EASA AD No.: 20 1 3

- 0 079

TE. CAP.00110

- 00 3 © 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 DI RECTIVE

AD No .: 20 1 3

- 0 079

Date: 22 March 201 3

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 EC 2042/2003 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 Age ncy [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) exemptio n]

.


### Design Approval Holder’s Name:

TURBOMECA Type/Model designation(s):
ARRIEL 2 engines

TCDS Number: EASA E.001

F oreign AD: Not applicable

Supersedure: This AD supersedes EASA AD 2012

- 0141 dated 31 July 2012.



### ATA 73 Engine Fuel & Control

– Hydro

- Mechanical Metering Unit

– Re placement

Manufacturer(s): Turboméca S.A.

Applicability: ARRIEL 2D engines, all serial numbers.

These engines are known to be installed on, but not limited to, Eurocopter AS 350 B3 and EC 130 T2 helicopters.

Reason: During an ARRIEL 2D endurance test, the illumination of the Low Fuel Pressure warning light was observed. The i nvestigation of the High Pressure / Low Pressure (HP/LP) pump assembly within the Hydro

- Mechanical Metering Unit (HMU) , removed following this o ccurrence, revealed a deterioration and a loss of the LP pump drive function

. This condition

, if not corrected, could lead to the illumination of the Low Fuel Pressure warning light in flight

, possibly resulting in an u ncommanded i n

- f light

s hut

- d own (if the booster pumps are not switched on or under high load factor manoeuvres). For a single

- engine helicopter, it may result in an emergency autorotation landing.

To address this potential unsafe condition

, EASA issued AD 2012

- 0141 to reduce the service life of the HMU, requiring replacement before exceeding a defined limit of operating hours

. Since that AD was issued, further cases of deterioration of HMU rotating components have been reported, which occurred before the replacement interval requi red by that AD.
Prompted by these findings, Turboméca revised M andatory S ervice B ulletin (MSB) A292 73 2847 , providing additional instructions for an inspection of theEASA AD No.: 20 1 3

- 0 079

TE. CAP.00110

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

- Internet/Intranet. HMU, to be accomplished prior to rotating parts replacement.

For the reasons described a bove, this AD retains the requirements of EASA AD
2011

- 0141, which is superseded, and requires inspection of the HMU and, depending on discrepancies, replacement with serviceable parts and replacement of the HMU rotating components before exceeding newly d efined limits of operating hours.

Effective Date: 05 April 2013

Required Action(s) and Compliance Time(s): Required as indicated, unless accomplished previously:

(1) Before exceeding 400 HMU operating hours since new, or since replacement of LP and HP fuel pumps rotating components in accordance with the instructions of Turboméca MSB A292 73 2847, whichever occurs later, and, thereafter, at intervals not to exceed 400 HMU operating hours, accomplish the following ac t i o ns c on cu rr en tl y in accordance with the instructions of p aragraph 2.B.(1) of Turboméca MSB A292 73 2847 version B:

- I nspect and replace the HMU inter

- pump complete sleeve ( female splines ); and

- I nspect the HMU HP Pump and LP Pump male splines.

Note 1 : a maximum of 25

- hour tolerance can be applied to the defined inspection interval.

(2) If, during any inspection as required by paragraph (1) of this AD, a discrepancy is detected, before next flight, replace the affected HMU with a serviceable HMU in accordance with paragraph 2.B.(1) of Turboméca MSB A292 73 2847 version B.

Note 2 : For the purpose of this AD, a serviceable HMU is a n HMU that has accumulated less than 800 operating hours since new

, or since replacement of LP and HP fuel pumps rotating components in accordance w ith the instructions of Turboméca MSB A292 73 2847, and has accumulated less than 400 operating hours since new or since the last inspection of the rotating components in accordance with the instructions of Turboméca MSB A292 73 2847 version B.

( 3 ) Before exceeding 8 00 HMU operating hours since new, or since replacement of LP and HP fuel pumps rotating components in accordance with the instructions of Turboméca MSB A292 73 2847

, whichever occurs later, and, thereaft er, at intervals not to exceed 8 00 HMU ope rating hours

, replace the rotating components of the HP and LP Pumps including the complete sleeve , or replace the HMU with a serviceable HMU, in accordance with the instructions of paragraph 2.B.(1) of Turboméca MSB A292 73 2847 version B

. ( 4 ) Replacement of parts, accomplished before the effective date of this AD in accordance with the instructions of Turboméca MSB A292 73 2847 version A is acceptable to comply with the initial replacement as required by paragraph ( 3 ) of this AD.

( 5 ) From the e ffective date of this AD, do not install an HMU on an engine, or an engine on a helicopter, unless in compliance with the requirements of this AD.

Ref. Public ations: Turboméca MSB A292 73 2847 version B dated 06 Ma rch 201 3

. 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

.EASA AD No.: 20 1 3

- 0 079

TE. CAP.00110

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

- Internet/Intranet. 2. Based on the required actions and the compliance time, EASA have decided to issue a Final AD with Request for Comments, postponing the public consultation process until after publication

. 3. Enquiries regarding this AD should be referred to the Safety Informa tion Section, Executive 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 ).