# Leonardo Alert Service Bulletin 109K-074: No revision named

- Rights: © Leonardo S.p.A. Filed by the FAA in regulations.gov docket FAA-2021-0686, the docket of AD 2021-17-18. Not covered by OpenAirDocs’ CC0 dedication.
- Document: [Leonardo Alert Service Bulletin 109K-074](https://openairdocs.org/service-documents/leonardo/109k-074.md)
- Title as filed: Leonardo Helicopters ASB No. 109K-074
- Pages: 34
- PDF: https://openairdocs.org/files/sha256/2a/b3/2ab37ca75d99a4a838a1e58e45e0a1d564fed2ac819ae2844d9227c1ab1f1565
- Page: https://openairdocs.org/service-documents/leonardo/109k-074/file/2ab37ca75d99

## Text

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### Page 1

N° 109K-074 
DATE:  April 26, 2021 
REV. :  / - March 15, 2017 
Page 1 of 33 
TITLE 
ATA 64 - INSPECTION OF TAIL ROTOR SHAFT ASSY P/N 109-0445-08-(ALL DASHES) 
AND TAIL ROTOR SLEEVE ASSY P/N 109-0130-90-117/-121 
REVISION LOG 
New 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°109K-074 ALERT 
 DATE: April 26, 2021 
Page 2 of 33 REVISION: / 
1. PLANNING INFORMATION 
A. EFFECTIVITY 
All the Leonardo S.p.a. A109K2 helicopters installing a TR sleeve assy P/N 109-0130-
90-117 all S/Ns, or P/N 109-0130-90-121 with S/Ns MO .001 to S/N MO.677 and with 
S/N MOR678 to MOR1140. 
B. COMPLIANCE 
NOTE 
TR sleeve assy P/N 109-0130-90-117/-121 marked with 
letter “R” after S/N are not affected by Part II and  Part 
III. 
Part I: 
Within and not later than 25 flight hours or 3 mont hs whichever occurs first after the 
issue of this Service Bulletin. 
Part II: 
Every 25 flight hours after accomplishment of part I and until application of Part III of this 
Service Bulletin or until installation of a non affected sleeve. 
Part III: 
At any bushing replacement. 
Part IV: 
In conjunction with every 400 FH scheduled inspection after application of Part I of this 
Service Bulletin until next TGB overhaul or TGB special inspection (1200 FH). 
C. CONCURRENT REQUIREMENTS 
N.A. 
D. REASON 
This Service Bulletin is issued in order to provide the  necessary instruction on how to 
perform a detailed inspection of tail rotor shaft assy P/N 109-0445-08-(all dashes) and 
tail rotor sleeve assy P/N 109-0130-90-117/-121. 
E. DESCRIPTION 
During tail rotor system inspections required after an a bnormal vibration event, an 
extensive crack has been found on the tail rotor mast of  an A109E helicopter at the 
interface with the tail rotor sleeve. In order to assu re the airworthiness of the fleet and 
to collect data for the investigation, LH decided to issue this SB to perform (Part I) a tail

### Page 3

S.B. N°109K-074 ALERT 
DATE: April 26, 2021 
REVISION: / Page 3 of 33 
rotor and mast visual inspection together with a dye p enetrant fluorescent liquid 
inspection in the area potentially affected by the issue and (Part II) a recurrent check for 
condition of the TR sleeve bushing. In case of sleeve bush ing debonding is found, 
instructions are given to replace it (Part III). Part IV provides instruction to restore, if 
necessary, solid lubricant protection on the area inspec ted with dye penetrant 
fluorescent liquid. 
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 Aut hority approval must be checked 
within Leonardo Helicopters customer portal. 
EASA states mandatory compliance with inspections, modifi cations or technical 
directives and related time of compliance by means of relevant Airworthiness Directives. 
If an aircraft listed in the effectivity embodies a m odification 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 incor poration of the present Service 
Bulletin. 
G. MANPOWER 
To comply with this Service Bulletin, the following MMH are deemed necessary: 
Part I: 5 (five) MMH; 
Part II: 0,5 (half an hour) MMH; 
Part III: 4 (four) MMH (without considering the adhesive curing time); 
Part IV: 0,25 (a quarter of hour) MMH. 
MMH are based on hands-on time and can change with per sonnel and facilities 
available. 
H. WEIGHT AND BALANCE 
N.A. 
I. REFERENCES 
1) PUBLICATIONS 
SECTION/PARAGRAPH DESCRIPTION PART 
PAR01 00-20-1 Helicopter Safety I, II, III

### Page 4

S.B. N°109K-074 ALERT 
 DATE: April 26, 2021 
Page 4 of 33 REVISION: / 
SECTION/PARAGRAPH DESCRIPTION PART 
PAR02 64-00-15 or 64-00-17 (from 
S/N 10001 thru 10015 and 
10027) 
Tail Rotor Hub and Blade 
Assembly, Removal/Installation 
I, II, III 
PAR03 64A-00-16 or 64A-00-18 (from 
S/N 10001 thru 10015 and 
10027) 
Tail Rotor Hub and Blade 
Assembly, Removal/Installation 
I, II, III 
PAR04 64-30-5 or 64-31-6 (from S/N 
10001 thru 10015 and 10027) 
Pitch Change Mechanism, 
Removal/Installation 
I, II, III 
PAR05 64-30-7 or 64-31-8 (from S/N 
10001 thru 10015 and 10027) 
Pitch Change Mechanism, 
Inspection 
I, II 
PAR06 65-20-5 or 65-21-6 (from S/N 
10001 thru 10015 and 10027) 
90-Degree Gearbox, 
Removal/Installation 
I 
PAR07 00-10-7 or 00-10-9 (from S/N 
10001 thru 10015 and 10027) 
Connection Of External Hydraulic 
Power 
I, II 
PAR08 00-10-8 or 00-10- 10 (from S/N 
10001 thru 10015 and 10027) 
Disconnection Of External 
Hydraulic Power 
I, II 
PAR09 67-00-30 or 67-00-31 (from 
S/N 10001 thru 10015 and 
10027) 
Tail rotor control system 
adjustment 
II 
PAR10 CPCP 20-70-10 Application of solid lubricant film IV 
2) ACRONYMS 
AMDI Aircraft Material Data Information  
AR As Required 
CPCP Corrosion Protection and Control Publication 
DOA Design Organization Approval 
IPC Illustrated Parts Catalogue 
LHD Leonardo Helicopters 
MM Maintenance Manual 
MMH Maintenance Man Hours 
P/N Part Number 
PTUM Pictorial Tools Usage Manual 
SB Service Bulletin 
3) ANNEX 
Annex A AW109 TR shaft localized penetrant inspection Type 1, Method C, Level 
2, Form “d”. 
Annex B AW109 TR sleeve assy bushing replacement. 
Annex C S.B. N°109K-074 Inspection form.

### Page 5

S.B. N°109K-074 ALERT 
DATE: April 26, 2021 
REVISION: / Page 5 of 33 
J. PUBLICATIONS AFFECTED 
N.A. 
K. SOFTWARE ACCOMPLISHMENT SUMMARY 
N.A.

### Page 6

S.B. N°109K-074 ALERT 
 DATE: April 26, 2021 
Page 6 of 33 REVISION: / 
2. MATERIAL INFORMATION 
A. REQUIRED MATERIALS 
1) PARTS 
PART I 
N.A. 
PART II 
N.A. 
PART III 
# P/N ALTERNATIVE P/N DESCRIPTION Q.TY LVL NOTE LOG P/N 
1 109-0133-07-101  Bushing 1 .  - 
PART IV 
N.A. 
Refer also to IPC for the spares materials required to comply with the MM Paragraphs 
referenced in the accomplishment instructions. 
2) CONSUMABLES 
The following consumable materials, or equivalent, are necessary to accomplish this 
Service Bulletin: 
# Spec./LHD code number DESCRIPTION Q.TY NOTE PART 
2 SAE-AMS-2644, Type I,  Method C, Level 2 Dye Penetrant AR (1)(2) I 
3 SAE-AMS-2644, Type I, Form “d” Developer AR (1)(2 ) I 
4 SAE-AMS-2644 Cl II Solvent (C290) AR (1)(2) I 
5 ASTM D740, Type I Methyl-ethyl-ketone (C511) AR ( 1) I, III 
6 Commercial Plastic bristled brush AR (1) I 
7 Commercial Aluminum adhesive tape AR (1) I 
8 Commercial Small soft clean brush AR (1) I 
9 Commercial Clean, dry, lint-free cloth or  absorbent toweling AR (1) I 
10 MIL-L-23398 Type IV Solid film, lubricant AR (1)  I, IV 
11 Commercial Aluminium oxide, 80-grit (C208) AR (1 ) III 
12 199-05-002, Type II, Class 2 Adhesive, (C054) AR  (1) III 
13 Commercial Cloth, soft lint-free (C011) AR (1) I II 
14 MIL-PRF-680, Type II Cleaning solvent (C287) AR (1) III 
Refer also to AMDI for the consumable materials require d to comply with the MM 
Paragraphs referenced in the accomplishment instructions.

### Page 7

S.B. N°109K-074 ALERT 
DATE: April 26, 2021 
REVISION: / Page 7 of 33 
3) LOGISTIC MATRIX 
N.A. 
NOTE 
 Local supply. 
 This material shall be certified in accordance with A MS2644, obtained from a 
supplier listed in QPL-AMS2644, supplied from the same manufacturer and in 
aerosol cans packaging. 
B. SPECIAL TOOLS 
# P/N DESCRIPTION Q.TY NOTE PART 
15 109-3130-32-1 Tail rotor retaining nut wrench 1 (B1) I 
16 895-3130-02-101 Tool, T/R slider bushing install ation 1 (B1) I 
17 109-3130-53-111 Tool, T/R pitch change slider ring nut removal/installation 1 (B1) I 
18 109-3130-54-101 or 109-3130-54-111 Tool, T/R pitch change housing ring nut removal/installation 1 (B1) I 
19 109-3130-70-101 Tool, T/R pitch change housing duplex bearing removal 1 (B1) I 
20 109-3130-69-101 Tool, T/R pitch change housing duplex bearing installation 1 (B1) I 
21 109-3130-71-101 Tool, T/R pitch change slider in stallation  1 (B1) I 
22 109-3130-55-117 Tool, T/R pitch change slider re moval 1 (B1) I 
23 Commercial Endoscope 1 (B2)(B2) I 
24 Commercial Dark curtain 1 (B2) I 
25 Commercial Magnifying lens 5x 1 (B2) I 
26 Commercial UV-A inspection lamp 1 (B2)(B3) I 
27 Commercial UV-A/White light meters 1 (B2) I 
28 Commercial Hydraulic system test bench 1 (B2) I,  II 
29 Metal sheet 55x5 mm,  thickness 1 mm. Bushing displacement  measuring tool 1 (B4)(B5) I, II 
30 Commercial Environmental thermometer 1 (B2) I 
31 Commercial Parallel lathe 1 (B2) III 
32 Commercial Caliper 1 (B2) III 
33 Commercial Dry abrasive blasting equipment 1 (B2 ) III 
Refer to PTUM for the special tools required to comply  with the MM Paragraphs 
referenced in the accomplishment instructions. 
Refer also to Annex A for the equipment/tools require d for the liquid penetrant 
inspection. 
Refer also to Annex B for the equipment/tools require d for the sleeve assy bushing 
replacement.

### Page 8

S.B. N°109K-074 ALERT 
 DATE: April 26, 2021 
Page 8 of 33 REVISION: / 
SPECIAL TOOLS NOTE 
 Please contact Leonardo Helicopters Division order adm inistration to request the 
tools supply on loan. As soon as the present Service Bull etin is implemented the 
tools supplied on loan shall be promptly returned to Leonardo Helicopters Division. 
 Item to be procured as local supply. 
 This lamp should emit at least 1200 µW/cm² and no more than 20lux at 38cm from 
the front of the filter to the face of the sensor. 
 Local manufacturing in accordance instructions given in Part I. 
 The metal sheet specifications may be different. For reference, some examples are 
given: 2024 T3 AMS-QQ-A-250/4; 2024 T3 AMS-QQ-A-250 /5; CRES 301 ¼ H, 
AMS5517. 
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 b e eligible to receive REQUIRED 
MATERIALS on free of charge basis, except for Consumable  Materials and Special 
Tools. 
NOTE 1: Customers who fail to comply with the instruct ions 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 accompanied by 
INSPECTION REPORT and PICTURE of the affected area. 
NOTE 2: The INSPECTION REPORT and PICTURE are mandatory; in case the MMIR 
is not accompanied by these documents, it will be rejected.

### Page 9

S.B. N°109K-074 ALERT 
DATE: April 26, 2021 
REVISION: / Page 9 of 33 
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) All lengths are in mm. 
PART I 
1. In accordance with MM Paragraph 00-20-1, prepare t he helicopter on ground for a safe 
maintenance. Disconnect the battery, all electrical pow er sources and/or the external 
power supply. 
2. Gain access to the plug P/N 109-0133-18-103 (or P/N 109-0130-85-1) installed on the tail 
rotor hub removing balance flange and all the necessary components. Mark the installation 
position of the balance masses in order to reinstall them in the same location and reduce 
time for the TR balancing required at the end of the  reassembly. Retain all the 
components. 
3. In accordance with Figure 3, verify that plug P/N 1 09-0133-18-103 (or P/N 109-0130-85-
1) is torqued at 59÷69 Nm. 
3.1 Record the torque value on the annexed Detailed Inspection Form and proceed 
with next step. 
4. In accordance with MM Paragraph 64-00-15 or 64-00-1 7 (from S/N 10001 thru 10015 and 
10027) or 64A-00-16 or 64A-00-18 (from S/N 10001 th ru 10015 and 10027), remove the 
tail rotor hub and blade assy. 
NOTE 
Before the removal of the TR sleeve as per MM 
Paragraph 64-30-5 or 64-31-6 (from S/N 10001 thru 
10015 and 10027), check the bushing P/N 109-0133-
07-101 for condition and bonding. In case it is found 
partially or completely displaced from its seat, before  
and after its removal, take pictures of bushing and 
sleeve, record the finding on the Detailed Inspection 
Form and proceed with the following step. 
5. In accordance with MM Paragraph 64-30-5 or 64-31-6  (from S/N 10001 thru 10015 and 
10027), remove the pitch change mechanism.

### Page 10

S.B. N°109K-074 ALERT 
 DATE: April 26, 2021 
Page 10 of 33 REVISION: / 
6. In accordance with MM Paragraph 64-30-7 or 64-31-8  (from S/N 10001 thru 10015 and 
10027), inspect the removed tail rotor sleeve assy P/N 109-0130-90-117/-121 and bushing 
P/N 109-0133-07-101. Inspect the bushing in the tail rotor sleeve assy for debonding. 
6.1 In case anomalies are detected, take pictures of the affected bushing and sleeve, 
record the findings on the Detailed Inspection Form, a nd contact Leonardo 
Helicopters to evaluate part serviceability. If necessary , in accordance with MM 
Paragraph 64-30-5 or 64-31-6 (from S/N 10001 thru 10015 and 10027), replace it 
with a serviceable TR Sleeve. In the meantime, proceed with step 7. 
6.2 In case of no findings, proceed to next step. 
7. With reference to Figure 1 and Figure 2 detail A,  gain access to tail rotor shaft assy P/N 
109-0445-08-(all dashes) and: 
CAUTION 
Pay particular attention to not damage the Tail Roto r 
Shaft Assy with the endoscope probe during the 
inspection. 
7.1 perform internal surface endoscope inspection for a bnormal wear condition, 
corrosion, fretting, crack and damage; 
7.2 perform external surface visual inspection for abnor mal wear condition, corrosion, 
fretting, crack and damage; 
7.3 with reference to Figure 1 and Figure 2 detail B , in accordance with Annex A, 
perform surface Fluorescent Penetrant Inspection on the indicated area; 
7.4 if no evidence of existing anomalous wear, corrosio n, fretting, damage or crack is 
found, proceed to step 8; 
7.5 if evidence of anomalous wear, corrosion, fretting , damage or crack is found, take 
relevant pictures, record the findings on the Detailed Inspection Form and contact 
Leonardo Helicopters to evaluate part serviceability. If necessary, in accordance 
with MM Paragraph 65-20-5 or 65-21-6 (from S/N 1000 1 thru 10015 and 10027), 
replace it with a serviceable 90-Degree Gearbox. 
NOTE 
Do not attach aft boot to pitch change slider assy. 
8. In accordance with MM Paragraph 64-30-5 or 64-31-6  (from S/N 10001 thru 10015 and 
10027), re-install previously removed pitch change mechanism. 
9. In accordance with MM Paragraph 64-00-15 or 64-00-1 7 (from S/N 10001 thru 10015 and 
10027) or 64A-00-16 or 64A-00-18 (from S/N 10001 th ru 10015 and 10027), re-install 
previously removed tail rotor hub and blade assy. 
10. In accordance with MM Paragraph 00-10-7 or 00-10- 9 (from S/N 10001 thru 10015 and

### Page 11

S.B. N°109K-074 ALERT 
DATE: April 26, 2021 
REVISION: / Page 11 of 33 
10027), connect the hydraulic test bench to the helicopter and operate it at 103.5 bar (1500 
psi). 
CAUTION 
One assistant must position and hold right anti torque 
pedal full forward before beginning the following 
procedure. 
11. In accordance with Figure 4, manufacture on site th e bushing displacement measuring 
tool following the next steps: 
11.1 Starting from a metal sheet of 55x5 mm (1 mm th ickness), bend it to obtain an “L” 
shape with the size indicated in Figure 4. 
11.2 In accordance with Figure 4 Detail E, insert the t ool between pitch change slider 
assy and tail rotor shaft assy until reaching the bushing of the TR sleeve assy. 
CAUTION 
After trimming, remove all swarf and sharp edges to 
avoid to scratch the tail rotor shaft assy. 
11.3 If gap is present between the vertical leg of the  tool and the pitch change slider 
assy, start trimming the short segment until gap is removed. 
11.4 Record the dimension of the tool and retain it f or Part II inspection. 
12. With reference to Figure 3, attach aft boot P/N 1 09-0130-96-101 on pitch change slider 
assy. 
13. Return the anti torque pedal to center. In accorda nce with MM Paragraph 00-10-8 or 00-
10-10 (from S/N 10001 thru 10015 and 10027), disconnect the hydraulic test bench from 
the helicopter. 
14. Return the helicopter to a ready to flight condition and record for compliance with Part I of 
this Service Bulletin on the helicopter logbook. 
NOTA 
Send the Detailed Inspection Form and pictures with 
Subject line “ASB 109K-074 - S/N XXXXX – Compliance 
to Part I”. “XXXXX” is the helicopter S/N. 
15. Send the attached compliance form and the pictures  taken during the inspections to the 
following mail box: 
 engineering.support.lhd@leonardocompany.com 
As an alternative, gain access to My Communications section on Leonardo WebPortal and 
compile the “Service Bulletin Application Communication”.

### Page 12

S.B. N°109K-074 ALERT 
 DATE: April 26, 2021 
Page 12 of 33 REVISION: / 
PART II 
NOTE 
If tail rotor controls adjust procedure (ref. 67-00-30  or 
67-00-31 (from S/N 10001 thru 10015 and 10027)) has  
been performed after manufacturing the Bushing 
displacement measuring tool, discard the previous tool 
and manufacture a new one i.a.w. Part I, step 11. 
1. In accordance with MM Paragraph 00-20-1, prepare t he helicopter on ground for a safe 
maintenance. Disconnect the battery, all electrical pow er sources and/or the external 
power supply. 
2. In accordance with MM Paragraph 00-10-7 or 00-10-9  (from S/N 10001 thru 10015 and 
10027), connect the hydraulic test bench to the helicopter and operate it at 103.5 bar (1500 
psi). 
CAUTION 
One assistant must position and hold right anti torque 
pedal full forward before beginning the following 
procedure. 
3. With reference to Figure 3, detach aft boot from p itch change slider assy. 
4. With reference to Figure 4, move aft boot and, usi ng bushing displacement measuring 
tool, verify that the distance from bushing to pitch ch ange slider assy has not changed 
since last inspection. If the distance decreases (long side of tool not in contact with slider 
assy, ref. Figure 4 Detail E), proceed as follows, otherwise proceed to step 5: 
4.1 In accordance with MM Paragraph 00-10-8 or 00-10-1 0 (from S/N 10001 thru 
10015 and 10027), disconnect the hydraulic test bench from the helicopter. 
4.2 Gain access to the plug P/N 109-0133-18-103 (or P/ N 109-0130-85-1) installed on 
the tail rotor hub removing balance flange and all the necessary components. Mark 
the installation position of the balance masses in order to reinstall them in the same 
location and reduce time for the TR balancing required  at the end of the 
reassembly. Retain all the components. 
4.3 In accordance with Figure 3, verify that plug P/N 109-0133-18-103 (or P/N 109-
0130-85-1) is torqued at 59÷69 Nm. 
4.4 Record the torque value on the Detailed Inspectio n Form and proceed with next 
step. 
4.5 In accordance with MM Paragraph 64-00-15 or 64-00- 17 (from S/N 10001 thru 
10015 and 10027) or 64A-00-16 or 64A-00-18 (from S/ N 10001 thru 10015 and 
10027), remove the tail rotor hub and blade assy.

### Page 13

S.B. N°109K-074 ALERT 
DATE: April 26, 2021 
REVISION: / Page 13 of 33 
4.6 In accordance with MM Paragraph 64-30-5 or 64-31-6  (from S/N 10001 thru 10015 
and 10027), remove the pitch change mechanism. 
4.7 On the tail rotor sleeve assy P/N 109-0130-90-117/ -121 before its removal, inspect 
the bushing P/N 109-0133-07-101 for correct installation and debonding 
4.7.1 In case the bushing is not found in the correct pos ition or it is debonded 
so that can be moved off from its seat, take pictures of the bushing and 
sleeve, record the findings on the Detailed Inspection Form and replace 
the bushing in accordance with part III. If necessary, in accordance with 
MM Paragraph 64-30-5 or 64-31-6 (from S/N 10001 thr u 10015 and 
10027), replace the TR sleeve with a serviceable part. 
4.7.2 In case of no findings, verify the bushing displa cement measuring tool 
as per Part I, step 11. 
4.8 In accordance with MM Paragraph 64-30-5 or 64-31-6  (from S/N 10001 thru 10015 
and 10027), re-install previously removed pitch change mechanism. 
4.9 In accordance with MM Paragraph 64-00-15 or 64-00- 17 (from S/N 10001 thru 
10015 and 10027) or 64A-00-16 or 64A-00-18 (from S/ N 10001 thru 10015 and 
10027), re-install previously removed tail rotor hub and blade assy. Proceed to step 
7. 
5. With reference to Figure 3, attach aft boot P/N 10 9-0130-96-101 on pitch change slider 
assy. 
6. Return anti torque pedal to center. In accordance w ith MM Paragraph 00-10-8 or 00-10-
10 (from S/N 10001 thru 10015 and 10027), disconnect the hydraulic test bench from the 
helicopter. 
7. Return the helicopter to a ready to flight conditi on and record for compliance with Part II 
of this Service Bulletin on the helicopter logbook. 
NOTA 
Send the Detailed Inspection Form and pictures with 
Subject line “ASB 109K-074 - S/N XXXXX – Compliance 
to Part II”. “XXXXX” is the helicopter S/N. 
8. Send the attached compliance form and the pictures taken during the inspections to the 
following mail box: 
 engineering.support.lhd@leonardocompany.com 
As an alternative, gain access to My Communications section on Leonardo WebPortal and 
compile the “Service Bulletin Application Communication”.

### Page 14

S.B. N°109K-074 ALERT 
 DATE: April 26, 2021 
Page 14 of 33 REVISION: / 
PART III 
1. In accordance with MM Paragraph 00-20-1, prepare t he helicopter on ground for a safe 
maintenance. Disconnect the battery, all electrical pow er sources and/or the external 
power supply. 
2. In accordance with MM Paragraph 64-00-15 or 64-00-1 7 (from S/N 10001 thru 10015 and 
10027) or 64A-00-16 or 64A-00-18 (from S/N 10001 th ru 10015 and 10027), remove the 
tail rotor hub and blade assy. 
3. In accordance with MM Paragraph 64-30-5 or 64-31-6  (from S/N 10001 thru 10015 and 
10027), remove the pitch change mechanism. 
4. In accordance with Annex B, replace the bushing P/N 1 09-0133-07-101. 
5. In accordance with MM Paragraph 64-30-5 or 64-31-6  (from S/N 10001 thru 10015 and 
10027),  re-install previously removed pitch change mechanism. 
6. In accordance with MM Paragraph 64-00-15 or 64-00-1 7 (from S/N 10001 thru 10015 and 
10027) or 64A-00-16 or 64A-00-18 (from S/N 10001 th ru 10015 and 10027), re-install 
previously removed tail rotor hub and blade assy. 
7. Return the helicopter to a ready to flight conditi on and record for compliance with Part III 
of this Service Bulletin on the helicopter logbook. 
8. Send the attached compliance form to the following mail box: 
 engineering.support.lhd@leonardocompany.com 
As an alternative, gain access to My Communications section on Leonardo WebPortal and 
compile the “Service Bulletin Application Communication”.

### Page 15

S.B. N°109K-074 ALERT 
DATE: April 26, 2021 
REVISION: / Page 15 of 33 
PART IV 
1. During application of tail rotor gearbox 400 FH s cheduled inspection, with reference to 
Figure 2 Detail B, verify the presence of solid film lubricant on “inspection area” (it should 
be present only on the “4.0mm section” and on vertical  side of shoulder). If necessary, 
restore the layer of solid film lubricant MIL-L-23398 Type IV as follows: 
1.1 Mask off surrounding areas near the inspection zone (Figure 2, Detail B) with 
adhesive Aluminium tape. 
1.2 Clean the part with a clean cloth soaked with Class 2 solvent listed in QPL-AMS-
2644. 
1.3 In accordance with CPCP 20-70-10, touch up where ne cessary with solid film 
lubricant with MIL-L-23398 Type IV product. 
2. Record for compliance with Part IV of this Service Bu lletin on the helicopter logbook. 
3. Send the attached compliance form to the following mail box:  
 engineering.support.lhd@leonardocompany.com 
As an alternative, gain access to My Communications section on Leonardo WebPortal and 
compile the “Service Bulletin Application Communication”. 
 
  Non cancellare mai questo segnalibro Non cancellare mai interruzione sezione

### Page 16

Figure 1 
 S.B. N°109K-074 ALERT 
 DATE: April 26, 2021 
Page 16 of 33 REVISION: /

### Page 17 (OCR)

K LEONARDO
HELICOPTERS
INSPECTION AREA
DETAIL B
PARTS OMIT ER FOR TO FIGURE ANITY PURPOSE
150.0
INSPECTION AREA
150.0
DETAIL A
PARTS OMITTED FOR BETTER CLARITY PURPOSE
(REFER TO FIGURE 1)
Figure 2
S.B. N°109K-074 ALERT
DATE: April 26, 2021
REVISION: /  Page 17 of 33

### Page 18

Figure 3 
 S.B. N°109K-074 ALERT 
 DATE: April 26, 2021 
Page 18 of 33 REVISION: / 
 
  
ROTATION
109-0133-18-103 PLUG (REF)
TORQUE 59÷69 Nm
VIEW C
TAIL ROTOR INSTALLATION
STRUCTURE AND SYSTEMS ARE PARTIALLY OMITTED FOR BETTER CLARITY PURPOSE
VIEW C
STRUCTURE AND SYSTEMS ARE PARTIALLY OMITTED 
FOR BETTER CLARITY PURPOSE
109-0130-90-117/-121
TR SLEEVE ASSY (REF)
109-0130-98-101 AFT BOOT (REF)
109-0130-91-(ALL DASHES)
PITCH CHANGE SLIDER ASSY (REF)
REF
DETAIL D

### Page 19

Figure 4 
S.B. N°109K-074 ALERT 
DATE: April 26, 2021 
REVISION: / Page 19 of 33 
  
TRIM AREA
DETAIL E
STRUCTURE AND SYSTEMS ARE PARTIALLY OMITTED 
FOR BETTER CLARITY PURPOSE
109-0130-91-(ALL DASHES)
PITCH CHANGE SLIDER ASSY (REF)
DETAIL D
STRUCTURE AND SYSTEMS ARE PARTIALLY OMITTED 
FOR BETTER CLARITY PURPOSE
109-0130-90-117/-121
TR SLEEVE ASSY (REF)109-0133-07-101
BUSHING (REF)
BUSHING DISPLACEMENT
MEASURING TOOL
POINT OF CONTACT
DETAIL E
BUSHING DISPLACEMENT 
MEASURING TOOL
40 mm (REF)
15 mm (REF)

### Page 20

ANNEX A 
 S.B. N°109K-074 ALERT 
 DATE: April 26, 2021 
Page 20 of 33 REVISION: / 
ANNEX A 
AW109 TR SHAFT LOCALIZED  
PENETRANT INSPECTION 
TYPE 1, METHOD C, LEVEL 2, FORM “d”

### Page 21

ANNEX A 
S.B. N°109K-074 ALERT 
DATE: April 26, 2021 
REVISION: / Page 21 of 33 
1 PURPOSE AND APPLICABILITY 
This procedure details the requirements for the Liquid Penetrant Inspection (PT) on the 
Tail Rotor Shaft Assy. The specific Penetrant system to b e used is Type I, Method C, 
Sensitivity Level 2, form “d”. Purpose of this inspecti on is the detection of any possible 
crack located on a specific surface of the tail rotor shaft assy. 
2 REFERENCES 
The following documents in their last revision are considered part of this procedure: 
ASTM E1417  Standard Practice for Liquid Penetrant Te sting; 
ASTM E3022 Standard Practice for Measurement of Emission  Characteristics and 
Requirements for LED UV-A Lamps Used in Fluorescent Penetrant 
and Magnetic Particle Testing; 
EN4179/NAS410 Qualification and approval of personnel  for non-destructive testing; 
QPL AMS2644 Qualified Product List of Inspection Mate rials, Penetrant; 
SAE AMS2644 Inspection Materials, Penetrant. 
3 EQUIPMENT AND MATERIALS 
The following materials, equipment and tools are requested. 
3.1 MATERIALS 
WARNING 
SOLVENT CLEANERS AND DEVELOPER CARRIER 
FLUIDS ARE DANGEROUS. OBSERVE ALL 
RELEVANT SAFETY PRECAUTIONS TO PREVENT 
THE RISK OF INJURY, FIRE OR EXPLOSION. 
a. Dye Penetrant SAE-AMS-2644 TY I, Method C, Level  2 (*); 
b. Developer SAE-AMS-2644 Form “d” (*);  
c. Solvent SAE-AMS-2644 Class 2 (*).  
d. Methyl Ethyl Ketone (MEK) solvent.  
(*) All the materials shall be certified in accordance with AMS2644, obtained from a 
supplier listed in QPL-AMS2644, supplied from the same  manufacturer and in 
aerosol cans packaging. 
3.2 EQUIPMENT/TOOLS 
a. dark curtain;  
b. UV-A inspection lamp emitting at least 1200 µW/cm² a nd no more than 20lux at 
38cm from the front of the filter to the face of the sensor;

### Page 22

ANNEX A 
 S.B. N°109K-074 ALERT 
 DATE: April 26, 2021 
Page 22 of 33 REVISION: / 
c. UV-A/White light meters; 
d. plastic bristled brush; 
e. small soft clean brush;  
f. aluminum adhesive tape; 
g. clean, dry, lint-free cloth or absorbent toweling; 
h. a magnification lens (max 5X); 
i. an environmental thermometer.  
4 PERSONNEL 
All Personnel performing this inspection and reporting  results shall be approved to the 
appropriate level in accordance with EN4179/NAS410, or equivalent. The personnel shall 
also be familiar with the purpose of this procedure. 
5 INSPECTION INSTRUCTION 
5.1 PART PREPARATION 
Make sure that the temperature of the part to be insp ected is between 10°C and 
45°C degrees (50-113 Fahrenheit). 
WARNING 
USE OF ANY ABRASIVE MATERIALS OR TOOLS IS 
STRICTLY FORBIDDEN. 
Mask off surrounding areas near the inspection zone (F igure 2, Detail B) with 
adhesive Aluminium tape and remove dry film lubricant using both MEK and plastic 
bristled brush taking care to the area of the shoulder and related fillet radius. 
Make sure that dry film lubricant is fully removed fro m all the inspection area and 
that part surface is degreased and dry. Clean white paper can be used to prove the 
complete removal of the dry film lubricant. 
5.2 PENETRANT APPLICATION 
NOTE 
Do not spray the liquid penetrant directly on the 
inspection area. 
After the solvent (MEK) is completely evaporated, appl y Type 1, Method C, 
Sensitivity Level 2 liquid penetrant listed in QPL-AMS-2644 using a small soft clean 
dry brush. Take care to cover all the inspection area (Figure 2, Detail B). Penetrant 
Dwell Time shall be a minimum of 30 minutes and no more than 60 minutes.

### Page 23

ANNEX A 
S.B. N°109K-074 ALERT 
DATE: April 26, 2021 
REVISION: / Page 23 of 33 
5.3 PENETRANT REMOVAL 
Excess penetrant removal shall be performed by using clean dry “lint free” cloths (or 
paper). Darken the part and switch on UV-A light lamp to achieve irradiance not less 
than 100 µW/cm² on the working surface and ambient wh ite light illuminance not 
exceeding 100 lx. 
NOTE 
The surface of the component shall not be flushed with 
solvent and the cloth or towel shall not be saturated with 
solvent. 
Removal shall be performed by first wiping the excess penetrant with a clean, lint-
free, dry cloth or absorbent toweling and the remainder of the surface penetrant shall 
then be removed with a solvent-dampened lint-free cl oth or towel (solvent Class 2 
listed in QPL-AMS-2644). The masking tape can be remo ved before using the 
solvent-dampened cloth in order to achieve a better pe rformance in excess 
penetrant removal. The surface will dry immediately at completion of this phase. 
5.4 DEVELOPING 
CAUTION 
In case of any developer dripping, the part shall be 
carefully cleaned and the whole process repeated from 
“Part Preparation”. 
In case of exceeding 60 minutes, the part shall be 
carefully cleaned and the whole process repeated from 
“Part Preparation”. 
Shake Nonaqueous Developer can for at least 30 seconds a nd spray form “d” 
developer listed in QPL-AMS-2644 as a uniform thin coa ting over the entire 
inspection area. A correct application will result in a l ayer that gives an insight into 
the underlying metal. Development time shall be minimum 20 minutes and maximum 
60 minutes. 
5.5 EXAMINATION 
Fluorescent Penetrant examination shall be carried out in conditions of subdued 
background lighting (maximum illuminance 20 lux) using  UV-A inspection light 
source able to provide not less than 1200 µW/cm² at 38cm. 
Inspector’s vision shall be dark adapted for a minimum of  1 min prior to examining 
components.

### Page 24

ANNEX A 
 S.B. N°109K-074 ALERT 
 DATE: April 26, 2021 
Page 24 of 33 REVISION: / 
Inspectors shall not wear photochromic or permanently da rkened lenses while 
processing or reviewing parts under UV-A light. 
The use of magnifying lens (5x) to support the interpr etation of liquid penetrant 
indications is recommended. 
5.6 EVALUATION 
In case any crack-like indication, considered as relevant indication, is found, contact 
Leonardo Helicopters for instructions. 
5.7 POST INSPECTION CLEANING 
At the end of the inspection, in case of no finding, ca refully clean the part from any 
residual of the products used with a clean cloth soaked with Class 2 solvent listed in 
QPL-AMS-2644. 
In accordance with CPCP 20-70-10, restore solid film lu bricant MIL-L-23398 Type 
IV in the area of inspection. 
6 RECORDS 
Report the result of the inspection as necessary using pertinent documentation.

### Page 25

ANNEX B 
S.B. N°109K-074 ALERT 
DATE: April 26, 2021 
REVISION: / Page 25 of 33 
ANNEX B 
AW109 TR SLEEVE ASSY  
BUSHING REPLACEMENT

### Page 26

ANNEX B 
 S.B. N°109K-074 ALERT 
 DATE: April 26, 2021 
Page 26 of 33 REVISION: / 
1 PURPOSE AND APPLICABILITY 
This procedure details the instructions to replace the bushing P/N 109-0133-07-101 of 
the TR Sleeve Assy. This procedure has to be performed b y qualified maintenance 
personnel in authorized facilities. 
2 EQUIPMENT AND MATERIALS 
The following materials, equipment and tools are requested. 
2.1 MATERIALS 
WARNING 
SOLVENT FLUID IS DANGEROUS. OBSERVE ALL 
RELEVANT SAFETY PRECAUTIONS TO PREVENT 
THE RISK OF INJURY, FIRE OR EXPLOSION. 
a. Bushing P/N 109-0133-07-101;  
b. Aluminium oxide, 80-grit (C208);  
c. Adhesive 199-05-002, Type II, Class 2 (C054);  
d. Cloth, soft lint-free (C011);  
e. Cleaning solvent MIL-PRF-680, Type II (C287).  
2.2 EQUIPMENT/TOOLS 
a. Parallel lathe; 
b. Caliper; 
c. Dry abrasive blasting equipment; 
3 INSPECTION INSTRUCTION 
NOTE 
The tail rotor sleeve assy P/N 109-0130-90-117/-121 is 
considered already removed from the helicopter as per 
applicable MM. 
3.1 Put the tail rotor sleeve assy P/N 109-0130-90-117 /-121 on an applicable work 
table. 
3.2 Visually examine the sleeve assy for damage. In case of evident signs of scratches, 
puncture or gouges, replace it. 
CAUTION 
Be careful to not damage the seat of the bushing in the 
sleeve.

### Page 27

ANNEX B 
S.B. N°109K-074 ALERT 
DATE: April 26, 2021 
REVISION: / Page 27 of 33 
NOTE 
To decrease the thickness of the bushing, perform the 
operation in different steps in order not to exceed t he 
internal diameter of 35.42 thru 35.52 mm. 
NOTE 
If a parallel lathe is not available, a screwdriver can  be 
used as alternative. Be careful not to damage the 
sleeve. 
3.3 Proceed to decrease the thickness of the bushing, in the sleeve, with a parallel 
lathe to remove the bushing and the adhesive. Remove and discard the bushing. 
NOTE 
Use an applicable light source, a mirror and a scriber to 
perform next step. 
3.4 With reference to Figure B1, Detail F, examine t he mating surface between the 
sleeve and the tail rotor shaft assy (X Area), for wear  and stepping. No wear or 
stepping is permitted. In case of any doubt, clean with the cleaning solvent MIL-
PRF-680, Type II and perform again the inspection. If  the presence of damage is 
confirmed, replace the sleeve. 
3.5 Verify that the internal diameter of the sleeve is 35.42 thru 35.52 mm. 
3.6 Prepare the sleeve and the new bushing P/N 109-01 33-07-101 for the bonding as 
follows: 
3.6.1 Clean the areas in contact of the sleeve and the bushing with vapour 
degreasing procedure or with the solvent ASTM D740, Ty pe I and the 
cloth, soft lint-free. 
3.6.2 Prepare the seat of the bushing in the sleeve wi th the dry abrasive 
blasting procedure. To do this, use the Aluminium oxide , 80-grit at a 
constant pressure of 345 thru 552 kPa. 
3.6.3 Clean again the areas in contact of the sleeve and the bushing with 
vapour degreasing procedure or with the solvent ASTM D740, Type I 
and the cloth, soft lint-free. 
CAUTION 
You must apply the adhesive within 4 hours from the 
cleaning. 
3.6.4 Apply a thin film of the adhesive 199-05-002, Type II, Class 2 on the seat 
of the bushing in the sleeve. 
3.6.5 Put the bushing into its seat in the sleeve.

### Page 28

ANNEX B 
 S.B. N°109K-074 ALERT 
 DATE: April 26, 2021 
Page 28 of 33 REVISION: / 
3.6.6 Make sure that the bushing is correctly installed and centered in its seat. 
3.6.7 Turn the bushing in its seat to make sure that th e adhesive is equally 
applied along all the internal surface. 
3.6.8 Verify the presence of an homogeneous squeeze o ut on the all the 
visible areas. 
3.6.9 Remove the unwanted adhesive. 
NOTE 
Ensure firm contact during curing time. 
NOTE 
An alternative curing cycle at a temperature of 60 °C 
thru 70 °C (140 °F thru 158 °F) for 2 hours is allowed. 
3.6.10 Let the adhesive to become hard at a temperatu re of 22 °C thru 26 °C 
(72 °F thru 79 °F) for 5-7 days or 80 °C thru 88 °C (176 °F thru 190 °F) 
for 1 hour. 
3.6.11 Ream the bushing internal diameter to 31.42 t hru 31.44 mm. 
3.7 If not already present, mark a letter “R” after S/N on sleeve assy.

### Page 29

ANNEX B 
S.B. N°109K-074 ALERT 
DATE: April 26, 2021 
REVISION: / Page 29 of 33

### Page 30

ANNEX C 
S.B. N°109K-074 ALERT 
 DATE: April 26, 2021 
Page 30 of 33 REVISION: / 
ANNEX C 
S.B. N°109K-074 INSPECTION FORM

### Page 31

ANNEX C 
S.B. N°109K-074 ALERT 
DATE: April 26, 2021 
REVISION: / Page 31 of 33 
Please send to the following address 
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 
DETAILED INSPECTION FORM DATE 
Number: S.B. N°109K-074 
Revision: / 
Customer Name and Address: Telephone: 
Fax: 
S.B. Compliance Date: 
Helicopter Model S/N Aircraft FH Sleeve FH T.S.O. 
     
Sleeve Assy P/N S/N 
  
Part I 
Paragraph Topic Remarks 
3.1 Torque Value [Nm]  
5 
Findings on TR 
 Sleeve Bushing  
P/N 109-0133-07-101 
(before sleeve removal) 
 
6 Findings on TR Sleeve P/N 109-0130-90    
6.1 
Findings on TR  
Sleeve bushing  
P/N 109-0133-07-101 
(after sleeve removal) 
 
7.5 TR Mast inspection results

### Page 32

ANNEX C 
S.B. N°109K-074 ALERT 
 DATE: April 26, 2021 
Page 32 of 33 REVISION: / 
ADDITIONAL REMARKS: 
 
 
 
 
 
 
 
NOTE 
Provide to LHD all the pictures taken during the inspection. 
FILLING NOTES 
 3.1 Record the tightening torque. 
 5 Brief description of the bushing status (e.g. Bonded and in place / Debonded and 
displaced) 
 6 Brief description of the defects found on the sleeve (e.g. No defects found / Wear / 
Fretting / Spalling…) 
 6.1 Brief description of the bushing status after detailed inspection (e.g. Bonded / 
Debonded) 
 7.5  Description of the findings of the Dye liquid penetrant inspection and of any other 
defect found (Wear, fretting, corrosion, spalling, cracks..)

### Page 33

ANNEX C 
S.B. N°109K-074 ALERT 
DATE: April 26, 2021 
REVISION: / Page 33 of 33 
Please send to the following address 
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 
DETAILED INSPECTION FORM DATE 
Number: S.B. N°109K-074 
Revision: / 
Customer Name and Address: Telephone: 
Fax: 
S.B. Compliance Date: 
Helicopter Model S/N Aircraft FH Sleeve FH T.S.O. 
     
Sleeve Assy P/N S/N 
  
Part II, III, IV 
Paragraph Finding/Compliance Date Remarks 
Part II   
Part III   
Part IV

### Page 34

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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