EASA AD No : 2007 – 0109R1 

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EASA AIRWORTHINESS DIRECTIVE 

AD No : 2007-0109R1 

Date: 09 November 2009 

Note: This Airworthiness Directive (AD) is issued by EASA, acting in accordance with 

Regulation (EC) No 216/2008 on behalf of the European Community, its Member States 

and of the European third countries that participate in the activities of EASA under Article 

66 of that Regulation.

This AD is issued in accordance with EC 1702/2003, Part 21A.3B. In accordance with EC 2042/2003 Annex I, Part M.A.301, the 

continuing airworthiness of an aircraft shall be ensured by accomplishing any applicable ADs. Consequently, no person may 

operate an aircraft to which an AD applies, except in accordance with the requirements of that AD unless otherwise specified by

the Agency [EC 2042/2003 Annex I, Part M.A.303] or agreed with the Authority of the State of Registry [EC 216/2008, Article 

14(4) exemption]. 

Type Approval Holder’s Name : 

TURBOMECA 

Type/Model designation(s) : 

ARRIEL 2B, 2B1, 2B1A turboshaft 

engines 

TCDS Number: EASA.E.001 

Foreign AD: Not applicable 

Supersedure: This AD revises EASA AD 2007-0109, dated 19 April 2007 and corrected 20 

April 2007 

ATA 72 Engine – Module M03 (Gas Generator) – Turbine Blade 

Borescope Inspection/Replacement

Manufacturer(s): Turboméca, S.A. 

Applicability: All ARRIEL 2B, 2B1, 2B1A turboshaft engines, which do not incorporate 

modification TU166 (i.e.: Introduction of HP blade dampers). 

These engines are known to be installed on, but not limited to, the 

following helicopters: Eurocopter AS 350 B3, EC 130 B4 helicopters and 

Changhe Z11 helicopters. 

Reason: Several cases of Gas Generator Turbine (HP Turbine) blade rearward 

displacement have been detected during borescope inspection or in 

repair centre following engine disassembly. Two of them resulted in blade 

rubs between the rear face of the fir-tree roots and the rear bearing 

support cover. Further investigation revealed that these displacements 

were caused by the deformation or rupture of the blade locks. 

High HP blade rearward displacement can potentially result in blade 

release due to fatigue of the blade, which would cause an uncommanded 

in-flight engine shutdown. On a single-engine helicopter, the result may 

be an emergency autorotation landing or, at worst, an accident. 
EASA AD No : 2007 – 0109R1 

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AD 2007-0109 was issued requiring a periodic borescope inspection in 

order to detect HP blade rearward displacement, and, in case 

displacement was found above the specified limit, removal of Module 03. 

This precaution measure has been taken only on engine powering single 

engine rotorcraft. 

Since issuance of AD 2007-0109, Turboméca has released modification 

TU166 which consists in inserting HP blade dampers between the HP 

disc and the HP blade platform. Introduction of these dampers has 

demonstrated to limit axial displacement of the HP blade relative to the 

disk in case of blade lock rupture or opening, therefore eliminating the 

need for inspection and replacement. 

Therefore, this AD revises AD 2007-0109 by retaining the same 

requirements of AD 2007-0109 except that applicability is limited to 

ARRIEL 2B, 2B1 and 2B1A engines which do not incorporate modification 

TU166. 

Effective Date: 2007-0109 Revision 1: 23 November 2009 

2007-0109 Original Issue: 03 May 2007 

Compliance: If the engine does not incorporate modification TU166:

1. Perform the HP turbine inspection according to Mandatory Service 

Bulletin No. 292 72 2825 Version B, within 600 gas generator hours 

or 500 cycles (whichever comes first) of the previous HP turbine 

borescope inspection.

For Module 03 that have logged more than 600 hours or 500 cycles 

since new, repair or overhaul and for which the HP turbine 

borescope inspection was performed more than 600 hours or 500 

cycles ago, this inspection must be performed within 100 hours 

upon effective date of this AD. 

This inspection must be repeated within 600 gas generator hours or 

500 cycles (whichever comes first), or sooner as defined in 

paragraph 2.

2. Actions required following inspection: If inspections reveal HP blade 

rearward displacement, follow Mandatory Service Bulletin No. 292 

72 2825 Version B § 2.B to determine which action has to be taken. 

Depending on the blade rearward displacement result, the action 

will be either: 

 - Module 03 has to be removed 

 or 

 - Inspect again within the schedules defined in Mandatory Service 

Bulletin No. 292 72 2825 Version B § 2.B. 

3. After each inspection or replacement, the compliance certificate 

must be sent to Turboméca within 7 days, according to § 

2.D.(1)(a)3 or (c)3 of Mandatory Service Bulletin No. 292 72 2825 

Version B. 

If the engine incorporates modification TU166: No action is required. 

Ref. Publications: Turboméca S.A. Mandatory Service Bulletin 292 72 2825 Version B 

dated 21 September 2009. 

The use of later approved revisions of these documents is acceptable for 

compliance with the requirements of this AD. 
EASA AD No : 2007 – 0109R1 

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Remarks : 1. If requested and appropriately substantiated EASA can approve 

Alternative Methods of Compliance for this AD. 

2. The required actions and the risk allowance have granted the issuance 

of a Final AD with Request for Comments, postponing the public 

consultation process after publication. 

3. Enquiries regarding this AD should be referred to the Airworthiness 

Directives, Safety Management & Research Section, Certification 

Directorate, EASA. E-mail: ADs@easa.europa.eu. 

4. For any question concerning the technical content of the requirements 

in this AD, please contact: 

Turboméca, S.A., ARRIEL 2 Customer Support, 40220 TARNOS, 

FRANCE. Fax: +33 5 59 74 45 15; or contact your nearest technical 

representative at http://www.turbomeca-support.com).