EASA AD No.: 2010-0273R1

EASA Form 110 Page 1/3 

## EASA AIRWORTHINESS DIRECTIVE

AD No.: 2010-0273R1

Date: 16 February 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 b e ensured by accomplishing any applicable ADs. Cons equently, no person may operate an aircraft to which an AD applies, exc ept 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 :

Turboméca Type/Model designation(s) :

ARRIEL 1 series turboshaft engines

TCDS Number : EASA.E.073

Foreign AD : Not applicable

Revision: This AD revises EASA AD 2010-0273 dated 22 December 2010 which superseded

EASA AD 2010-0118 dated 18 June 2010.



### ATA 72 Engine – Module M03 (Gas Generator) – Second Stage Turbine Nozzle Guide Vane – Inspection/Replacement

Manufacturer(s): Turboméca S.A.

Applicability: Arriel 1B turboshaft engines, if mod ified by TU76 or TU202, and not modified by TU148, and fitted with repaired second stage Nozzle Guide Vane. These engines are known to be installed on, but not limited to Eurocopter AS350 series helicopters.

Reason: During quality inspections in repair centre some 2 nd stage Nozzle Guide Vanes (NGVs) to be installed on pre-TU148 standard Arriel 1B were found not conforming to the definition. The affected part s had been repaired and were found drilled on the rear flange instead of th e front flange. This configuration corresponds to 2 nd stage Turbine NGVs to be installed on post-TU148 standard Arriel 1B engines. This non com pliance may only be found on post-TU76 standard 2 nd stage Turbine NGVs (i.e. with flexible hub).
This non compliance would increase hot gas ingestio n and generate an increase of temperature in the Gas Generator (GG) t urbine rotor, potentially resulting in turbine damage and an uncommanded in-f light shutdown. On a single-engine helicopter, this could ultimately lea d to an emergency autorotation landing.
To detect and correct this unsafe condition, EASA A D 2010-0118 required accomplishing a daily check of the engine. Furtherm ore, it required contacting Turboméca for checking applicability and , if necessary, toEASA AD No.: 2010-0273R1

EASA Form 110 Page 2/3 inspect the 2 nd stage Turbine NGVs. If non serviceable parts were found, it required replacement with serviceable ones. It was previously known that modification TU202 was applicable only if TU76 was applied. However since issuance of EASA AD 2010-0118, it was found that some engines modified by TU202 did not e xplicitly have TU76 recorded on their log cards. Therefore these engine s were wrongly excluded from the applicability of EASA AD 2010-011 8, but they may also contain repaired 2nd stage Turbine NGVs affected by the same condition. As a result, EASA AD 2010-0273 extended the applica bility of EASA AD 2010-0118 to pre-TU148 and post TU-202 Arriel 1B en gines. This AD is revised to clarify the intent of paragra ph (6) of the “Required Actions and Compliance Time(s)” of the AD.

Effective Date: Revision 1: 02 March 2011 Original issue: 05 January 2011

Required Action(s) and Compliance Time(s): Required as indicated, unless accomplished previous ly: (1) Starting from 05 January 2011 [Effective Date o f EASA AD 2010-0273], perform a daily check (after last flight of the day ) of the free rotation of the gas generator, the autorotation time and the ab sence of noise in accordance with Par. 2.B(1)(a)3 of MSB A292 72 0829 version B and applicable Arriel 1B Maintenance Manual tasks 71-02 -09-760-801 and 05-20-01-200-801. If during any of these daily checks, any finding is identified in accordance with Par. 2.B(1)(a)3 of MSB A292 72 0829 version B, no further engine operation is allowed. (2) Within 7 days after 05 January 2011 [Effective Date of EASA AD 2010- 0273], send to Turboméca a copy of module M03 log c ard and identification sheet of the engine in accordance wi th the Mandatory Service Bulletin (MSB) A292 72 0829 version B. (3) If Turboméca confirm that MSB A292 72 0829 vers ion B is not applicable to the engine, no further action is requ ired for compliance with the requirements of this AD. (4) If Turboméca confirm that MSB A292 72 0829 vers ion B is applicable to the engine, within the compliance times indicated i n table 1 of this AD, inspect the 2 nd stage Turbine NGVs.

Table 1:

GG 1 st and/or 2 nd Stage Turbine Accumulated GG cycles on 05 January 2011 [Effective Date of EASA AD 2010-0273]: Compliance time: (1 st or 2 nd Stage Turbine Accumulated GG cycles)

Less than 1 200 (1 st and 2 nd Stage Turbine) Upon accumulating 1500 total GG cycles Equal or more than 1 200, and less than 1800 (1 st or 2 nd Stage Turbine) - Upon accumulating 300 GG cycles after 05 January 2011 [Effective Date of EASA AD 2010-0273], or - within 6 months after 05 January 2011 [Effective Date of EASA AD 2010-0273], whichever occurs first Equal or more than 1 800, and less than 2 400 (1 st or 2 nd Stage Turbine) - Upon accumulating 200 GG cycles after 05 January 2011 [Effective Date of EASA AD 2010-0273], or - within 4 months after 05 January 2011 [Effective Date of EASA AD 2010-0273], whichever occurs first Equal or more than 2 400, and - Upon accumulating 1 00 GG cyclesEASA AD No.: 2010-0273R1

EASA Form 110 Page 3/3 less than 3 000 (1 st or 2 nd Stage Turbine) after 05 January 2011 [Effective Date of EASA AD 2010-0273], or - Upon accumulating 3000 GG cycles on 1 st or 2 nd Stage Turbine, or - within 2 months 05 January 2011 [Effective Date of EASA AD 2010- 0273], whichever occurs first More than 3 000 (1 st or 2 nd Stage Turbine) Before next flight

Note 1: The life limit of the “monobloc” Gas Genera tor 2 nd stage turbine wheels affected by this AD is 3 000 cycles. (5) If during any inspection required by paragraph (4) of this AD, the 2 nd stage Turbine NGVs are found to be not compliant, b efore next flight, replace the affected Module M03 with a serviceable one, in accordance with Paragraph 2.B of MSB A292 72 0829 version B. (6) After 05 January 2011 [Effective Date of EASA A D 2010-0273], do not install a Module 03 with configuration post-TU76 an d pre-TU148 M03 and do not install a Module 03 with configuration post -TU202 and preTU148 M03, unless in compliance with the requiremen ts of this AD. (7) Replacement of Module M03 with a serviceable on e constitutes a terminating action for the requirements of this AD.

Ref. Publications: Turboméca Mandatory Service Bull etin (MSB) A292 72 0829 version B, dated 13 December 2010;

Arriel 1B Maintenance Manual X 292 65 452 1 / X 292 65 452 2 (French Version / English Version)
The use of later approved revisions of these docume nts 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. The required actions and the risk allowance have granted the issuance of a Final AD with Request for Comments, p ostponing the public consultation process after publication. 3. Enquiries regarding this AD should be referred t o the Airworthiness Directives, Safety Management & Research Section, C ertification 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 1 Customer Support, 40220 T ARNOS, FRANCE. Fax: +33 5 59 74 45 15 or contact your near est technical representative at www.turbomeca-support.com