EASA AD No.: 2011-0218

EASA Form 110 Page 1/2 

## EASA AIRWORTHINESS DIRECTIVE

AD No.: 2011-0218

Date: 10 November 2011

Note: This Airworthiness Directive (AD) is issued b y EASA, acting in accordance with Regulation (EC) No 216/2008 on behalf of the Europe an Community, its Member States and of the European third countries that participat e 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 en sured by accomplishing any applicable ADs. Conseque ntly, no person may operate an aircraft to which an AD applies, except in accordance with the requirements of that AD unle ss 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 :
Turboméca Type/Model designation(s) :
ARRIEL 2 series engines

TCDS Number : EASA.E.001

Foreign AD : Not applicable

Supersedure : None



### ATA 72 Engine – Module M04 (Power Turbine) / Power Turbine Blades

– Life Limit / Replacement

Manufacturer(s): Turboméca S.A.
Applicability: Arriel 2B, 2B1, 2B1A, 2B1B engines, all serial numbers. These engines are known to be installed on, but not limited, to Eurocopter AS 350 B3, EC 130 B4, AS 350 C3 helicopters and Cha ngue Z11 helicopters.
Reason: During production of Arriel 2 Power Turbine (PT) wheels, Turboméca have detected geometric non-conformities on blade fir-tr ee roots. The technical investigations carried out by Turboméca have shown that this nonconformity is due to PT blade manufacturing and tha t only a limited number of PT blades are potentially affected. This situation, if not detected and corrected, may potentially lead to a reduction in the fatigue resistance of the PT blade s, which can reduce their in service use limit. This reduction of fatig ue resistance can potentially result in blade rupture, which could ca use an uncommanded inflight shut down, ultimately leading to an emergenc y autorotation landing for a single-engine helicopter. To address this unsafe condition, Turboméca have is sued Turboméca Mandatory Service Bulletin (MSB) A292 72 2842 versi on A, in which the life limit of those PT blades is reduced to 5 000 F light Cycles (FC). For the reasons stated above, this AD requires an i dentification of the installed PT blades, replacement of the affected bl ades before or uponEASA AD No.: 2011-0218

EASA Form 110 Page 2/2 accumulation of the new life limit. It prohibits as well installation of an affected PT blade on an installed engine or an engi ne to be installed, unless the PT blade is in compliance with the requi rements of this AD.

Effective Date: 24 November 2011
Required Action(s) and Compliance Time(s): Required as indicated, unless accomplished previous ly: (1) Within one month after the effective date of th is AD, identify if the M04 Power turbine wheel assembly has at least one insta lled PT blade having:

• a Part Number (P/N) 2 292 81 A01 0, and

• Serial Numbers (S/N) 102782 through 120230 inclusi ve or S/N 120293 through 120390 inclusive.
Note: The instructions for the identification of th e serial number of the PT blades of the module M04 are given in paragraph 2B( 1)(a) of Turboméca MSB A292 72 2842 version A. (2) If an affected PT blade is installed, concurren t to the identification as required by paragraph (1) of this AD, record the li fe limit of 5 000 FC for that PT blade in the module M04 log book and th e engine log book, in accordance with the instructions of paragr aph 2.B.(1)(b) of Turboméca MSB A292 72 2842 version A, and , upon or before accumulation of 5 000 FC by a PT blade since first installation on an engine, accomplish one of the following actions, in accordance with paragraphs 2.B.(1)(b) and 2.B.(2) of Turboméca MSB A292 72 2842 version A:

• Replace the PT blade with a serviceable PT blade;

• Replace the module M04 with a module M04 embodying serviceable PT blades;

• Replace the PT wheel assembly with a PT wheel asse mbly embodying serviceable PT blades. (3) From the effective date of this AD, do not inst all a PT blade as listed in paragraph (1) of this AD on an installed engine or an engine to be installed on a helicopter, unless the PT blade is i n compliance with the requirements of this AD.
Ref. Publications: Turboméca Mandatory Service Bull etin A292 72 2842 version A, dated 23 September 2011. The use of later approved revisions of this documen t is acceptable for compliance with the requirements of this AD.

Remarks : 1. If requested and appropriately substantiated, EA SA can approve Alternative Methods of Compliance for this AD. 2. This AD was posted on 10 October 2011 as PAD 11- 107 for consultation until 07 November 2011. The Comment Re sponse Document can be found at http://ad.easa.europa.eu

. 3. Enquiries regarding this AD should be referred t o the Safety Information Section, Executive Directorate, EASA. E -mail: ADs@easa.europa.eu

. 4. For any question concerning the technical conten t 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 your usual or nearest Tur boméca technical representative at www.turbomeca-support.com

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