EASA AD No.: 20 15

- 0 2 13

TE. CAP.0011 0

- 00 4 © European Aviation Safety Agency. All rights reserved. 1 / 2 Proprietary document. Copies are not controlled. Confirm revision status through the EASA

- Internet/Intranet. 

## EASA AIRWORTHINESS DIRECTIVE

AD No

. : 20 15

- 0 2 13

Date: 1 6 October 2015

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):

A RRIEL 2 e ngines

TCDS Number: EASA E.001

F oreign AD: Not applicable

Supersedure: None



### ATA 7 3 E ngine Fuel & Control

– Hydro

- Mechanical Metering Unit

–

Additional Check Valve and Constant Delta Pressure Valve Diaphragm

– Replacement

Manufacturer(s): T urbomeca

Applicability: ARRIEL 2 E and 2N engines, all serial numbers

. These engines are k nown to be installed on, but not limited to, Airbus Helicopter s AS 3 65 N3 and Airbus Helicopters Deutschland MBB

- BK 117 D

- 2 helicopters

.

Reason: Fuel flow n on

- conform ities were found during reception tests of ARRIEL 2E H ydraulic Mechanical M etering U nit (HMU)

. I nvestigation and instrumented tests revealed instabilities on the a dditional c heck v alve . These instabiliti es lead to hydraulic pulses

. A ll HMU installed on ARRIEL 2E and 2N engines could present these instabilities

. This condition, if not corrected , could lead to life reduction of the delta pressure valve diaphragm

, and consequently, an uncommanded engine power increase

, or an uncommanded in flight shutdown , possibly resulting in an emergency landing

. To address this unsafe condition, Turbomeca certified a new additional check valve with modification (Mod) TU 193 and issued Mandatory Service Bulletin ( MSB ) 292 7 3 2 193 with instructions t o replace the adjusted high / low pressure (HP/ LP ) fuel pump and metering valve assembly ( also known as HMU) with a post

- Mod TU193 unit and to replace the constant delta pressure valve diaphragm.EASA AD No.: 20 15

- 0 2 13

TE. CAP.0011 0

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

- Internet/Intranet. For the reasons described above, this AD requires replacement of the constant delta pressure valve and embodiment of Mod TU 193.

Effective Date: 3 0 October 2015

Required A ction(s) and Compliance Time(s) : Required as indicated, unless accomplished previously:
(1) For an engine in pre

- Mod TU 193 configuration

, before exceeding 880 HMU operating hours since new

, or during the next “800 hours periodical engine inspection”, whichever occurs first after the effective date of this AD

, modify the engine by replac ing the HMU with a serviceable HMU (see Note 1 of this AD) and replace the constant delta pressure diaphragm in accordance with the instructions of Turbomeca MSB 292 72 2 193

. Note 1: For the purpose of this AD , a serviceable HMU is one that embodies Mod TU 193

. ( 2 ) After modification of an engine as required by paragraph (1) of this AD, it is allowed to install a replaceme n t HMU on that engine, provided the HMU is a serviceable one (see Note 1 of this AD)

.

Ref. Public ations: Turbomeca MSB 292 7 3 2 193 version A dated 16 July 2015.

The use of later approved revisions of th is document 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 14 September 2015 as PAD 15

- 122 for consultation until 12 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 conte nt 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 TURBOMECA technical representative (refer to http://www.turbomeca

- support.com ).