EASA AD No.: 2015-0213

TE.CAP.00110-004 © 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.: 2015-0213

Date: 16 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 accordance 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 operate 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):

ARRIEL 2 engines

TCDS Number: EASA E.001

Foreign AD: Not applicable

Supersedure: None

ATA 73

Engine Fuel & Control – Hydro-Mechanical Metering Unit –

Additional Check Valve and Constant Delta Pressure Valve 

Diaphragm – Replacement 

Manufacturer(s): Turbomeca

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

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

Helicopters AS 365 N3 and Airbus Helicopters Deutschland MBB-BK 117 D-2 

helicopters.

Reason: Fuel flow non-conformities were found during reception tests of ARRIEL 2E 

Hydraulic Mechanical Metering Unit (HMU). Investigation and instrumented 

tests revealed instabilities on the additional check valve. These instabilities lead 

to hydraulic pulses. All 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 73 2193 with instructions to 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.: 2015-0213

TE.CAP.00110-004 © European Aviation Safety Agency. All rights reserved. 2/2

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For the reasons described above, this AD requires replacement of the constant 

delta pressure valve and embodiment of Mod TU 193.

Effective Date: 30 October 2015

Required Action(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 replacing 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 2193.

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 replacement HMU on that engine, provided the HMU is 

a serviceable one (see Note 1 of this AD).

Ref. Publications: Turbomeca MSB 292 73 2193 version A dated 16 July 2015.

The use of later approved revisions of this 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 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 your usual or nearest TURBOMECA technical 

representative (refer to http://www.turbomeca-support.com).