EASA AD No.: 2009-0142

EASA Form 110 Page 1/2 

## EASA AIRWORTHINESS DIRECTIVE

AD No.: 2009 - 0142

Date: 13 July 2009

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 participat e 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 a ccomplishing any applicable ADs. Consequently, no person may opera te an aircraft to which an Airworthiness Directive applies, except in accordance with the requirements of that Airworthiness Direc tive unless otherwise specified by the Agency [EC 2042/2003 Annex I, Part M.A.303] or agreed with the Authority of the State of Regi stry [EC 216/2008, Article 14(4) exemption].


### Type Approval Holder’s Name :
ROLLS-ROYCE plc Type/Model designation(s) :

RB211 Trent 800 Engines

TCDS Number : CAA UK 1051

Foreign AD : Not applicable

Supersedure : None



### ATA 79 Engine – Fuel System, Fuel-to-oil Heat Exchanger (FOHE) – Replacement

Manufacturer(s): Rolls-Royce plc

Applicability: RB211 Trent 895-17, 892-17, 892B-17, 884-17, 884B-17, 877-17and 875-17 engines. These engines are known to be installed on, but not limited to Boeing 777 series aircraft.

Reason: This Airworthiness Directive has been raised following an incident involving dual loss of engine response in the final stages of approach leading to touchdown short of the runway. The phenomenon involved in the loss of engine response has also been seen in flight affecting just one engine.
Post incident analysis and investigation has established that, under certain ambient conditions, ice can accumulate on the walls of the fuel pipes within the aircraft fuel system, which can then be released downstream when fuel flow demand is increased. This released ice can then collect on the FOHE front face and limit fuel flow through the FOHE. This type of icing event was previously unknown and creates ice concentrations in the fuel system beyond those specified in the certification requirements. To mitigate the risk of dual engine FOHE blockage within the Trent 800 engine powered Boeing 777 fleet, which constitutes a potential unsafe condition, this Airworthiness Directive instructs replacement of the FOHE with a modified standard incorporating enhanced anti-icing and de-icing performance.EASA AD No.: 2009-0142

EASA Form 110 Page 2/2 Effective Date: 27 July 2009

Required Action(s) and Compliance Time(s): Within 6 000 flight hours from 10 July 2009 or before 01 January 2011, whichever occurs first:Replace the FOHE with an FOHE modified in accordance with RollsRoyce Alert Service Bulletin RB211-79-AG257, dated 24 June 2009 (published 10 July 2009).

Ref. Publications: Rolls-Royce Alert Servic e Bulletin RB211-79-AG257, dated 24 June 2009 (published 10 July 2009). The use of later approved revisions 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. The required actions and the risk allowance have granted the issuance of a Final AD with Request for Comments, postponing the public consultation process after publication. 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 tec hnical content of the requirements in this AD, please contact: Rolls-Royce plc. PO Box 31, Derby, DE24 8BJ, United Kingdom. Phone: +44 (0) 1332 242424, Fax: +44 (0) 1332 249936. Email: tech.help@rolls-royce.com or download the publication from https://www.aeromanager.com