EASA AD No.: 20 15

- 0 1 75

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 1 7 5

Date: 2 4 August 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:

TURBOM E CA Type/Model designation(s):

ARRIEL 1 E2 engines

TCDS Number: EASA.E.073

F oreign AD: Not applicable

Supersedure: None



### ATA 7 7 Engine I ndicating

– Tachometer Boxes

– Replacement

Manufacturer(s): Turbomeca

Applicability: ARRIEL 1E2 engines

, all serial numbers

. These engines are known to be installed on, but not limited to, Airbus Helicopter s Deutschland (formerly Eurocopter Deutschland) MBB

- BK117

- C1 and MBB

- BK117

- C2 helicopters

.

Reason: There have been reports of Arriel 1E2 engines having experienced an uncommanded i n

- f light s hut

- down (IFSD) due to an untimely activation of the tachometer box shut

- off system which was activated by the power turbine monitoring function of the tachometer box.
This condition, if not corrected, could potentially lead to further cases of IFSD

, possi bly resulting in a forced landing.
To address this potential unsafe condition , Turbomeca developed modifications (TU369 and TU371) of the tachometer box consisting in the power turbine monitoring function inhibition. In addition, Turbomeca issued Mandatory Service Bulletin (MSB) 292 7 7 084 4 version B to provide instructions for the replacement of the affected tachometer box

. For the reasons described above, t h is AD requires r eplacement of the affected tachometer boxes

.

Effective Date: 0 7 September 2015EASA AD No.: 20 15

- 0 1 75

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. Required A ction(s) and Compliance Time(s) : Required as indicated, unless accomplished previously:

Note 1 : For the purpose of this AD, an affected engine is an engine installed on position #1 (left hand engine position) and is connected to a n affected tachometer box with a Part Number (P/N) and a Serial Number (S/N) listed in Table 1 of this AD

. (1) Within 1 600 flight hours after the effective date of this AD , replace the affected tachometer box (as listed by P/N and S/N in Tabl e 1 of this AD) connected to an affected engine with a serviceable unit , in accordance with the instructions of Turbomeca MSB 292 77 0844 version B

. Note 2 : For the purpose of this AD, a service able tachometer bo x is a unit that is not an affected tachometer box as identified in Table 1 of this AD

.

Table 1

– Affected tachometer boxes

P/N S/N

9580116170

All 9580116260

9580116900

9580117110

9580117550 A ll, except S/N 1500EL (see Note 3 of this AD) and higher

Note 3: P/N 9580117550 with S/N suffix different than “EL” or without suffix is affected by this AD (example: S/N 6091GA, S/N 1713). (2) Replacement of an affected tachometer box

, before the effective date of this AD in accordance with the instructions of Turbomeca MSB 292 77 0844 version A , is acceptable to comply with the requirements of paragraph (1) of this AD.
( 3 ) From the effective date of this AD, it is allowed to install a tachometer box

on an affected engine, provided this unit is a serviceable par t as defined in Note 2 of this AD

.

Ref. Public ations: Turbomeca MSB 292 7 7 084 4 version A dated 04 March 2015 or version B dated 06 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 2 3 July 2015 as PAD 15

- 0 96 for consultation until 20 August 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: Turbomeca, ARRIEL 1 Customer Support, 40220 Tarnos, France, Fax: +33 5 59 74 45 15, or contact your usual or nearest Turboméca technical r epresentative at www.turbomeca

- support.com