EASA AD No : 20 1 5

- 0 2 11

TE. CAP.0011 0

- 00 4 © European Aviation Safety Agency. All rights reserved. 1 / 3 Proprietary document. Copies are not controlled. Confirm revision status through the EASA

- Internet/Intranet. 

## EASA AIRWORTHINESS DIRECTIVE

AD No

. : 20 15

- 0 2 1 1

Date: 1 5 October 20 1 5

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 EU 748/2012, Part 21.A.3B. In accordan ce with EU 1321/2014 Annex I, Part M.A.301, the continuing airworthiness of an aircraft shall be ensured by accomplishing any applicable ADs. Consequently, no person may ope rate an aircraft to which an AD applies, except in accordance with the requirements of that AD, unless otherwise specified by the Agency [EU 1321/2014 Annex I, Part M.A.303] or agreed with the Authority of the State of Registry [EC 216/2008, Article 14(4) exemption]

. 

### Design Approval Holder’s Name :


### TURBOMECA Type/Model designation(s) : ASTAZOU XIV engines

TCDS Number: EASA.E.075

F oreign AD : Not applicable

Supersedure : This AD supersedes EASA AD 20 10

- 0 004 dated 5 J anuary 20 10

.



### ATA 72 Engine

– Third Stage Turbine Wheel

– Inspection

Manufacturer(s): Turbom e ca

Applicability: ASTAZOU XIV B and XIV H engines, all serial numbers, if fitted with a third stage turbine wheel that incorporates modification AB 173 or modification AB 208, except those engines that have been reworked in accordance with the instructions of Turbomeca Serv ice Bulletin (SB) 283 72 0805.
These engines are known to be ins talled o n, but not limited to, Airbus Helicopters (formerly Aerospatiale, Sud Aviation) A louette III SA 319 B and GAZELLE SA 342 J helicopters.

Reason: Investigation of an uncommanded in

- flight shut down (IFSD) event revealed that a third stage turbine wheel rupture was not contained by the turbine casings. The released portion consisted of a turbine blade together with the rim piec e immediately below the blade. The rim piece was bounded by two adjacent axial slots and a fatigue crack that had developed between the holes in which the slots terminate. The slots and holes, which are closed by riveted plugs, were introduced by modification (MOD) AB 173 in order to improve the vibration characteristics of the turbine wheel. M OD AB 208 introduced an improvement to MOD AB 173 by changing only the riveting detail. Turbomeca issued SB 283 72 0805 to provide instructions for re

- boring the holes ( at overhaul or

re pair ) in order to improve their surface condition. A manufacturing process modification has been introduced to improve the surface condition of these holes in third stage turbine wheels. Wheels subject to the improved manufacturing process have serial numb ers ( S/Ns ) outside the range specified in Turbomeca M andatory S B (MSB) 283 72 0804 Version C

.
Although only one event has been reported which resulted in an uncommandedEASA AD No : 20 1 5

- 0 2 11

TE. CAP.0011 0

- 00 4 © European Aviation Safety Agency. All rights reserved. 2 / 3 Proprietary document. Copies are not controlled. Confirm revision status through the EASA

- Internet/Intranet. IFSD and no damage to the affected helicopter

, this condition, if not detected and corrected, could lead to an emergency autorotation landing

. To address the unsafe condition, EASA issued AD 2009

- 0136 to require inspection of certain third stage turbine wheels and removal of any damaged wheel. The wheels to be inspected were those that would exceed 2 000 cycles since new (CSN) by 01 February 2011

. Following additional research by Turbomeca on crack initiation and growth, EASA issued AD 2010

- 0004 , which superseded AD 2009

- 0136, to require new inspections

, based on new criteria

, and removal from service of any damaged wheel s

. Since EASA AD 2010

- 0004 was issued , a new case of crack ing on a third stage turbine wheel was detected during engine overhaul in a repair center . This turbine had previously bee n inspected in accordance with MSB 283 72 0804 Version C but the crack

, if present at that time, was not detected. Prompted by these findings, Turbomeca

, issued MSB 283 72 0804 Version D in order to expand the population of potentially affected turbines and to introduce repetitive inspection s

. For the reasons described above, this AD requires repetitive inspection s of the affected third stage turbine wheels, as specified in MSB 283 72 0804 Version D

, and

, depending on findings, accomplishment of the applicable corrective actions

.

Effective Date: 2 9 October 2015

Required A ction(s) and Compliance Time(s): Required as indicated unless accomplished previously:
Note 1: For the purpose of this AD, an affected third stage turbine wheel has a P/N and S/N as listed in Turbomeca MSB 283 72 0804 Version D

. (1) Within the compliance time specified in Table 1 of this AD, as applicable, and, thereafter, at intervals not to exceed 400 e ngine c ycles (EC), accomplish a dye penetrant inspection on the rear face of each affected third stage turbine w heel in accordance with the instructions of Turbomeca MSB 283 72 0804 Version D

.

Table 1

– Initial dye penetrant inspection

Engine condition (on the effective date of this AD) Compliance Time

Third stage turbine wheel installed, not affected by Turbomeca MSB 283 72 0804 Version C

Within 150 EC after the effective date of this AD Third stage turbine wheel installed, listed in Turbomeca MSB 283 72 0804 Version C

, and accumulated 300 EC or more sin c e last inspection , or since new, or since last overhaul , or repair, as applicable

Third stage turbine wheel installed, listed in Turbomeca MSB 283 72 0804 Version C

, and accumulated less than 300 EC sin c e the last inspection , or since new, or since last overhaul, or repair, as applicable Before exceeding 400 EC since the last inspection , or since new,

or since the last overhaul, or since repair, as applicable

Note 2: A non

- cumulative tolerance of 50 EC may be applied only to the inspection interval as specified in paragraph (1) of this AD.

(2) If , during any inspection as required by paragraph (1) of this AD

, a crack isEASA AD No : 20 1 5

- 0 2 11

TE. CAP.0011 0

- 00 4 © European Aviation Safety Agency. All rights reserved. 3 / 3 Proprietary document. Copies are not controlled. Confirm revision status through the EASA

- Internet/Intranet. detected , before next flight, remove the engine from the helicopter and contact Turbomeca for approved instructions.
(3) In

- shop rework of a third stage turbine on an engine in accordance with the instructions of Turbomeca SB 283 72 0805 constitutes a terminating action for the repetitive inspections as required by paragraph (1) of this AD for that engine

. ( 4 ) From the effective date of this AD, installation on an engine of an affected third stage turbine wheel is allowed, provided that, following installation, the engine is inspected as required by this AD.

Ref. Public ations : Turbom e ca MSB 283 72 0804 Version C dated 23 October 2009 , or Version D dated 24 July 2015

. Turbomeca SB 283 72 0805 Version B dated 15 December 2010

. The use of later approved revisions of th e s e document s is acceptable for compliance with the requirements of this AD.

Remarks : 1. If requested and appropriately substantiated, EASA can approve Alternative Methods of Compliance for this AD

. 2. This AD was posted on 15 September 2015 as PAD 15

- 124 for consultation until 13 October 2015. No comments were received during the consultation period

. 3. Enquiries regarding this AD should be referred to the Safety Information 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 : Operator Support ASTAZOU

- TURBOMECA 40220 TARNOS

– FRANCE Phone: +33 (0)5 59 74 40 00 Fax: +33 (0)5 59 74 45 15 or refer to your nearest TURBOMECA technical representative on http://www.turbomeca

- support.com

.