Transport Transports 

Canada Canada

 TP 7245E

 

AIRWORTHINESS DIRECTIVE

The following airworthiness directive (AD) may be applicable to an aircraft which our records indicate is registered in your name. ADs are issued pursuant to Canadian Aviation 

Regulation (CAR) 521 Division X. Pursuant to CAR 605.84 and the further details of CAR Standard 625, Appendix H, the continuing airworthiness of a Canadian registered aircraft is contingent upon compliance with all applicable ADs. Failure to comply with the requirements of an AD may invalidate the flight authorization of the aircraft. Alternative means of compliance shall be applied for in accordance with CAR 605.84 and the above-referenced Standard. 

This AD has been issued by the Continuing Airworthiness Division (AARDG), National Aircraft Certification Branch, Transport Canada, Ottawa, telephone 613 952-4357. 

Pursuant to CAR 202.51 the registered owner of a Canadian aircraft shall, within seven days, notify the Minister in writing of any change of his or her name or address. 

To request a change of address, contact the Civil Aviation Communications Centre (AARC) at Place de Ville, Ottawa, Ontario K1A 0N8, or 1-800-305-2059, or www.tc.gc.ca/civilaviation/communications/centre/ address.asp 

24-0022 (01-2005)

1/2 No.

CF-2010-03

Issue Date 

20 January 2010 

Number: CF-2010-03 

Subject: Fuel Oil Heat Exchanger (FOHE) Fuel Filter Bypass Valve Wear 

Effective: 25 January 2010 

Applicability: All Pratt and Whitney Canada (P&WC) PW615F-A Engines equipped with FOHE P/N 35C3778-01 

or P/N 35C3778-02

Compliance: Is required as indicated, unless already accomplished 

Background: A PW617F-E engine powered twin engined aircraft had recently experienced an 

un-commanded power reduction on one of its engines. Investigation showed that Fuel 

Filter Bypass Valve poppet in the Fuel Oil Heat Exchanger (FOHE) on that engine had 

worn through the housing seat, allowing unfiltered fuel and debris to contaminate the 

Fuel Metering Unit (FMU), resulting in fuel flow drop and subsequent power reduction. 

P&WC has confirmed that this is a dormant failure that could result in an unsafe 

condition. 

The PW615F-A engine Fuel Filter Bypass Valve installation is very similar to that of 

PW617F-E, but so far there have been no operational abnormalities reported due to 

subject valve failure on PW615F-A engines. However, evaluation by P&WC has 

confirmed similar dormant failure of worn through poppets of the subject valve on some 

PW615F-A engine installations, which could affect both engines at the same time on an 

aircraft and may result in an unsafe condition. 

P&WC on 9 December 2009, issued an alert Service Bulletin (SB) A63071 that 

introduced a new Fuel Filter Bypass Valve assembly with an improved design poppet, to 

help alleviate the subject poppet wear problem. This Airworthiness Directive (AD) is 

issued to mandate replacement of FOHE Fuel Filter Bypass Valve on all PW615F-A

engines as per the P&WC SB A63071 instructions. 

Corrective 

Actions: 

Incorporate P&WC Alert SB A63071, dated 9 December 2009 or later revisions approved 

by the Chief, Continuing Airworthiness, National Aircraft Certification, Transport Canada, 

per the following schedule: 
No.

 N° CF-2010-03 2/2 

1. For Pre P&WC SB No. A63069 configuration engines installed on aircraft with 

more than 100 hours of total air time since new: 

Within 25 hours of air time from the effective date of this AD. 

2. For Pre P&WC SB No. A63069 configuration engines installed on aircraft with 

100 or less hours of total air time since new: 

Within 150 hours of air time since new. 

3. For Post P&WC SB No. A63069 engines installed on aircraft that has 

accumulated 75 or less hours of air time since SB incorporation: 

Within 100 hours of air time since SB A63069 incorporation. 

4. For Post P&WC SB No. A63069 engines installed on aircraft that has 

accumulated more than 75 hours of air time since SB incorporation: 

Within 25 hours of air time from the effective date of this AD. 

Authorization: For Minister of Transport, Infrastructure and Communities 

ORIGINAL SIGNED BY

Philip Tang for 

Derek Ferguson 

Chief, Continuing Airworthiness 

Contact: Mr. A K Durrani, Continuing Airworthiness, Ottawa, telephone 613-952-4357, facsimile 

613-996-9178 or e-mail CAW WEB Feedback@tc.gc.ca or any Transport Canada 

Centre.