to MIL-C-16173
grade I.
f) All lengths are in mm.

PART I

NOTE
Skip steps 1 and 2 if the tail boom assembly is kept in
stock.
1. In accordance with AMP DM 39-A-00-20-00-00A-120A-A, prepare the helicopter on
ground for a safe maintenance. Disconnect the battery, all electrical power sources and/or
the external power supply.

NOTE
As alternative to HF antenna removal it is allowed to
gain access through the access panel 310BL
(Ref. AMP DM 39-A-06-41-00-00A-010A-A).
2. In accordance with AMP DM 39-A-23-14-04-00A-520A-K, if necessary, remove
HF antenna from the helicopter.

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
REVISION: / Page 9 of 35
 NOTE
Refer to Figures 12 and 13 for tail boom assemblies
P/N 3G5350A00132/-133/-134.
Refer to Figures 1 and 2 for tail boom assembly
P/N 3G5350A00135.
Refer to Figures 7 and 8 for tail boom assembly
P/N 3G5350A00136.
3. With reference to Figures 1 and 2 Detail A or Figures 7 and 8 Detail A or Figures 12 and
13 Detail A, perform a visual inspection to find drill marks on the internal side of the
longeron in correspondence of the indicated rivets (location 1 and 2) as described in the
following procedure:
3.1 With reference to Figure 2 Detail A or Figure 8 Detail A or Figure 13 Detail A, insert
the boroscope inside the tail boom assy longeron passing through the hole on the
FW cover LH or passing through the access panel 310BL.
3.2 Accurately examine the internal areas of the lower left longeron in correspondence
of the indicated rivets at locations 1 and 2 for presence of drill marks. In case of
findings, accomplishment of Part II or Part III or Part IV is required within the
compliance time indicated; otherwise, no other action is needed after Part I
accomplishment.
4. Record the compliance with Part I of this Service Bulletin on the component log card.

NOTE
Skip steps 5 thru 7 if the tail boom assembly is kept in
stock.
5. In accordance with AMP DM 39-A-06-41-00-00A-010A-A, if necessary re-install all
external panels, internal panels and internal liners previously removed as required.
6. In accordance with AMP DM 39-A-23-14-04-00A-720A-K, if necessary, re-install
HF antenna on the helicopter.
7. Return the helicopter to flight configuration and record for compliance with Part I of this
Service Bulletin on the helicopter logbook.
8. Gain access to My Communications section on Leonardo WebPortal and compile the
“Service Bulletin Application Communication”.
As an alternative, send the attached compliance form to the following mail box:
engineering.support.lhd@leonardo.com
and (for North, Central and South America) also to:
AWPC.Engineering.Support@leonardocompany.us

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
Page 10 of 35 REVISION: /
 PART II

NOTE
Perform the following step 1 only if shim angle
P/N 3G5350R00951 has not been provided.
1. With reference to Figure 6, rework one plate AL-ALY 2024 (Thickness 1.02 mm) as
indicated to obtain shim angle and mark it as P/N 3G5350R00951.

NOTE
Perform the following step 2 only if reinforcement angle
P/N 3G5350R00952 has been provided.
2. With reference to Figure 5, rework the reinforcement angle P/N 3G5350R00952 as
indicated and mark it as P/N 3G5350R00953.

NOTE
Perform the following step 3 only if reinforcement angle
P/N 3G5350R00952 or P/N 3G5350R00953 has not
been provided.
3. With reference to Figure 5, rework one plate AL-ALY 2024 (Thickness 2.00 mm) as
indicated to obtain reinforcement angle and mark it as P/N 3G5350R00953.

NOTE
Skip the following step 4 if the tail boom assembly is kept
in stock.
4. In accordance with AMP DM 39-A-06-41-00-00A-010A-A and with reference to Figure 1,
remove all external panels, internal panels and internal liners as required to gain access
to the area affected by the installation.

NOTE
The tail boom can be lifted with a sling (support
equipment HA-09-00 or HA-16-02). Equivalent solutions
(different sling, saddles at STA10630 and STA11370)
can be used.

NOTE
Perform the following step 5 ONLY if the drill mark has
been found at location 2 (Ref. Figure 2 Detail A).
5. With reference to Figure 2 Section B-B, remove lower left machined P/N 3G5350A18954,
shim down P/N 3G5350A19454 and strip down P/N 3G5350A19754 from the longeron
P/N 3G5350A12851. Retain for later reuse.

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
REVISION: / Page 11 of 35
 NOTE
Repeat the following steps 6 thru 9 for each location
where drill marks have been found: location 1 AND/OR
location 2.
6. With reference to Figure 2 Detail A, drill out the indicated rivet.
7. With reference to Figure 2, in correspondence of previously removed rivet drill a hole
Ø 3.25 normal to external profile on the longeron P/N 3G5350A12851 as indicated.
8. With reference to Figure 3 View C, from the internal side of the tail boom assy, widen the
previously performed slotted hole up to Ø 10.0 only on the longeron.
9. With reference to Figure 2 Detail A, install rivet P/N NAS9302BNS-5-02 on the doubler
P/N 3G5350A20351.

NOTE
Perform the following step 10 ONLY if drill mark has
been found at location 2 (Ref. Figure 2 Detail A).

NOTE
If necessary, it is allowed to use oversized hardware.
10. With reference to Figure 4, re-install lower left machined P/N 3G5350A18954, shim down
P/N 3G5350A19454 and strip down P/N 3G5350A19754 by means of n°12 rivets
P/N NAS9301BNS-6-04, n°12 rivets P/N NAS9301BNS-6-03 or P/N NAS9301B-6-03,
n°4 rivets P/N A297A06TW13 and n°11 rivets P/N NAS9301BNS-6-05 or
P/N NAS9301B-6-05 on the longeron P/N 3G5350A12851.
11. With reference to Figure 3 View E, drill out the indicated existing rivets.
12. With reference to Figure 3 View E, temporarily locate the shim angle P/N 3G5350R00951
and the reinforcement angle P/N 3G5350R00953 and proceed as follows:
12.1 Countermark on the shim angle the positions of existing rivets previously removed
at step 11 and the positions of existing holes of the reinforcement angle.
12.2 Countermark on the reinforcement angle the positions of existing rivets previously
removed at step 11.
12.3 Countermark on the longeron the positions of existing holes of the reinforcement
angle.
12.4 Drill pilot holes Ø2.50 through the shim angle, the reinforcement angle and the
longeron in the previously countermarked positions.

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
Page 12 of 35 REVISION: /
 NOTE
During installation of shim angle P/N 3G5350R00951
and reinforcement angle P/N 3G5350R00953, it is
allowed to use liquid shim EA9395 on the banding area
to fill possible gap.
13. With reference to Figure 3 Section D-D, install shim angle P/N 3G5350R00951 by means
of adhesive EA9309.3NA (C021) on the longeron P/N 3G5350A12851.

NOTE
If necessary, it is allowed to use oversized hardware.
14. With reference to Figure 3, install reinforcement angle P/N 3G5350R00953 by means of
adhesive EA9309.3NA (C021), n°5 rivets P/N MS90353S0503, n°4 rivets
P/N NAS9302BNS-6-04 or P/N NAS9302B-6-04 and n°9 rivets P/N NAS9301BNS-6-04.
15. Record the compliance with Part II of this Service Bulletin on the component log card.

NOTE
Skip steps 16 thru 18 if the tail boom assembly is kept
in stock.
16. In accordance with AMP DM 39-A-06-41-00-00A-010A-A, re-install all external panels,
internal panels and internal liners previously removed as required.
17. In accordance with AMP DM 39-A-23-14-04-00A-720A-K, if necessary, re-install
HF antenna on the helicopter.
18. Return the helicopter to flight configuration and record for compliance with Part II of this
Service Bulletin on the helicopter logbook.
19. Gain access to My Communications section on Leonardo WebPortal and compile the
“Service Bulletin Application Communication”.
As an alternative, send the attached compliance form to the following mail box:
engineering.support.lhd@leonardo.com
and (for North, Central and South America) also to:
AWPC.Engineering.Support@leonardocompany.us

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
REVISION: / Page 13 of 35
 PART III

NOTE
Perform the following step 1 only if shim angle
P/N 3G5350R01051 has not been provided.
1. With reference to Figure 15, rework one plate AL-ALY 2024 (Thickness 1.02 mm) as
indicated to obtain shim angle and mark it as P/N 3G5350R01051.

NOTE
Perform the following step 2 only if reinforcement angle
P/N 3G5350R01052 has not been provided.
2. With reference to Figure 16, rework one plate AL-ALY 2024 (Thickness 2.00 mm) as
indicated to obtain reinforcement angle and mark it as P/N 3G5350R01052.

NOTE
Skip the following step 3 if the tail boom assembly is kept
in stock.
3. In accordance with AMP DM 39-A-06-41-00-00A-010A-A and with reference to Figure 12,
remove all external panels, internal panels and internal liners as required to gain access
to the area affected by the installation.

NOTE
The tail boom can be lifted with a sling (support
equipment HA-09-00 or HA-16-02). Equivalent solutions
(different sling, saddles at STA10630 and STA11370)
can be used.

NOTE
Repeat the following steps 4 thru 7 for each location
where drill marks have been found: location 1 AND/OR
location 2.
4. With reference to Figure 13 Detail A, drill out the indicated rivet.
5. With reference to Figure 13, in correspondence of previously removed rivet drill a hole
Ø 3.25 normal to external profile on the longeron P/N 3G5350A12851 as indicated.
6. With reference to Figure 14 View C, from the internal side of the tail boom assy, widen the
previously performed slotted hole up to Ø 10.0 only on the longeron.
7. With reference to Figure 13 Detail A, install rivet P/N NAS9302BNS-5-02 on the doubler
P/N 3G5350A20351.
8. With reference to Figure 14 View E, drill out the indicated existing rivets.

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
Page 14 of 35 REVISION: /
 9. With reference to Figure 14 View E, temporarily locate the shim angle P/N 3G5350R01051
and the reinforcement angle P/N 3G5350R01052 and proceed as follows:
9.1 Countermark on the shim angle the positions of existing rivets previously removed
at step 8 and the positions of existing holes of the reinforcement angle.
9.2 Countermark on the reinforcement angle the positions of existing rivets previously
removed at step 8.
9.3 Countermark on the longeron the positions of existing holes of the reinforcement
angle.
9.4 Drill pilot holes Ø2.50 through the shim angle, the reinforcement angle and the
longeron in the previously countermarked positions.

NOTE
During installation of shim angle P/N 3G5350R01051
and reinforcement angle P/N 3G5350R01052, it is
allowed to use liquid shim EA9395 on the banding area
to fill possible gap.
10. With reference to Figure 14 Section D-D, install shim angle P/N 3G5350R01051 by means
of adhesive EA9309.3NA (C021) on the longeron P/N 3G5350A12851.

NOTE
If necessary, it is allowed to use oversized hardware.
11. With reference to Figure 14, install reinforcement angle P/N 3G5350R01052 by means of
adhesive EA9309.3NA (C021), n°14 rivets P/N NAS9302B-6-04 and n°16 rivets
P/N NAS9301BNS-6-04.
12. Record the compliance with Part III of this Service Bulletin on the component log card.

NOTE
Skip steps 13 thru 15 if the tail boom assembly is kept
in stock.
13. In accordance with AMP DM 39-A-06-41-00-00A-010A-A, re-install all external panels,
internal panels and internal liners previously removed as required.
14. In accordance with AMP DM 39-A-23-14-04-00A-720A-K, if necessary, re-install
HF antenna on the helicopter.
15. Return the helicopter to flight configuration and record for compliance with Part III of this
Service Bulletin on the helicopter logbook.

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
REVISION: / Page 15 of 35
 16. Gain access to My Communications section on Leonardo WebPortal and compile the
“Service Bulletin Application Communication”.
As an alternative, send the attached compliance form to the following mailbox:
engineering.support.lhd@leonardo.com
and (for North, Central and South America) also to:
AWPC.Engineering.Support@leonardocompany.us

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
Page 16 of 35 REVISION: /
 PART IV

NOTE
Perform the following step 1 only if shim angle
P/N 3G5350R00851 has not been provided.
1. With reference to Figure 11, rework one plate AL-ALY 2024 (Thickness 0.40 mm) as
indicated to obtain shim angle and mark it as P/N 3G5350R00851.

NOTE
Perform the following step 2 only if reinforcement angle
P/N 3G5350R00852 has not been provided.
2. With reference to Figure 10, rework one plate AL-ALY 2024 (Thickness 2.00 mm) as
indicated to obtain reinforcement angle and mark it as P/N 3G5350R00852.

NOTE
Skip the following step 3 if the tail boom assembly is kept
in stock.
3. In accordance with AMP DM 39-A-06-41-00-00A-010A-A and with reference to Figure 7,
remove all external panels, internal panels and internal liners as required to gain access
to the area affected by the installation.

NOTE
The tail boom can be lifted with a sling (support
equipment HA-09-00 or HA-16-02). Equivalent solutions
(different sling, saddles at STA10630 and STA11370)
can be used.

NOTE
Repeat the following steps 4 thru 8 for each locations
where drill marks have been found: location 1 AND/OR
location 2.
4. With reference to Figure 8 Detail A, drill out the indicated rivets.
5. With reference to Figure 8, in correspondence of previously removed rivet drill a hole
Ø 3.25 normal to external profile on the longeron P/N 3G5350A22551 as indicated.
6. With reference to Figure 9 View C, from the internal side of the tail boom assy, widen the
previously performed slotted hole up to Ø 10.0 only on the longeron.
7. With reference to Figure 8 Detail A, install rivet P/N AGS4720-508 on the doubler
P/N 3G5350A20351.
8. With reference to Figure 9 View E, drill out the indicated existing rivets.

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
REVISION: / Page 17 of 35
 9. With reference to Figure 3 View E, temporarily locate the shim angle P/N 3G5350R00851
and the reinforcement angle P/N 3G5350R00852 and proceed as follows:
9.1 Countermark on the shim angle the positions of existing rivets previously removed
at step 8 and the positions of existing holes of the reinforcement angle.
9.2 Countermark on the reinforcement angle the positions of existing rivets previously
removed at step 8.
9.3 Countermark on the longeron the positions of existing holes of the reinforcement
angle.
9.4 Drill pilot holes Ø2.50 through the shim angle, the reinforcement angle and the
longeron in the previously countermarked positions.

NOTE
During installation of shim angle P/N 3G5350R00851
and reinforcement angle P/N 3G5350R00852, if the
clearance to be shimmed is between 0.2 mm and
0.7 mm it is allowed to use liquid shim EA9395 on the
banding area to fill possible gap.
10. With reference to Figure 9 Section D-D, install shim angle P/N 3G5350R00851 by means
of adhesive EA9309.3NA (C021) on the longeron P/N 3G5350A22551.

NOTE
If necessary, it is allowed to use oversized hardware.
11. With reference to Figure 9, install reinforcement angle P/N 3G5350R00852 by means of
adhesive EA9309.3NA (C021), n°12 rivets P/N A297A06TW03, n°7 rivets
P/N A299A06TW04 and n°6 rivets P/N A299A06TW05.
12. Record the compliance with Part IV of this Service Bulletin on the component log card.

NOTE
Skip steps 13 thru 15 if the tail boom assembly is kept
in stock.
13. In accordance with AMP DM 39-A-06-41-00-00A-010A-A, re-install all external panels,
internal panels and internal liners previously removed as required.
14. In accordance with AMP DM 39-A-23-14-04-00A-720A-K, re-install HF antenna on the
helicopter.
15. Return the helicopter to flight configuration and record for compliance with Part IV of this
Service Bulletin on the helicopter logbook.

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
Page 18 of 35 REVISION: /
 16. Gain access to My Communications section on Leonardo WebPortal and compile the
“Service Bulletin Application Communication”.
As an alternative, send the attached compliance form to the following mailbox:
engineering.support.lhd@leonardo.com
and (for North, Central and South America) also to:
AWPC.Engineering.Support@leonardocompany.us

 Non cancellare mai questo segnalibro Non cancellare mai interruzione sezione

S.B. N°139-616 RECOMMENDED

DATE: June 19, 2024
REVISION: / Page 19 of 35
 3G5350R00911
TAIL LOWER LH LONGERON
HF ANTENNA REPAIR

Page 20 of 35
3G5350A00132 TAIL BOOM ASSY (REF)
3G5350A00133 TAIL BOOM ASSY (REF)
3G5350A00134 TAIL BOOM ASSY (REF)
STA 3G5350A00135 TAIL BOON ASSY (REF)
8701.60
REF

WL
2751.6
WL REF
2667.64
REF

Figure 1
H

STA
STA 12299.2
11358.7 REF
REF
WL
1570.01
REF
STA
10249.1 HF ANTENNA INSTALLATION
REF
A (REF)
STA
8700.1
REF

3G5309P01812 TAIL REINFORCEMENT RETRO MODIFICATION

(REF)

VIEW LOOKING INBOARD LEFT SIDE

SB139-616-005-01

S.B. N°139-616 RECOMMENDED

REVISION: /
DATE: June 19, 2024
 3G5315A15951 FW COVER LH
(REF)

3G5350A20351 DOUBLER 3G5350A16153 LEFT LOWER DOUBLER EXTERNAL

(REF) (REF)

TAIL ASSY B
(REF)

2
WL
1681.2
REF

B B REMOVE EXISTING RIVET

DRILL:
HOLE Ø3.25 NORMAL TO
REMOVE EXISTING RIVET EXTERNAL PROFILE (ONLY ON LONGERON)
DRILL: (SEE SECTION B-B)
HOLE Ø3.25 NORMAL TO REINSTALL SAME RIVET P/N NAS9302BNS-5-02
EXTERNAL PROFILE (ONLY ON LONGERON)
(SEE SECTION B-B) STA
9139.4
REINSTALL SAME RIVET P/N NAS9302BNS-5-02 REF

DETAIL A
STRUCTURES AND SYSTEMS ARE PARTIALLY
OMITTED FOR BETTER CLARITY PURPOSE

ONLY FOR LOCATION 2

REMOVE:
3G5350A18954 LOWER LEFT MACHINED (DOWN)
3G5350A19454 SHIM DOWN 3G5350A12851 LONGERON
3G5350A19754 STRIP DOWN (REF)
(RETAIN FOR LATER REUSE)

TOOLING DRILL AXIS

C

DRILL:
HOLE Ø3.25
ONLY ON LONGERON

SECTION CUT B-B SB139-616-006-01

Figure 2
S.B. N°139-616 RECOMMENDED
DATE: June 19, 2024
REVISION: / Page 21 of 35
 E 1

Page 22 of 35
2 INSTALL:
3G5350R00953
REINFORCEMENT ANGLE
APPLY:
EA9309.NA ADHESIVE
D

INSTALL:
3G5350R00951 SHIM ANGLE INSTALL:
APPLY: 3G5350A12851 LONGERON NAS9301BNS-6-04 RIVET (9 OFF)
EA9309.NA ADHESIVE (REF)
3G5350A12851 LONGERON
(REF) D 3G5350A12851 LONGERON
DRILL: (REF)
HOLE Ø10.0
ONLY ON THE LONGERON TO ELIMINATE
PREVIOUS SLOTTED HOLES
VIEW C
3G5350R00953 STRUCTURES AND SYSTEMS ARE PARTIALLY
REINFORCEMENT ANGLE OMITTED FOR BETTER CLARITY PURPOSE
(REF)

Figure 3
3G5350R00951 SHIM ANGLE
(REF)

NAS9301BNS-6-04 RIVET
(REF)

SECTION CUT D-D

3G5350R00953
REINFORCEMENT ANGLE

REMOVE EXISTING RIVET

INSTALL: REMOVE EXISTING RIVET
MS90353S0503 RIVET (5 OFF) INSTALL:
VIEW E NAS9302BNS-6-04 RIVET (4 OFF)
STRUCTURES AND SYSTEMS ARE PARTIALLY
OMITTED FOR BETTER CLARITY PURPOSE

SB139-616-007-03

S.B. N°139-616 RECOMMENDED

REVISION: /
DATE: June 19, 2024
 3G5350A00132 TAIL BOOM ASSY (REF)

REVISION: /
3G5350A00133 TAIL BOOM ASSY (REF)
3G5350A00134 TAIL BOOM ASSY (REF)
3G5350A00135 TAIL BOON ASSY (REF)

3G5350A12851 LONGERON
(REF)

DATE: June 19, 2024

J
INSTALL:
NAS9301BNS-6-04 RIVET (12 OFF)

S.B. N°139-616 RECOMMENDED

INSTALL:
NAS9301BNS-6-03 RIVET (12 OFF)

VIEW H
STRUCTURES AND SYSTEMS ARE PARTIALLY
OMITTED FOR BETTER CLARITY PURPOSE

INSTALL:

Figure 4
A297A06TW13 RIVET (4 OFF) K

INSTALL:
NAS9301BNS-6-05 RIVET (11 OFF)

3G5350A12851 LONGERON
REINSTALL: (REF)
3G5350A18954 LOWER LEFT MACHINED (DOWN)

REINSTALL:
3G5350A19454
K LOWER LAMINATED SHIM DOWN

3G5350A18954
LOWER LEFT MACHINED (DOWN)
(REF) REINSTALL:
3G5350A19754
LOWER LONGERON STRIP DOWN
DETAIL J

SECTION K-K

SB139-616-011-01

Page 23 of 35
 3G5350R00953
REINFORCEMENT ANGLE
MATERIAL AL-ALY 2024 T3
AMS-QQ-A-250/4, TH 2.00, N+XPFW/1

136.0

R 5.00 85.9
TYP
10.00

F
9 X Ø2.50 PILOT HOLES R 10.0

R 13.0 R 10.0
15.00

12.0
8˚
R 10.0

25.43 T
YP
12.00
F
50.86

182.00

FRONT VIEW

103˚
35.0
FINISH CODES:
N = Chromic acid anodising not sealed
R 6.50
XPFW = Waterborne chromate free primer
TYP

24.4

SECTION CUT F-F

SB139-616-008-02

Figure 5
S.B. N°139-616 RECOMMENDED
DATE: June 19, 2024
Page 24 of 35 REVISION: /
 3G5350R00951 SHIM ANGLE
MATERIAL AL-ALY 2024 T3
AMS-QQ-A-250/4, TH 1.02, N+XPFW/1

75.2

R 5.0 G
TYP

98.1˚

79.4

FRONT VIEW

1.0 REF

35.6 FINISH CODES:

104˚ N = Chromic acid anodising not sealed
XPFW = Waterborne chromate free primer

R 8.5

24.8

SECTION CUT G-G

SB139-616-009-01

Figure 6
S.B. N°139-616 RECOMMENDED
DATE: June 19, 2024
REVISION: / Page 25 of 35
 3G5350R00811
TAIL LOWER LH LONGERON
HF ANTENNA REPAIR

Page 26 of 35
3G5350A00136 TAIL BOOM ASSY
(REF)

WL
2751.6
WL REF
2667.6
REF

Figure 7
WL
2015.1
REF

WL
1848.6
REF
STA
WL 12299.2
1681.2 REF
REF
STA
WL STA 11358.7
1570.0 11020.0 REF
STA
REF 10249.1 REF
REF

STA STA HF ANTENNA INSTALLATION (REF)

8700.1 9139.4
REF REF

VIEW LOOKING INBOARD LEFT SIDE

SB139-616-001-01

S.B. N°139-616 RECOMMENDED

REVISION: /
DATE: June 19, 2024
 TAIL BOOM ASSY B
(REF)
B
3G5315A17252 DOUBLER
(REF)

3G5315A15951 (REF)

WL
1681.2
REF REMOVE EXISTING RIVET
DRILL:
HOLE Ø3.25 NORMAL TO
EXTERNAL PROFILE LAST
TO LONGERON
3G5316A46451 FW COVER LH
SEE SECTION B-B
(REF)
REINSTALL SAME
RIVET P/N AGS4720-508
1
B
REMOVE EXISTING RIVET
B 2

DRILL: STA
9139.4
HOLE Ø3.25 NORMAL TO REF
EXTERNAL PROFILE LAST TO LONGERON
(SEE SECTION B-B)
REINSTALL SAME RIVET P/N AGS4720-508

DETAIL A
STRUCTURES AND SYSTEMS ARE PARTIALLY
OMITTED FOR BETTER CLARITY PURPOSE

3G5350A20751 LEFT EXTERNAL SKIN

(REF)

3G5350A22551 LONGERON
(REF)

3G5315A17252 DOUBLER
(REF)

TOOLING DRILL AXIS

DRILL:
HOLE Ø 3.25

SECTION CUT B-B

SB139-616-002-01

Figure 8
S.B. N°139-616 RECOMMENDED
DATE: June 19, 2024
REVISION: / Page 27 of 35
 2 1
E

Page 28 of 35
D
INSTALL: 3G5350A22551 LONGERON
3G5350R00851 SHIM (REF)
APPLY:
EA9309.NA ADHESIVE

INSTALL:
A297A06TW03 RIVET (12 OFF)
D
3G5350A22551
3G5350A22551 LONGERON (REF)
DRILL:
LONGERON (REF) HOLE Ø10.0
INSTALL: ONLY ON THE LONGERON TO ELIMINATE PREVIOUS
3G5350R00852 REINFORCEMENT ANGLE SLOTTED HOLES
APPLY:
EA9309.NA ADHESIVE

Figure 9
VIEW C
STRUCTURES AND SYSTEMS ARE PARTIALLY
OMITTED FOR BETTER CLARITY PURPOSE

3G5350R00851 SHIM REMOVE EXISTING RIVET

INSTALL: REMOVE EXISTING RIVET
(REF) A299A06TW05 RIVET (6 OFF) INSTALL:
3G5350R00852 A299A06TW04 RIVET (3 OFF)
REINFORCEMENT ANGLE (REF)

SECTION CUT D-D

REMOVE EXISTING RIVET

INSTALL:
A299A06TW04 RIVET (4 OFF)

VIEW E
STRUCTURES AND SYSTEMS ARE PARTIALLY
OMITTED FOR BETTER CLARITY PURPOSE

SB139-616-003-01

S.B. N°139-616 RECOMMENDED

REVISION: /
DATE: June 19, 2024
 3G5350R00852
REINFORCEMENT ANGLE
MATERIAL AL-ALY 2024 T0
AMS-QQ-A-250/4, TH 2.00, N+XPFW/1
(FINAL HEAT TREATING T42)

317.4

12X Ø2.5 PILOT HOLES

12.0

296.8

R 5.0
TYP
27.0 TYP
F

10.0
172˚
172˚

F
320.7

FRONT VIEW

2.0 REF

110˚

32.6 FINISH CODES:

R 6.5 N = Chromic acid anodising not sealed
XPFW = Waterborne chromate free primer

24.4

SECTION CUT F-F

SB139-616-004-02

Figure 10
S.B. N°139-616 RECOMMENDED
DATE: June 19, 2024
REVISION: / Page 29 of 35
 3G5350R00851 SHIM ANGLE
MATERIAL AL-ALY 2024 T3
AMS-QQ-A-250/4, TH 0.40, N+XPFW/1

48.6

G
R 5.0
TYP

172˚

G
49.1

FRONT VIEW

0.4 REF

34.1
FINISH CODES:
110˚ N = Chromic acid anodising not sealed
XPFW = Waterborne chromate free primer

R 8.5

24.9

SECTION CUT G-G

SB139-616-010-01

Figure 11
S.B. N°139-616 RECOMMENDED
DATE: June 19, 2024
Page 30 of 35 REVISION: /
REVISION: /
3G5350R01011
TAIL LOWER LH LONGERON
HF ANTENNA REPAIR

DATE: June 19, 2024

3G5350A00132 TAIL BOOM ASSY (REF)
3G5350A00133 TAIL BOOM ASSY (REF)
STA 3G5350A00134 TAIL BOOM ASSY (REF)

S.B. N°139-616 RECOMMENDED

8701.60
REF

WL
2751.6
WL REF
2667.64
REF

Figure 12
STA
STA 12299.2
11358.7 REF
REF
WL
1570.01
REF
STA
10249.1 HF ANTENNA INSTALLATION
REF
A (REF)
STA
8700.1
REF

3G5309P01812 TAIL REINFORCEMENT RETRO MODIFICATION

(REF)

VIEW LOOKING INBOARD LEFT SIDE

SB139-616-012-01

Page 31 of 35
 3G5315A15951 FW COVER LH
(REF)

3G5350A20351 DOUBLER 3G5350A16153 LEFT LOWER DOUBLER EXTERNAL

(REF) (REF)

TAIL ASSY
(REF)
B
B

2
WL
1681.2
REF

B B REMOVE EXISTING RIVET

DRILL:
HOLE Ø3.25 NORMAL TO
REMOVE EXISTING RIVET EXTERNAL PROFILE (ONLY ON LONGERON)
DRILL: (SEE SECTION B-B)
HOLE Ø3.25 NORMAL TO REINSTALL SAME RIVET P/N NAS9302BNS-5-02
EXTERNAL PROFILE (ONLY ON LONGERON)
(SEE SECTION B-B) STA
9139.4
REINSTALL SAME RIVET P/N NAS9302BNS-5-02 REF

DETAIL A
STRUCTURES AND SYSTEMS ARE PARTIALLY
OMITTED FOR BETTER CLARITY PURPOSE

3G5350A12851 LONGERON
(REF)

TOOLING DRILL AXIS

C

DRILL:
HOLE Ø3.25
ONLY ON LONGERON

SECTION CUT B-B

SB139-616-013-01

Figure 13
S.B. N°139-616 RECOMMENDED
DATE: June 19, 2024
Page 32 of 35 REVISION: /
 E 1

REVISION: /
DATE: June 19, 2024
2
INSTALL:
3G5350R01052
REINFORCEMENT ANGLE
APPLY:
EA9309.NA ADHESIVE
D

S.B. N°139-616 RECOMMENDED

3G5350A12851 LONGERON INSTALL:
(REF) NAS9301BNS-6-04 (16 OFF)
INSTALL:
3G5350R01051 SHIM ANGLE
APPLY:
EA9309.NA ADHESIVE D
3G5350A12851 LONGERON
(REF) DRILL:
HOLE Ø10.0
ONLY ON THE LONGERON TO ELIMINATE
VIEW C PREVIOUS SLOTTED HOLES
STRUCTURES AND SYSTEMS ARE PARTIALLY
OMITTED FOR BETTER CLARITY PURPOSE

3G5350R01052

Figure 14
3G5350R01051 SHIM ANGLE
REINFORCEMENT ANGLE
(REF)
(REF)

NAS9301BNS-6-04 RIVET
(REF)

SECTION CUT D-D

3G5350R01052
REINFORCEMENT ANGLE

REMOVE EXISTING RIVET

INSTALL:
NAS9302B-6-04 RIVET (14 OFF)

VIEW E
STRUCTURES AND SYSTEMS ARE PARTIALLY
OMITTED FOR BETTER CLARITY PURPOSE

SB139-616-014-01

Page 33 of 35
 3G5350R01051
SHIM ANGLE
MATERIAL AL-ALY 2024 T3
AMS-QQ-A-250/4, TH 1.02, N+XPFW/1

182.3

R 5.0
TYP

98
.1
˚
A
186.5

FRONT VIEW
35.6

10
4˚

FINISH CODES:
R 8.5 N = Chromic acid anodising not sealed
XPFW = Waterborne chromate free primer

24.
8

SECTION A-A

SB139-616-015-01

Figure 15
S.B. N°139-616 RECOMMENDED
DATE: June 19, 2024
Page 34 of 35 REVISION: /
 3G5350R01052
REINFORCEMENT ANGLE
MATERIAL AL-ALY 2024 T3
AMS-QQ-A-250/4, TH 2.00, N+XPFW/1

241.0
190.9
R 5.00
TYP

10.00
16 X Ø2.50 PILOT HOLES A
15.00

R 10.0

R 13.0 R 10.0

12.0
8˚
R10.0
26.00
13.00
4x26.00=
(104.00) 25.43

4x25.43= A
(101.72)
50.86
287.00
35.0

10
3˚

FINISH CODES:
R 6.50 TYP N = Chromic acid anodising not sealed
XPFW = Waterborne chromate free primer

24.4

SECTION A-A

SB139-616-016-01

Figure 16
S.B. N°139-616 RECOMMENDED
DATE: June 19, 2024
REVISION: / Page 35 of 35
 Please send to the following address:
SERVICE BULLETIN COMPLIANCE FORM Date:

LEONARDO S.p.A.
CUSTOMER SUPPORT & SERVICES - ITALY Number:

PRODUCT SUPPORT ENGINEERING & LICENSES DEPT.

Via Giovanni Agusta, 520
21017 Cascina Costa di Samarate (VA) - ITALY Revision:
Tel.: +39 0331 225036 Fax: +39 0331 225988

Customer Name and Address: Telephone:

Fax:

B.T. Compliance Date:

Helicopter Model S/N Total Number Total Hours T.S.O.

Remarks:

Information:

We request your cooperation in filling this form, in order to keep out statistical data relevant to aircraft configuration up-to-date. The form should be filled in all
its parts and sent to the above address or you can communicate the application also via Technical Bulletin Application Communication Section placed in
Leonardo AW Customer Portal - MyCommunications Area. We thank you beforehand for the information given.