Subject: 41/23 tooth bevel gear assembly of the accessory gearbox 

(module M01 ). 

Application of Tl No. 292 72 2849 or No. 292 72 2850 

referencing vibration check. 

The technical information contained in this document is approved under the Authority 

of Design Organization Approval No. EASA.21J.070. 

Date on which this Mandatory SB becomes effective and must systematically be complied with, 

according to the conditions of application. 

Applicable from NOVEMBER 2013 

If the resources (parts, tools, documentation, etc.) are available any earlier, the Mandatory SB may, 

be applied prior to the effectivity date. 

Version: C 

Reason for update: 

Accuracy on compliance conditions NOTES (paragraph 2.2). 

Applicable variants. ARRIEL 2 B-B1-B1A-B1B 

SB 292 72 2849 EN- C <June 18, 2014>- 1 I 10 
2.1. Required actions 

2.1.1. At the operator's site 

Application before the 31st of October 2016. 

Apply Tl Ref 292 72 2849 to check meshing vibration level of 41/23 tooth bevel gear of module M01 

according to paragraph 2.3. 

Consider the vibration check results: refer to paragraph 2.3.2.1.2. 

2.1.2. By a Maintenance Center 

Application before the 31 st of October 2016. 

Apply Tl Ref 292 72 2850 to check meshing vibration level of 41/23 tooth bevel gear of module M01 if 

task 71-02-15-760-801-A01 of the relevant ARRIEL 2 Maintenance Manual is applied: refer to paragraph 

2.3. 

2.2. Effectivity and compliance times 

ENGINE I VARIANT CODE CONDITIONS OF APPLICATION FOR ENGINES IN SERVICE 

ARRIEL 28-281-281A-2818 1-B Application before the 31 st of October 2016. 

Application of this Mandatory S8 is considered mandatory as a result of a technical requirement which might 

affect flight safety of engines in service. It may be done as defined by the effectivity code given in the table 

above. 

Note 1: This Mandatory S8 does not apply if a completed 41 tooth gear vibration check is indicated on the 

module M01 log card: 

- Reference to Service Letter (SL) No. 2892/13/ARRIEL2, 

- Or reference to Internal Directive (CI) No. 383952, 

- Or reference to Repair Technical Instruction (RTI) Ref. X 292 65 327 2, 

- Or reference to Airworthiness Directive (AD) No.2014-0036, 

- Or the log card is dated after January 31 , 2014, which corresponds to update of the acceptance CCT 

including the systematic vibratory check on bench. 

- Or if this Mandatory S8 was applied (all engine versions). 

- Or if the module M01 Serial Number is given below. 

Note 2: This Mandatory SB applies at a Maintenance Center if task 71-02-15-760-801-A01 of the relevant ARRIEL 2 

Maintenance Manual was already applied: see paragraph 2.3.1.2. 

List of modules M01 that are not concerned this Mandatory SB I (equivalent to figure 1, version B of this 

Mandatory SB) 

Variant S/N M01 Variant S/N M01 

28 124 281 1424 28 145 281 1509 28 162 281 1542 28 164 281 1654 28 482 281 1694 

28 507 281 1733 

28 536 281 1797 28 548 281 1891 

Applicable variants. ARRIEL 2 B-B1-B1A-B1B §2. 1/6 

SB 292 72 2849 EN- C <June 18, 2014>- 3/10 
WARNING: FAILURE TO APPLY THIS MANDATORY SERVICE BULLETIN MAY LEAD TO AN UNCOMMANDED IN-FLIGHT 

ENGINE SHUT-DOWN WHICH, ON A SINGLE-ENGINE HELICOPTER. MAY LEAD TO AN EMERGENCY 

AUTOROTATION LANDING. 

2.3.2.1. At the operator's site (equivalent to paragraph 6.B.(1 ), in version B of this Mandatory SB) 

2.3.2.1.1 . Apply Tl Ref 292 72 2849. 

2.3.2.1.2. Actions according to the vibration check result specified in the email sent by 

TURBOMECA or in the report generated by the B&K server: 

> Level 1 - Green indicator: keep module M01 in service. 

> Level 2- Yellow indicator: remove module M01 within 150 hours or 3 months 

(whichever is reached first). 

> Level 3- Orange indicator: remove module M01 within 25 hours (or earlier, 

depending on the recommendations made by TURBOMECA) or 3 months 

(whichever is reached first). 

2.3.2.1.3. 

> If "measure invalid", contact your TURBOMECA representative. 

Send an acknowledgement of receipt by email or fax to your NO RIA coordinator J /71-A j 

(refer to paragraph 2.4.3) confirming that the status of module M01 has been taken tt£-V' 

mto account. 

2.3.2.2. By a Maintenance Center 

If maintenance task 71-02-15-760-801-A01 of the relevant ARRIEL 2 Maintenance Manual is 

applied: 

2.3.2.2.1. Apply Tl Ref 292 72 2850. 

2.3.2.2.2. Actions according to the vibration check result: 

> Compliant result: release module MOl into service. 

> Non-compliant result: return module MOl to a Repair Cent er. 

2.3.3. Reconditioning and checks 

Perform a ground run check: refer to the relevant ARRIEL 2 Maintenance Manual, task 71-02-13-280-

801. 

. dentification 

2.3.4.1. At the operator's site 

2.3.4.1 .1. Record the application of this Mandatory SB on the module M01 log card indicating 

the measurement level as follows: "level 1 - green". "level 2 -yellow" or "level 3 -

orange", as well as the module M01 TSN at the time of the measurement. 

2.3.4.1.2. If necessary. notify TURBOMECA that standard exchange of module M01 has been 

performed by returning the fully completed compliance certificate (Appendix 2.1 ). 

2.3.4.2. By a Maintenance Center 

2.3.4.2.1. If the vibration check result is compliant, record the application of this Mandatory SB 

on the module M01 log card. 

2.3.4.2.2. If the vibration check result is not compliant, notify TURBOMECA that standard 

exchange of module M01 has been performed by returning the fully completed 

compliance certificate (Appendix 2.1). 

Applicable variants: ARRIEL 2 B-B1-B1A-B1 B §2- 3/6 

SB 292 72 2849 EN- C <June 18, 2014>- 5 I 10 
2.6.2. By a maintenance Center 

- Mechanic's standard tooling. 

- Refer to Tl Ref 292 72 2850. 

2.7. Weight and balance 

Not applicable. 

2.8. Publication references 

Document 

Maintenance Manual (MM) 

Spare Parts Catalog (SPC) 

Technical Instruction (TI) 

Service Letter (SL) 

Internal Directive (CI) 

Airworthiness Directive (AD) 

Repair Technical Instruction (RTI) 

Appl icable variants: ARRIEL 2 B-B1-B1A-B1B 

Engine Reference 

ARRIEL 28 X 292 M5 450 2 

ARRIEL 281 X 292 N5 450 2 ARRIEL 281A X 292 P4 450 2 

ARRIEL 28 X 292 M5 700 2 ARRIEL 281 X 292 N5 700 2 

ARRIEL 281A X 292 P4 700 2 

ARRIEL 28-281-281A 292 72 2849 292 72 2850 

ARRIEL 2 2892/13 

383952 

ARRIEL 1 & ARRIEL 2 2014-0036 

X 292 65 327 2 

§2- 5/6 

SB 292 72 2849 EN- C <June 18, 2014>- 7 I 10 
END of section §3 

"Application by a Maintenance Center qualified for level 3" 

Applicable variants: ARRIEL 2 B-B1-B1A-B1B §3- 1/1 

SB 292 72 2849 EN - C <June 18, 2014>- 9 I 10