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 participate 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 applicable ADs. Consequently, no person may operate 

an aircraft to which an Airworthiness Directive applies, except in accordance with the requirements of that Airworthiness 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 : 

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 Service 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 & Research 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: 

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