# Transport Transports Canada Canada T P 7245E



# AIRWORTHINESS DIRECTIVE

T he f o l l o w i ng ai rw orthi ness di r e cti v e ( A D ) maybe appl i c abl e to an ai r c r a f t w h i c h our r e cor d s i ndi cate i s r e g i ster ed i n y our na me. AD s ar e i ssued pur suant to Canadian Aviation Regulation ( C A R ) 521 D i v i sion X . Pur s uant to C A R 605.84 and the f u rt her detai l s of C A R St andard 625, A ppendix H , the conti n ui ng ai rw or thi ness of a C anadi an r e g i ster ed ai r c r a f t i s conti n g ent upon compl i ance w i th al l appl i c abl e AD s. Fai l u r e to compl yw i th the r e q u i r ements of an AD ma yi n v a l i date the f l i g ht author i z ati on of the ai r c r a f t. Al ter nati v e means of compl i ance shal l be appl i e d f o r i n accor dance w i th C A R 605.84 and the abov e- r e f e r e nced Standard

. T h i s AD has been i ssued bythe C onti nui ng Ai rw orthi n ess D i v i s i on ( AAR D G )
, N a ti onal Ai r c r a f t C e r t i f i c ati on Br anch, T r ansport C a n ada, Ottaw a , tel ephone 613 952- 4357.

Pur s uant to C A R 202.51 the r e g i ster ed ow ner of a C anadi an ai r c r a f t shal l
, w i thi n sev en day s, noti f ythe M i ni ster i n w r i t i n g of anychang e of hi s or her name or addr ess. T o r e q uest a chang e of addr ess, contact the Civ il Av iat i on Communicat ions Centre (AA RC) at Place de Ville, Ot t a w a , Ont a rio K 1 A 0N 8 , or 1- 800- 305- 2059
, or www. t c
. g c
. c a / c i v i l a v i a t i o n / c o m m u n i c a t i o n s / c e n t r e / a d d r ess.asp

24- 0022 ( 01- 2005) 

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# CF-2010-02 Issue Date 

# 20 January 2010

N u m b e r : C F

- 2 0 1 0

- 0 2
Subject: Fuel Oil Heat Exchanger (FOHE) Fuel Filter By pass Valv e Wear

Effectiv e: 25 January 2010
Applicability : All Pratt and Whitney Canada (P&WC) PW617F-E Engines equipped with FOHE P/N 35C4540-01.
Compliance: Is required as indicated, unless already accomplished
Background: A PW617F-E engine powered twin engined aircraft had recently experienced an uncommanded power reduction on one of its engines. Investigation showed that the Fuel Filter Bypass Valve poppet in the Fuel O il Heat Exchanger (FOHE) on that engine had worn through the housing seat, allowing unfilt ered fuel and debris to contaminate the Fuel Metering Unit (FMU), resulting in fuel flow drop and subsequent power reduction.
P&WC issued an alert Service Bulletin ( SB) A66019 to inspect and replace any discrepant valve with the same type new valv e. The inspection results confirmed that failure of a worn through poppet is dormant and it can affect both engines at the same time that could result in an unsaf e condition on PW617F-E powered aircraft.
On 23 November 2009, P&WC issued an alert SB A66021 that introduced a new Fuel Filter Bypass Valve assembly, with an im proved design poppet to help alleviate the subject poppet wear problem. This Airworthi ness Directive (AD) is issued to mandate replacement of FOHE Fuel Filter Bypa ss Valve on all PW617F-E engines as per P&WC SB A66021 instructions.

Correctiv e Actions: Incorporate P&WC Alert SB A66021, dated 23 November 2009 or later revisions approved by the Chief, Continuing Airworthiness, National Aircraft Certification, Transport Canada, per the following schedule:
1. For engines installed on aircraft w i th more than 25 hours of air time since new : Within 25 hours of air time from the effective date of this AD.
2. For engines installed on aircraft w i th 25 or less hours of air time since new : Within 50 hours of total air time since new.

A u thoriza t ion: F o r Minister of T r ansport, Infrastructure and Communities



# ORIGINAL SIGNED BY
Philip T ang for Derek F e rguson Chief, Continuing Airw orthiness

Conta c t: Mr. A K Durrani, Continuing Airw orthi ness, Ottaw a , telephone 613-952-4357, facsimile 613-996-9178 or e-mail T CAW W EB F eedback@tc.gc.ca or any T r ansport Canada Centre.