EASA AD No : 2008-0133

EASA Form 110 Page 1/2 

## EASA AIRWORTHINESS DIRECTIVE

AD No.: 2008-0133

Date: 17 July 2008

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 parti cipate in the activities of EASA under Article 66 of that Regulation.

This AD is issued in accordance with EC 1702/2003, Part 21A .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 a pplicable ADs. Consequently, no person may operate an aircraft to which an Airworthiness Directive applies, exc ept in accordance with the requirements of that Airworthine ss Directive unless otherwise specified by the Agency [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) exemption].



### Type Approval Holder’s Name :
TURBOMÉCA Type/Model designation(s) :

ARRIUS 1A turbo-shaft engine

TCDS Number : France No. M16

Foreign AD : Not applicable

Supersedure : None



### ATA 73 Engine Fuel & Control - Balancing Piston Life Limit - Reduction

Manufacturer(s): Turboméca

Applicability: ARRIUS 1A turbo-s haft engines, all serial numbers.

These engines are known to be installed on, but not limited to, Eurocopter AS355N helicopters.

Reason: Cycle life limit value for ARRIUS 1A balancing piston Part Number (P/N) 0 319 20 152 0, initially set at 40 000 cycles, has been reduced to 16 000 cycles, following the discovery of a calculation error during a recent review of the ARRI US 1 engine family files.

As of the publication date of this Ai rworthiness Directive, no ARRIUS 1A engines in service are fitted with a balancing piston that has logged more than 16 000 cycles, and the outlook for the consumption of cycles on the ARRIUS 1A fleet indicates that no balancing pistons w ill exceed this new limit for a few years’ time.

Moreover, this new cycle life limit value for the balancing piston has been incorporated end of 2007 in ARRIUS 1A Maintenance documentation.

Failure to comply with the new life limits provided in the Airworthiness Limitations Section of ARRIUS 1A Maintenance documentation could potentially result in an engine in-fli ght-shutdown and the release of high energy debris.EASA AD No : 2008-0133

EASA Form 110 Page 2/2 Effective Date: 31 July 2008

Required action(s) and Compliance Time(s): Required as indicated, unless accomplished previously:
Before 31 December 2008, modify the cycle life limit value of the balancing piston in the engine log book in accordance with the instructions of Turboméca Mandatory Service Bulletin N° 319 72 0811 and update accordingly the approved operator’s maintenance programme.

Ref. Publications: Turboméca Service Bulletin N° 319 72 0811 original issue
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 09 July 2008 as PAD 08-067 for consultation until 11 June 2008. No comments were received during the consultation period.
3. Enquiries regarding this AD should be referred to the Airworthiness Directives, Safety Management & Re search Section, Certification Directorate, EASA. E-mail ADs@easa.europa.eu

. 4. For any question concerning the te chnical content of the requirements in this AD, please contact: Turboméca, S.A., ARRIUS Cu stomer Support, 40220 TARNOS, FRANCE. Fax: +33 5 59 74 45 15, or contact your nearest technical representative at www.turbomeca-support.com