2009-14-12: High Pressure Compressor (HPC)

2009-14-12 Pratt & Whitney Canada Corp: Amendment 39-15962. Docket No. FAA-2009-0046; Directorate Identifier 2008-NE-05-AD. Effective Date (a) This airworthiness directive (AD) becomes effective August 13, 2009. Affected ADs (b) None. (c) This AD applies to Pratt & Whitney Canada Corp. (P&WC) Models PW305A and PW305B turbofan engines with high pressure compressor (HPC) drum rotor assemblies, post P&WC Service Bulletin (SB) PW300-72-24287 but without P&WC SB PW300-72-24376, installed. These engines are installed on, but not limited to, Bombardier Learjet M60 and Hawker Beechcraft 1000 series airplanes. Reason (d) P&WC has determined that the Post-Service Bulletin (SB) PW300-72-24287 High Pressure Compressor (HPC) drum rotor assemblies P/N 30B2478 and 30B2542 on PW305A and 305B engines with single stage coated labyrinth seals, are susceptible to developing significant cracks in the region of the labyrinth seal. We are issuing this AD to detect cracks in the HPC drum rotor assembly, which could lead to an uncontained failure of the drum rotor assembly and damage to the airplane. Actions and Compliance (e) Unless already done, do the following actions. (1) Within 500 flight hours after effective date of this directive, borescope-inspect the interiors of affected HPC rotor assemblies for cracks. If a crack is found, remove the engine before next flight for HPC drum rotor replacement. Pratt & Whitney Maintenance Manual, Chapter 72-00-00, contains guidance on borescope inspection. Credit for Previous Inspections (2) Inspection of affected HPC drum rotor assembly per P&WC SB PW300-72-24462 and or SB PW305 MM 05-20-00 inspection requirements prior to the effective date of this directive satisfies the requirements of paragraph (e)(1) of this AD. (3) Repeat borescope inspection per paragraph (e)(1) of this AD, at intervals not exceeding 1,350 flight cycles. If a crack is found, remove the engine before next flight forHPC rotor drum replacement. Optional Terminating Action (4) Replacement of the affected HPC rotor assembly P/N 30B2478 or 30B2542 with Post-SB PW300-72-24376 assembly P/N 31B6325-01 or later superseding P/N, will constitute terminating action for the inspection requirements of the above paragraphs (e)(1) and (e)(2) of the corrective action requirements of this AD. Other FAA AD Provisions (f) Alternative Methods of Compliance (AMOCs): The Manager, Engine Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Related Information (g) Refer to Canadian Airworthiness Directive CF-2007-25R1, dated February 13, 2008, and P&WC SB PW300-72-24462, dated December 13, 1999, for related information. Contact Pratt & Whitney Canada Corp., 1000 Marie-Victorin, Longueuil, Quebec, Canada J4G 1A1, telephone: (800) 268-8000, for a copy of this service information. (h) Contact Ian Dargin, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: ian.dargin@faa.gov; telephone (781) 238-7178; fax (781) 238-7199, for more information about this AD. Material Incorporated by Reference (i) None.