# Leonardo Alert Service Bulletin 109S-115: No revision named

- Rights: © Leonardo S.p.A. Filed by the FAA in regulations.gov docket FAA-2023-2238, the docket of AD 2024-15-11. Not covered by OpenAirDocs’ CC0 dedication.
- Document: [Leonardo Alert Service Bulletin 109S-115](https://openairdocs.org/service-documents/leonardo/109s-115.md)
- Title as filed: Leonardo Helicopters ASB 109S-115
- Pages: 22
- PDF: https://openairdocs.org/files/sha256/3c/db/3cdb336bb8bb25ed2fa1d9b1ae173038b4fea9326943ade7168d162f3aa16eca
- Page: https://openairdocs.org/service-documents/leonardo/109s-115/file/3cdb336bb8bb

## Text

Some pages are OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N.

### Page 1

P age 1 of 21 
N ° 109S-115 
D ATE:  March 21, 2023 
REV. :  /  - March 15, 2017 
TITLE 
ATA 64 – TAIL ROTOR HOUSING AND SLIDER GROUP DISASSEMBLY AND 
REASSEMBLY 
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.
Leonardo S.p.A.
Via Giovanni Agusta, 520
21017 Cascina Costa di Samarate (VA) Italy
Tel.: +39 0331 229111 - Fax: +39 0331 229605/222595
ALERT
SERVICE BULLETIN

### Page 2

S.B. N°109S-115 ALERT 
 DATE: March 21, 2023 
Page 2 of 21 REVISION: / 
1. PLANNING INFORMATION 
A. EFFECTIVITY 
Part I: 
 All A109S helicopters (from S/N 22001 thru S/N 22199) that have performed 
maintenance activities requiring the disassembly of the tail rotor duplex bearing 
housing after the helicopter delivery. 
 All A109S helicopter with Trekker kit (from S/N 22701 thru S/N 22999) that have 
performed maintenance activities requiring the disassembly of the tail rotor duplex 
bearing housing after the helicopter delivery. 
Part II: 
 All A109S helicopters. 
 All A109S helicopters with Trekker kit. 
B. COMPLIANCE 
Part I: 
Within and not later than 100 (one hundred) flight hours or 6 (six) months, whichever 
occurs first, after the issue of this Service Bulletin. 
Part II: 
At each assembly of the tail rotor duplex bearing housing. 
C. CONCURRENT REQUIREMENTS 
N.A. 
D. REASON 
This Service Bulletin is issued in order to prescribe the disassembly and reassembly of 
the housing and slider group of the tail rotor rotating controls. 
E. DESCRIPTION 
There have been reported cases of ring-nut tighten loss, likely as a result of poor 
maintenance tasks accomplishment of the assembly instructions for the tail rotor 
housing and slider group. 
In order to minimize the likelihood of occurrence of potential human errors during 
maintenance, LH updated the maintenance instructions in order to provide additional 
guidelines, including a better identification Vital Points (VP) for the assembly of the tail 
rotor duplex bearing support.

### Page 3

S.B. N°109S-115 ALERT 
DATE: March 21, 2023 
REVISION: / Page 3 of 21 
As such, this Service Bulletin requires (Part I) to perform the installation of the tail rotor 
duplex bearing housing following the IETP updated instructions and (Part II) requires to 
follow such updated instructions whenever the TR duplex bearing housing is assembled. 
During the procedure, the operator must obey the Local Regulations applicable to the 
Vital Points. 
F. APPROVAL 
The technical content of this Service Bulletin is approved under the authority of DOA nr. 
EASA.21.J.005. 
EASA states mandatory compliance with inspections, modifications or technical directives 
and related time of compliance by means of relevant Airworthiness Directives. 
G. MANPOWER 
To comply with this Service Bulletin, the following MMH are deemed necessary: 
Part I: 8 (eight). 
Part II: N.A. 
MMH are based on hands-on time and can change with personnel and facilities available. 
H. WEIGHT AND BALANCE 
N.A. 
I. REFERENCES 
1) PUBLICATIONS 
DATA MODULE DESCRIPTION PART 
DM01 0B-A-00-20-00-00A-120A-A Helicopter safety - Pre-operation I 
DM02 0B-A-64-00-00-00A-520A-A Tail rotor – remove procedure I 
DM03 0B-A-64-31-06-00A-520A-A Housing and slider group –  
remove procedure 
I 
DM04 0B-A-64-31-06-00A-530A-B Housing and slider group –  
disassemble procedure 
I 
DM05 0B-A-64-31-06-00A-710A-B Housing and slider group –  
assemble procedure 
I, II 
DM06 0B-A-64-31-06-00A-720A-A Housing and slider group – install 
procedure 
I 
DM07 0B-A-64-00-00-00A-720A-A Tail rotor – install procedure I 
2) ACRONYMS & ABBREVIATIONS 
AMDI Aircraft Material Data Information 
AMP Aircraft Maintenance Publication

### Page 4

S.B. N°109S-115 ALERT 
 DATE: March 21, 2023 
Page 4 of 21 REVISION: / 
AMPI Aircraft Maintenance Planning Information 
DM Data Module 
DOA Design Organization Approval 
EASA European Aviation Safety Agency 
IETP Interactive Electronic Technical Publications 
IPD Illustrated Part Data 
ITEP Illustrated Tool and Equipment Publication 
LH Leonardo Helicopters 
MMH Maintenance Man Hours 
P/N Part Number 
S/N Serial Number 
3) ANNEX 
Annex A AMP DM 0B-A-64-31-06-00A-710A-B Issue 13 
J. PUBLICATIONS AFFECTED 
N.A. 
K. SOFTWARE ACCOMPLISHMENT SUMMARY 
N.A.

### Page 5

S.B. N°109S-115 ALERT 
DATE: March 21, 2023 
REVISION: / Page 5 of 21 
2. MATERIAL INFORMATION 
A. REQUIRED MATERIALS 
1) PARTS 
N.A. 
2) CONSUMABLES 
Refer also to AMDI for the consumable materials required to comply with the AMP 
DM referenced in the accomplishment instructions. 
3) LOGISTIC MATRIX 
N.A. 
B. SPECIAL TOOLS 
Refer also to ITEP for the special tools required to comply with the AMP DM referenced 
in the accomplishment instructions. 
C. INDUSTRY SUPPORT INFORMATION 
N.A.

### Page 6

S.B. N°109S-115 ALERT 
 DATE: March 21, 2023 
Page 6 of 21 REVISION: / 
3. ACCOMPLISHMENT INSTRUCTIONS 
GENERAL NOTES 
a) Place an identification tag on all components that 
are re-usable, including the attaching hardware that 
have been removed to gain access to the 
modification area and adequately protect them until 
their later re-use. 
b) Shape the cables in order to prevent interference 
with the structure and the other existing installations, 
using where necessary suitable lacing cords and 
plastic cable tiedown. 
PART I 
1. In accordance with AMP DM 0B-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. 
2. In accordance with AMP DM 0B-A-64-00-00-00A-520A-A, remove from the helicopter the 
tail rotor. 
3. In accordance with AMP DM 0B-A-64-31-06-00A-520A-A, remove the tail rotor housing 
and slider group. 
4. In accordance with AMP DM 0B-A-64-31-06-00A-530A-B, disassemble the tail rotor 
housing and slider group. 
NOTE 
Vital Point (VP): the point of a component, assembly or 
installation, where incorrect assembly or an undetected 
error could cause the loss of rotorcraft and/or fatalities. 
5. In accordance with AMP DM 0B-A-64-31-06-00A-710A- B Issue 13 (Ref. Leonardo 
WebPortal or Annex A of this Service Bulletin), assemble the tail rotor housing and slider 
group.  
6. In accordance with AMP DM 0B-A-64-31-06-00A-720A-A, install the tail rotor housing and 
slider group. 
7. In accordance with AMP DM 0B-A-64-00-00-00A-720A-A, install on the helicopter the tail 
rotor. 
8. Return the helicopter to a ready to flight condition and record for compliance with Part I of 
this Service Bulletin on the helicopter logbook.

### Page 7

S.B. N°109S-115 ALERT 
DATE: March 21, 2023 
REVISION: / Page 7 of 21 
9. Send the attached compliance form to the following mail box: 
 engineering.support.lhd@leonardo.com 
As an alternative, gain access to My Communications section on Leonardo WebPortal and 
compile the “Service Bulletin Application Communication”.

### Page 8

S.B. N°109S-115 ALERT 
 DATE: March 21, 2023 
Page 8 of 21 REVISION: / 
PART II 
NOTE 
Vital Point (VP): the point of a component, assembly or 
installation, where incorrect assembly or an undetected 
error could cause the loss of rotorcraft and/or fatalities. 
1. During the application of any maintenance operati on requiring the assembly of the TR 
duplex bearing housing, it is required to perform the relevant assembly procedure in 
accordance with AMP DM 0B-A-64-31-06-00A-710A-B Issue 13 (Ref. Leonardo 
WebPortal or Annex A of this Service Bulletin) or later published issues. 
2. Record for compliance with Part II of this Service Bulletin on the helicopter logbook. 
3. Send the attached compliance form to the following mail box: 
 engineering.support.lhd@leonardo.com 
As an alternative, gain access to My Communications section on Leonardo WebPortal and 
compile the “Service Bulletin Application Communication”.

### Page 9

ANNEX A 
S.B. N°109S-115 ALERT 
DATE: March 21, 2023 
REVISION: / Page 9 of 21 
 
 
 
ANNEX A 
AMP DM 0B-A-64-31-06-00A-710A-B ISSUE 13

### Page 10 (OCR)

ANNEX A  K LEONARDO  HELICOPTERS
A109S/AW109SP IETP 31st Issue  Unmaintained Copy  Page 1 of 12
Housing and slider group - Assemble procedure
Table of contents
References
Preliminary requirements
Procedure
Requirements after job completion
List of tables
References
Required conditions
Support equipment
4  Supplies
5  Spares
List of figures
Housing and slider group - Assemble procedure (Sheet 1 of 5)
Housing and slider group - Assemble procedure (Sheet 2 of 5)
Housing and slider group - Assemble procedure (Sheet 3 of 5)
Housing and slider group - Assemble procedure (Sheet 4 of 5)
Housing and slider group - Assemble procedure (Sheet 5 of 5)
References
Table 1 References
Data module  Title
09-A-00-50-00-00A-013A-D  Material data information publication -
Numeric index
OB-A-00-20-00-00A-120A-A  Helicopter safety - Pre-operation
OB-A-00-60-00-00A-010A-A  Critical parts - General data
OB-A-20-00-02-00A-712A-A  Fasteners, caps, electrical connectors and
turnbuckles - Lock procedure
OB-A-64-00-00-01A-311A-B  Tail rotor components - Visual check
OB-A-64-31-06-00A-720A-A  Housing and slider group - Install procedure
OB-A-64-31-06-00B-710A-B  Housing and slider group - Assemble
procedure
OB-A-GF-58-00-00A-066A-A  Tool set, TR pitch change slider ring nut
removal/installation (GF-58-00) - Support
equipment and tools data
OB-A-GF-59-00-00A-066A-A  Tool set, TR pitch change housing ring nut
removal/installation (GF-59-00) - Support
equipment and tools data
OB-A-GF-62-00-00A-066A-A
AMP - OB-A-64-31-06-00A-710A-B Housing and slider group - Assemble procedure Printed on 13/03/2023
S.B. N°109S-115 ALERT
DATE: March 21, 2023
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ANNEX A  * LEONARDO
A109S/AW109SP IETP 31 st Issue  Unmaintained Copy  Page 2 of 12
Data module  Title
Tool set, TR duplex bearing installation (GF-
62-00) - Support equipment and tools data
OB-A-GF-64-00-00A-066A-A  Tool set, TR pitch change slider installation
(GF-64-00) - Support equipment and tools
data
Preliminary requirements
Required conditions
Table 2 Required conditions
Required condition  Data module
The helicopter must be safe for maintenance  OB-A-00-20-00-00A-120A-A
Support equipment
Table 3 Support equipment
Nomenclature  Identification No.  Qty
Syringe  Local supply  1 EA
Pin  GF-62-01  1 EA
Base  GF-62-02  1 EA
Heating gun  Local supply  1 EA
Tool set, TR pitch change housing ring  GF-59-00  1 EA
nut removal/installation
Wrench  GF-59-01  1 EA
Bolt  GF-59-02  2 EA
Base  GF-59-01-01  • 1 EA
Tool set, TR pitch change slider  GF-64-00  1 EA
installation
Barrel  GF-64-01  1 EA
Bushing  GF-64-02  1 EA
Pin  GF-64-03  1 EA
Tool set, TR pitch change slider ring nut  GF-58-00  • 1 EA
removal/installation
Wrench  GF-58-01  1 EA
Base  GF-58-02  1 EA
Feeler gage  Local supply  1 EA
Depth micrometer gage  Local supply  1 EA
AMP - OB-A-64-31-06-00A-710A-B Housing and slider group - Assemble procedure Printed on 13/03/2023
S.B. N°109S-115 ALERT
DATE: March 21, 2023
REVISION: /  Page 11 of 21

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ANNEX A  * LEONARDO  HELICOPTERS
A109S/AW109SP IETP 31st Issue  Unmaintained Copy  Page 3 of 12
Nomenclature  Identification No.  Qty
Refrigerator  Local supply  1 EA
Supplies
Table 4 Supplies
Nomenclature  Identification No.  Qty
Grease  C594  AR
Primer  C446  AR
Cloth, soft lint-free  C011  AR
Solvent, cleaning  C023  AR
Adhesive  C029  AR
Wire, safety  C014  AR
Oil  C139  AR
Prim er  C237  AR
Spares
Table 5 Spares
Nomenclature  Identification No.  Qty
Lock ring  64310001-022  1 EA
Lock ring  64310001H-022  1 EA
Safety conditions
WARNINGS
• The materials that follow are dangerous. Before you do this procedure, make sure
that you know all the safety precautions and first aid instructions for these materials:
Grease (C594);
Primer (C446);
- Solvent, cleaning (C023);  Primer (C237);
- Adhesive (C029);
- Oil (C139).
• This installation includes Vital Points (VP). During the procedure, you must obey the
Local Regulations applicable to the Vital Points.
CAUTIONS
• Make sure that you do not mix greases of different brands although the specifications
are the same. Refer to the helicopter log book to prevent mixture of unwanted
greases.
AMP - OB-A-64-31-06-00A-710A-B Housing and slider group - Assemble procedure Printed on 13/03/2023
S.B. N°109S-115 ALERT
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ANNEX A  K LEONARDO  HELICOPTERS
A109S/AW109SP IETP 31st Issue  Unmaintained Copy  Page 4 of 12
• This component includes critical parts. Examine the component for signs of
structural damage, before you install it on the helicopter. Refer to:
OB-A-00-60-00-00A-010A-A.
Procedure
CAUTION
Before you assemble the housing and slider group (1, Fig 1) examine the components that
follow:
- The duplex bearing (4)
The housing (5).
Refer to OB-A-64-00-00-01A-311A-B.
Note 1
The procedure that follows is valid for the assembly of the housing and slider group with the
housing P/N 109-0130-94 and the locking nut P/N 109-0130-97.
Note 2
Refer to OB-A-64-31-06-00B-710A-B for the assembly of the housing and slider group with
the bearing support sleeve P/N 109G6430A03-101 and the flange P/N 109G6430A04-101.
Divide the two parts of the duplex bearing (4).
Note
Do Step 2 thru Step 4 only for removed bearings. New bearings are supplied already
lubricated and must not be filled with grease.
2  Fill the Syringe (Local supply) with the Grease (C594).
Before you install the bearing (8), fill it with 3.5 cc (0.21 in3) of grease with the syringe from the
side opposite to the boot. Refer to Detail A of Fig 1.
Do Step 3 again on the bearing (9).
5  Put the bearing (8) against the bearing (9) with the boot sides externally and the internal and
external V-marks aligned to show an arrow. See Detail A, Fig 1.
Install the duplex bearing (4) into the housing (5) in the way that follows:
6.1  Apply a thin layer of Primer (C446) on the mating surfaces between the duplex bearing (4) and
housing (5).
6.2  Put the housing (5) on the Base (GF-62-02) (10).
WARNING
Be careful when you use heat. Hot parts can cause injury to the persons. Always use
applicable protective clothing.
6.3  Heat the housing (5) to a temperature between 60 and 70 °C with the Heating gun (Local
supply). This will help you to install the duplex bearing (4) into the housing. Make sure that the
temperature is not more than 90 °C (heating gun set to a temperature of 90 °C).
Note
AMP - 0B-A-64-31-06-00A-710A-B Housing and slider group - Assemble procedure Printed on 13/03/2023
S.B. N°109S-115 ALERT
DATE: March 21, 2023
REVISION: /  Page 13 of 21

### Page 14 (OCR)

K LEONARDO
ANNEX A  HELICOPTERS
A109S/AW109SP IETP 31st Issue  Unmaintained Copy  Page 5 of 12
As an alternative to heating the housing (5); you can cool down the duplex bearing (4) with
the Refrigerator (Local supply) to a temperature between -18 and -40 °C for 30 minutes. Do
not touch the cold duplex bearing with bare hands to prevent injury.
6.4  Push the duplex bearing (4) into the housing (5). To do this, use the Pin (GF-62-01) (11) and an
applicable arbor press.
6.5  Make sure there is no clearance between the two bearings (8 and 9) and between the outer ring
of duplex bearing (4) and the shoulder of the housing (5). To do this, use the applicable Feeler
gage (Local supply).
6.6  Remove the housing-bearing assembly (12) from the base (10).
Note
Before you continue, make sure that all the components are at ambient temperature.
7  Install the ring nut (3) into the housing-bearing assembly (12). Obey the instructions that follow:
7.1  Clean the threads of the ring nut (3) and the housing (5) with the Cloth, soft lint-free (C011) and
the Solvent, cleaning (C023). (VP)
7.2  Dry the threads of the ring nut (3) and the housing (5) with a clean Cloth, soft lint-free (C011).
(VP)
7.3  Apply a layer of Primer (C237) on the threads of the ring nut (3).
7.4  Apply a layer of Primer (C237) on the threads of the housing (5).
7.5  Apply four drops of Adhesive (C029) on the threads of the ring nut (3). Put them in four equally
spaced positions (90 degrees apart). (VP
7.6  Lock the Base (GF-59-01-01) (14) in an applicable vice.
7.7  Put the housing-bearing assembly (12) on the base (14), then lock it with the two Bolt (GF-59-02)
(13).
7.8  Install the ring nut (3) in the housing-bearing assembly (12) with the Wrench (GF-59-01) (15).
7.9  Torque the ring nut (3) to 118 thru 127 N m (87 thru 94 Ibf ft). (VP)
7.10  Make sure that the duplex bearing (4) turns freely. (VP)
7.11  Refer to Detail B of Fig 1:
7.11.1  Measure and record the dimension L.
7.11.2  Make sure that the dimension you find is between 23.75 to 24.0 mm (0.935 to 0.945 in).
7.11.3  If you find that the dimension is not in the given limits, remove the duplex bearing (4). Then, do
Step 6 and Step 7 again.
7.12  Refer to Detail C of Fig 1:
7.12.1  Measure and record the dimension M.
7.12.2  Calculate and record the dimension N with this formula: N = M - L.
7.13  Remove the housing group (16) from the base (14).
Note
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DATE: March 21, 2023
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• LEONARDO
ANNEX A  HELICOPTERS
A109S/AW109SP IETP 31st Issue  Unmaintained Copy  Page 6 of 12
The safety wire must be installed with the double-twist method and put in tension. Example
of an acceptable safety wire installation is shown in Detail B1 of Fig 1. As a general
approach, an "a" angle between 60° and 120° is adviseable.
7.14  Safety the ring nut (3) to the housing (5) with the new Wire, safety (C014) in two places as
shown in Detail B1 of Fig 1. Refer also to OB-A-20-00-02-00A-712A-A. (VP)
Apply a thin layer of Oil (C139) on the internal surface of the duplex bearing (4).
9  Put the Bushing (GF-64-02) (18) in its position on the Pin (GF-64-03) (19).
10  Put the housing group (16) on the pin (19) above the bushing (18).
11  Put the slider (2) on the pin (19).
Note
To help you install the slider (2), heat the housing group (16) in an oven preheated to a
temperature of 50 °C for 15 to 30 minutes.
As an alternative to heating the housing group (16); you can cool down the slider (2) with the
Refrigerator (Local supply) to a temperature between -18 and -40 °C for 30 minutes. Do not
touch the cold slider with bare hands to prevent injury.
12  Push the slider (2) into the housing group (16). To do this, use the Barrel (GF-64-01) (17) and an
applicable arbor.
13  Remove the housing-slider assembly (20) from the pin (19).
Note
Before you continue, make sure that all the components are at ambient temperature.
14  Make sure there is no clearance between the inner rings of the two bearings (8 and 9) and the
shoulder of the slider (2). To do this, use the applicable Feeler gage (Local supply).
15  Refer to Detail D of Fig 1:
15.1  Measure and record the dimension N. To do this, use an applicable Depth micrometer gage
(Local supply).
15.2  Make sure that the dimension N measured agrees with the dimension calculated at Step 7.12.2
15.3  If you find that the dimension N does not agree, remove the duplex bearing (4). Then, do Step 6
and Step 15 again.
16  Lock the Base (GF-58-02) (22) in an applicable vice
17  Put the housing-slider assembly (20) on the base (22).
18  Move the braces (23) of the slider against the pins (24) of the base (22). Refer to Detail E of Fig
19  Clean the threads of the ring nut (6) and the slider (2) with the Cloth, soft lint-free (C011) and the
Solvent, cleaning (C023). (VP)
20  Dry the threads of the ring nut (6) with a clean Cloth, soft lint-free (C011). (VP)
21  Apply a layer of Primer (C237) on the threads of the ring nut (6).
22  Apply a layer of Primer (C237) on the threads of the slider (2).
AMP - 0B-A-64-31-06-00A-710A-B Housing and slider group - Assemble procedure Printed on 13/03/2023
S.B. N°109S-115 ALERT
DATE: March 21, 2023
REVISION: /  Page 15 of 21

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: LEONARDO
ANNEX A  HELICOPTERS
A109S/AW109SP IETP 31st Issue  Unmaintained Copy  Page 7 of 12
23  Apply four drops of Adhesive (C029) on the threads of the ring nut (6). Put them in four equally
spaced positions (90 degrees apart). (VP)
24  Install the ring nut (6) with the Wrench (GF-58-01) (21).
25  Torque the ring nut (6) to 49 thru 59 N m (36 thru 43 Ibf ft). (VP)
26  Remove the housing and slider group (1) from the base (22).
27  Install the new Lock ring (64310001-022) or Lock ring (64310001H-022) (7).
28  Bend the clawed tabs of the lock ring (7) on the ring nut (6). Make sure that the two clawed tabs
of the lock ring (7) are correctly engaged.
Requirements after job completion
Install the housing and slider group. Refer to OB-A-64-31-06-00A-720A-A.
AMP - OB-A-64-31-06-00A-710A-B Housing and slider group - Assemble procedure Printed on 13/03/2023
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K LEONARDO
ANNEX A  HELICOPTERS
А109S/AW109SP IETP 31st Issue  Unmaintained Copy  Page 8 of 12
EXTERNAL
V-MARK (REF)
INTERNAL  BOOT SIDE
V-MARK (REF)
(REF)  2
INTERNAL
V-MARK (REF)
BOOT SIDE 9 INTERNAL  SIDE
(REF)
ICN-OB-A-643106-G-00001-03005-A-004-01
Figure 1 Housing and slider group - Assemble procedure (Sheet 1 of 5)
AMP - OB-A-64-31-06-00A-710A-B Housing and slider group - Assemble procedure Printed on 13/03/2023
S.B. N°109S-115 ALERT
DATE: March 21, 2023
REVISION: /  Page 17 of 21

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ANNEX A  * LEONARDO  HELICOPTERS
А109S/AW109SP IETP 31st Issue  Unmaintained Copy  Page 9 of 12
ICN-OB-A-643106-G-00001-02275-A-003-01
Figure 1 Housing and slider group - Assemble procedure (Sheet 2 of 5)
AMP - OB-A-64-31-06-00A-710A-B Housing and slider group - Assemble procedure Printed on 13/03/2023
S.B. N°109S-115 ALERT
DATE: March 21, 2023
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ANNEX A  ý LEONARDO  HELICOPTERS
А109S/AW109SP IETP 31st Issue  Unmaintained Copy  Page 10 of 12
13
15
B1
- HOUSING-BEARING
SAFETY WIRE  ASSY
- SAFETY WIRE
RING NUT
SAFETY WIRING SCHEME OF RING NUT
ICN-OB-A-643106-G-00001-02276-A-005-01
Figure 1 Housing and slider group - Assemble procedure (Sheet 3 of 5)
AMP - OB-A-64-31-06-00A-710A-B Housing and slider group - Assemble procedure Printed on 13/03/2023
S.B. N°109S-115 ALERT
DATE: March 21, 2023
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ANNEX A  K LEONARDO  HELICOPTERS
А109S/AW109SP IETP 31st Issue  Unmaintained Copy  Page 11 of 12
20
16 -
ICN-OB-A-643106-G-00001-02277-A-005-01
Figure 1 Housing and slider group - Assemble procedure (Sheet 4 of 5)
AMP - OB-A-64-31-06-00A-710A-B Housing and slider group - Assemble procedure Printed on 13/03/2023
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ANNEX A  * LEONARDO  HELICOPTERS
А109S/AW109SP IETP 31st Issue  Unmaintained Copy  Page 12 of 12
20
24
22
ROTATION SENSE
24
ICN-OB-A-643106-G-00001-02278-A-005-01
Figure 1 Housing and slider group - Assemble procedure (Sheet 5 of 5)
AMP - OB-A-64-31-06-00A-710A-B Housing and slider group - Assemble procedure Printed on 13/03/2023
S.B. N°109S-115 ALERT
DATE: March 21, 2023
REVISION: /  Page 21 of 21

### Page 22

Remarks:
Information: 
SERVICE BULLETIN COMPLIANCE   FORM Date:
Number:
Revision:
Please send to the following address: 
Telephone:
Fax:
 B.T. Compliance Date:
 Customer Name and Address:
 Helicopter Model S/N Total Number Total Hours T.S.O.
LEONARDO S.p.A.
CUSTOMER SUPPORT & SERVICES - ITALY
PRODUCT SUPPORT ENGINEERING & LICENSES DEPT. 
Via  Giovanni Agusta, 520
21017  Cascina  Costa di Samarate (VA) - ITALY 
Tel.: +39 0331 225036  Fax: +39 0331 225988
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.

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