Document ID: chunk:federal_register_of_legislation:F2008L00551:body:0:p2
Version: federal_register_of_legislation:F2008L00551
Segment Type: other
Provision Reference: 
Character Range: 2970–4778

Shop Visit), or

                  -          within 300 hours of operating time from 24 August 2007.

                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.

                2. Before further flight after the effective date of this AD.
             This Airworthiness Directive becomes effective on 22 February 2008.
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.

David Punshon
Delegate of the Civil Aviation Safety Authority

19 February 2008