Via Giovanni Agusta, 520

21017 Cascina Costa di Samarate (VA) Italy

Tel.: +39 0331-229111 - Fax: +39 0331-229605/222595

An Company

TRANSLATION OF

BOLLETTINO TECNICO N° 139-004

The technical content of this document is approved
under the autority of DOA nr. EASA.21J.005 April
DATECosta
21017 Cascina 18, 2005
di Samarate (VA) Italy
Via Giovanni Agusta, 520
A FINMECCANICA COMPANY Tel.: +39 0331 229111 - Fax: +39 0331 229605 - 222595
REV. /

Compliance with
this bulletin is: MANDATORY

SUBJECT: UPPER DECK INSULATING COVERS P/N 3G5306P07511 INSTALLATION.

21017 Cascina Costa di Samarate (VA) Italy

S.p.A.
Via Giovanni Agusta, 520
Tel. (0331) 229111 - Tlx. 332569 - Fax: (0331) 229605
REASON: Provide the necessary instructions to permit the installation of the insulating
covers P/N 3G5306P07511, in order to prevent the possibility of upper deck
panels voids (bonding separation).

HELICOPTERS AFFECTED: on Agusta AB139 helicopters S/N 31006 and 31008.

COMPLIANCE: within the next 400 hours of flight.

Costruzioni Aeronautiche Giovanni AGUSTA - Cascina Costa (Gallarate) - Italia

DESCRIPTION: Voids (bonding separation) have been discovered, on some Agusta
AB139 helicopters in the upper panel P/N 3P5340A01131 and in the upper rear panel P/N
3P5333A01531 of upper deck area. The voids, due to the high temperatures of the
engines exaust nozzles, are located in the upper side of the above mentioned upper deck
panels. This Bollettino is issued to provide all the necessary procedures for the upper
panel P/N 3P5340A01131 and upper rear panel P/N 3P5333A01531 inspection, repair
and for the installation of the insulating covers P/N 3G5306P07511.
Failure to comply with this Bollettino can resulting severe additional structural damage to
the upper deck panels.

An appropriate entry should be made in the aircraft log book upon accomplishment.
I f o w n e r s h i p o f a i r c r a f t h a s c h a n g e d , p l e a s e , f o r w a r d t o n e w o w n e r.

Page 1 of 16
B.T. 139-004

REQUIRED MANPOWER: approximately 80 man-hours are required to accomplish this

bollettino. Man-hours are based on hands-on time and may vary with personnel and
facilities available.

WARRANTY: N.A.

REQUIRED MATERIALS: the following materials, necessary to accomplish this

bollettino, can be required to Agusta company:

P/N NOMENCLATURE Q.TY

3G0203R01111 Upper Deck Stringers Installation 1
Composed by:
3G0203R01151 LH STRINGER (*) 1
3G0203R01152 LH STRINGER (*) 1
3G0203R01153 RH STRINGER (*) 1
3G0203R01154 STRIP (*) 1
3G0203R01155 STRIP (*) 1
3G0203R01156 STRIP (*) 1
3G0203R01157 STRIP (*) 1
3G0203R01158 STRIP (*) 1
80-007-09-3 Insert .48
AN525-10R6 Screw .29
MS20470AD5-6 Rivet .3
MS20470AD5-7 Rivet .14

(*) Reworked according to 3G0203R01111 from:

A170A024C2 Metallic Extrusion 0,5 m
A166A013B2 Metallic Extrusion 3m
900004512 Metal Sheet 0.5 x 1 m

3G5306P07511 Upper Deck Insulating Covers Installation 1

Composed by:
3G5340A00231 Central insulating cover assy 1
3G5340A00331 Left insulating cover assy 1
3G5340A00431 Right insulating cover assy 1
3G5340A01031 Front insulating cover assy 1
NAS1832-3-3 Insert .63
AN525-10R6 Screw .63
AN525-10R9 Screw .19

Page 2 of 16
 B.T. 139-004

In addition, the following consumable materials are required (normally commercially

available but also available at Service Stations):
P/N NOMENCLATURE Q.TY
Adhesive, Epoxy, Ty. II Cl. 2
199-05-002 .AR
Cod. 900005009
Adhesive, Epoxy, Ty. II Cl. 2
199-05-002 .AR
Cod. 900004603
Adhesive, RBR, Ty. II
199-05-152 .AR
Cod. 900002979
Methylethilketone or 32002675
TT-M-261 .AR
Cod. 505407211

SPECIAL TOOLS: N.A.

WEIGHT AND BALANCE CHANGES: N.A.

REFERENCES:
1) AB139 Aircraft Maintenance Publication (AMP)
2) AB139 Structural Repair Publication (SRP)

PUBLICATIONS AFFECTED:
• AB139 Aircraft Maintenance Publication (AMP)
• AB139 Illustrated Parts Data (IPD)

COMPLIANCE INSTRUCTIONS:
Procedures to rework P/N’s A170A024C2, A166A013B2, P/N 900004512
a) Metallic Extrusion P/N 3G0203R01152 and 3G0203R01153
To obtain P/N 3G0203R01152 and 3G0203R01153, cut the Metallic Extrusion P/N
A166A013B2 to have two pieces of 1,436 m and 1,528 m long according to drawing
P/N 3G0203R01111 (Refer to Appendix A). Referring to figure 1, drill 22 equally
spaced holes of 5 mm Dia. onto the metallic extrusions 1,436 m long and 24 equally
spaced holes of 5 mm Dia. onto the 1,528 m.

Page 3 of 16
B.T. 139-004

b) Metallic Extrusion P/N 3G0203R01151 (Refer to Appendix A)

To obtain P/N 3G0203R01151, cut the Metallic Extrusion P/N A170A024C2 to have
one piece of 0,156 m long according to drawing P/N 3G0203R01111. Referring to
figure 1, drill 2 holes of 5 mm Dia. onto the metallic extrusions 0,156 m long.
c) Metallic Sheet P/N 3G0203R01154, 3G0203R01155, 3G0203R01156,
3G0203R01156, 3G0203R01158 (Refer to Appendix A)
Rework the Metallic Sheet P/N A170A024C2 to obtain five pieces of 0,005 m2,
0,028 m2, 0,031 m2, 0,024 m2, 0,042 m2 according to drawing P/N
3G0203R01111.
1. Prepare the helicopter for a safe ground maintenance. Disconnect the battery and all
the electrical power sources and/or the external power supply.
2. Gain access to the upper panel P/N 3P5340A01131 and in the upper rear panel P/N
3P5333A01531 of upper deck, removing from the helicopter the following
items/installation in accordance with the AB139 Aircraft Maintenance Publication
(AMP):
Ø Top forward cowling, left and right aft cowlings, top aft cowling.
Ø Engines exaust nozzles.
Ø Tail drive shaft and bearing support.
Ø High Pressure Tube and Temperature Control Valve.
Ø Rotor brake hose quick disconnect manifold.
Ø Wirings and all other parts necessary to free the upper deck work area.
3. In accordance with figure 4, remove from upper deck (STA 5891,0 BL 0,0 WL 267,0)
the barrier P/N 3G3070A07651 as follows:
a. In accordance with figure 4 view AS, drill out the seventeen P/N AGS4719-409
fixing rivets and remove the barrier P/N 3G3070A07651.
b. Remove any trace of sealant using a cloth dampened with Methylethilketone.
c. Deburr and protect the metal bared parts in accordance with the AB139 Structural
Repair Publication (SRP).
d. Close the seventeen rivet holes with adhesive EA934NA A+B, then shave the
surface.

Page 4 of 16
 B.T. 139-004

4. Remove all bonded wiring cables fixing brackets from the upper panel P/N
3P5340A01131 and in the upper rear panel P/N 3P5333A01531.
CAUTION
During the above mentioned operation, pay
particular attention to avoid honeycomb panel
damages.
5. Gain access to the upper panel P/N 3P5340A01131 and upper rear panel P/N
3P5333A01531 lower side through the helicopter empty compartment between STA
5795,0 and STA 6700,0, removing seats, panels and access doors necessary to free
the work area in accordance with the AB139 Aircraft Maintenance Publication (AMP).
6. Inspect the upper side of the upper panel P/N 3P5340A01131 and upper rear panel
P/N 3P5333A01531 for voids (bonding separation) by tapping with a suitable sounding
device.
In case voids are detected, perform four 1,78-2,36 mm Dia. holes through the panel
upper skin at the edges of the damaged area.

NOTE
If the damaged area is bigger than 35 cm2,
additional 1,78-2,36 mm Dia. holes are required.
7. In accordance with figure 1 and figure 2, rework the upper panel P/N 3P5340A01131
and upper rear panel P/N 3P5333A01531 as follows:
a. In accordance with figure 1 view A-A, remove from panels, the existing fixing rivets
which interfere with the installation of the RH STRINGER P/N 3G0203R01153, the
LH STRINGER P/N 3G0203R01151 and the LH STRINGER P/N 3G0203R01152.
b. In accordance with figure 1 view A-A, temporarily install the stringers P/N
3G0203R01151, P/N 3G0203R01152 and P/N 3G0203R01153 in their position on
panels P/N 3P5340A01131 and P/N 3P5333A01531. Countersign the stringers
existing pilot holes on panels and vice versa the panels existing fixing rivets holes
on stringers.
c. Rework P/N 3G5340A00231, P/N 3G5340A00331, P/N 3G5340A00431 and P/N
3G5340A01031 according to drawing 3G5306P07511.

Page 5 of 16
B.T. 139-004

d. In accordance with figure 2 view A-A, temporarily install the reworked insulating
covers P/N 3G5340A00231, P/N 3G5340A00331, P/N 3G5340A00431 and P/N
3G5340A01031 in their position on panels P/N 3P5340A01131 and P/N
3P5333A01531. Countersign the insulating covers fixing holes on panels.
e. Remove the insulating covers and the stringers from the panels P/N
3P5340A01131 and P/N 3P5333A01531.
f. Enlarge the existing pilot holes of stringers P/N 3G0203R01151, P/N
3G0203R01152 and P/N 3G0203R01153 to 5,00 mm Dia.
g. Enlarge the existing pilot holes of strips P/N 3G0203R01154, P/N 3G0203R01155,
P/N 3G0203R01156, P/N 3G0203R01157 and P/N 3G0203R01158 to 9,50-9,60
mm Dia.
h. Drill the countersigned rivets holes on stringers P/N 3G0203R01151, P/N
3G0203R01152 and P/N 3G0203R01153 to 4,09-4,22 mm Dia.
i. Deburr and protect the metal bared parts in accordance with the AB139 Structural
Repair Publication (SRP).
j. In accordance with figure 3, assemble the LH STRINGER P/N 3G0203R01151
and the LH STRINGER P/N 3G0203R01152 as follows:
Ø Position metallic extrusion P/N 3G0203R01151 and P/N 3G0203R01152 as
per figure 3, and drill three 4,09-4,22 mm Dia holes through the stringers.
Ø Deburr and protect the metal bared parts in accordance with the AB139
Structural Repair Publication (SRP).
Ø Assemble LH STRINGER P/N 3G0203R01151 and the metallic extrusion P/N
3G0203R01152 using three MS20470AD5-6 rivets.
k. In accordance with figure 1 section B-B, perform forty-eight 9,50-9,60 mm Dia
holes through upper panel P/N 3P5340A01131 and upper rear panel P/N
3P5333A01531, in the positions countersigned at step b.
l. In accordance with figure 2 section B-B and section C-C, perform sixty-five 14,25-
14,38 mm Dia holes with a depth of 10,00 mm through the upper skin and core of
the upper panel P/N 3P5340A01131 and upper rear panel P/N 3P5333A01531, in
the positions countersigned at step c.

Page 6 of 16
 B.T. 139-004

m. In each hole break the honeycomb core cells all around the circumference as
required, to provide a good housing for the adhesive. Remove all debris.

CAUTION
During the above mentioned operations, pay
particular attention to avoid honeycomb panel
damages. Moreover, during the drill phase, do not
overheat the panel skin in order to avoid
unbonding between core and skin.

n. In accordance with figure 1 section B-B, position the STRIPS P/N 3G0203R01154,
P/N 3G0203R01155, P/N 3G0203R01156, P/N 3G0203R01157 and P/N
3G0203R01158 and install the forty-eight inserts P/N 80-007-09-3 using adhesive
199-05-002 Type II Class 2. Allow adhesive to cure.
o. In accordance with figure 2 section B-B and section C-C, install the sixty-three
NAS1832-3-3 inserts using adhesive 199-05-002 Type II Class 2. Allow adhesive
to cure.
p. Before to install the stringers, if voids were detected in the upper panel P/N
3P5340A01131 and upper rear panel P/N 3P5333A01531 (ref. step 6.), repair the
damaged area as follows:
Ø Using a small tipped syringe inject a slow steady flow of adhesive 199-05-002
Type II Class 2 through one 1,78-2,36 mm Dia hole. Continue injecting until a
steady flow of adhesive is seen to emerge out of the opposite hole.
Ø Repeat for the others holes.
Ø To position the weights to do leave the air in excess from the panel.
Ø Clean excess of adhesive.
q. Install the stringers P/N 3G0203R01151, P/N 3G0203R01153 and P/N
3G0203R01154 in their position on panels P/N 3P5340A01131 and P/N
3P5333A01531 using twenty-nine AN525-10R6 screws and fourteen
MS20470AD5-7 rivets, as shown in figure 1 view A-A and section B-B.

CAUTION
Stringers must be installed immediately after the
injection of adhesive in panels voids. Do not wait
adhesive to cure. Clean excess of adhesive.

Page 7 of 16
B.T. 139-004

r. Rework P/N 3G5340A00231, P/N 3G5340A00331, P/N 3G5340A00431 and P/N

3G5340A01031 according to drawing 3G5306P07511.
s. Install the insulating covers P/N 3G5340A00231, P/N 3G5340A00331, P/N
3G5340A00431 and P/N 3G5340A01031 in their position on panels P/N
3P5340A01131 and P/N 3P5333A01531 using sixty-three AN525-10R6 screws
and nineteen AN525-10R9 screws.
t. Seal the insulating covers contours with 900002979 adhesive to avoid oils or fuels
infiltrations.
8. In accordance with the AB139 Aircraft Maintenance Publication (AMP) reinstall inside
the helicopter, seats, panels and access doors that have been removed.
9. In accordance with the AB139 Aircraft Maintenance Publication (AMP) reinstall on
helicopter upper deck, the following items/installation
Ø Top forward cowling, left and right aft cowlings, top aft cowling.
Ø Engines exaust nozzles.
Ø Tail drive shaft and bearing support.
Ø High Pressure Tube and Temperature Control Valve.
Ø Rotor brake hose quick disconnect manifold.
Ø Wirings and all others parts that have been removed.
10. Secure wiring cables clamps and/or brackets, as required, to the insulating covers
fixing screws.
11. Return helicopter to flight configuration and record for compliance of this Bollettino.

Page 8 of 16
 B.T. 139-004

Figure 1 (sheet 1 of 2)

Page 9 of 16
B.T. 139-004

Figure 1 (sheet 2 of 2)

Page 10 of 16
 B.T. 139-004

Figure 2 (sheet 2 of 2)

Page 11 of 16
B.T. 139-004

Figure 3

Page 12 of 16
 B.T. 139-004

Figure 4 (sheet 1 of 2)

Page 13 of 16
B.T. 139-004

Figure 4 (sheet 2 of 2)

Page 14 of 16
 B.T. 139-004

APPENDIX A

Page 15 of 16
B.T. 139-004

Page 16 of 16