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) 593. 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), 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-2008-08R1

Issue Date 

18 March 2008 

Number: CF-2008-08R1 

Subject: Engine Fan Blade Fracture 

Effective: 7 February 2008 

Revision Supersedes Airworthiness Directive (AD) 2008-08 dated 07 February 2008 and is issued 

to correct the SB number in “Note” under paragraph “4.” of the “Corrective Action”. 

Applicability: Pratt & Whitney Canada (P&WC) - PW305A and PW305B engines serial numbers: 

CA0192, CA0195, CA0197, CA0199, CA0200, CA0202, CA0203, CA0204, CA0206, 

CA0207, CA0208, CA0209, CA0210, CA0211, CA0212, CA0213, CA0214, CA0215, 

CA0216, CA0217, CA0218, CA0220, CA0221, CA0223, CA0228, CA0231, CA0232, 

CA0234, CA0235, CA0240, CA0241, CA0243, CA0244, CA0246, CA0247, CA0257, 

CA0259, CA0260, CA0280, CA0300. 

Compliance: Is required as indicated, unless already accomplished. 

Background: There have been two incidents of fan blade dislodgements due to blade fracture on 

relatively hi-time PW305 engines (over 5000 Hrs). The blade dislodgement in both cases 

was contained. However, engine installations sustained considerable collateral damage.

The root cause of fan blade fracture was determined to be the under-minimum material 

condition at the fracture location. 

P&WC has established that the subject under-minimum material condition is limited only 

to fan blades P/N 30B2855-01, manufactured under heat code: MCBWF. Accordingly, 

P&WC on 24 August 2007 issued Alert Service Bulletin (ASB) No. A24588, requiring, on 

priority bases, identification and removal of all such discrepant fan blades from service, in 

accordance with Special Instructions (SI) No.37-2007. ASB No. A24588 was 

subsequently revised (Rev. 2) on 27 November 2007 to include clarification on the 

incorporation of another Service Bulletin (SB) No. 24595, on the same subject.

Considering the potentially hazardous consequence of possible uncontained 

dislodgement of discrepant blade and its impact on aircraft safety, this AD is issued to 

mandate the inspection of the affected engine low-pressure (LP) compressor fan blades 

in accordance with ASB A24588 requirements. 

Corrective 

Actions: 

On all affected engines as specified in the applicability section of this directive,

accomplish in accordance with ASB No. A24588R2 or later revisions approved by the 

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

following: 

1. For engines with more than 5000 hours of operating time; 

Before next flight, inspect low-pressure compressor fan blades and replace any 

blade that is found to be under-minimum material condition. 
No.

 N° CF-2008-08R1 2/2 

Note: One repositioning maintenance flight to facilitate the subject inspection 

may be allowed. 

2. For engines with 5000 or less, but more than 4000 hours of operating time; 

Within 30 hours of operating time from the effective date of this directive, but not 

later than 30 September 2008, inspect low-pressure compressor fan blades and 

replace any blade that is found to be under-minimum material condition. 

3. For engines with 4000 or less, but more than 2500 hours of operating time; 

No later than September 30, 2008, inspect low-pressure compressor fan blades 

and replace any blade that is found to be under-minimum material condition, in 

accordance with one of the following schedules, whichever occurs first: 

 at the next First Stage High Pressure Compressor Rotor inspection (Ref 05-20-00, 

Scheduled Maintenance Checks), or 

 at the next scheduled opportunity where the low-pressure compressor fan is 

removed, (Ref. Hot Section Inspection or Overhaul Shop Visit), or 

 within 300 hrs of operating time from August 24, 2007. 

4. For engines with 2500 or less hours of operating time; 

 Before it accumulates 4000 hours of operating time, but not later than 

30 September 2008, inspect low-pressure compressor fan blades and replace any 

blade that is found to be under-minimum material condition. 

Note: Compliance with earlier versions of ASB No. A24588R2 requirements or 

incorporation of SB No. 24595, prior to the effective date of this directive 

satisfies the corrective action requirements of this directive.

Authorization: For Minister of Transport, Infrastructure and Communities 

Derek Ferguson 

Acting Chief, Continuing Airworthiness 

Contact: Mr. A K Durrani, Continuing Airworthiness, Ottawa, telephone 613-952-5385, facsimile 

613-996-9178 or e-mail durrana@tc.gc.ca or any Transport Canada Centre.