AD/PW4000/17 - Turbine Exhaust Case (Cth)

AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Pratt and Whitney Turbine Engines - PW4000 Series AD/PW4000/17 Turbine Exhaust Case 19/2010

Applicability: Pratt and Whitney PW4000 engines as specified by models in FAA AD 2003-26-09. Requirement: Unless already accomplished perform the initial inspections in accordance with the technical requirements of FAA AD 2003-26-09.

Repeat the inspections in accordance with the technical requirements of FAA AD 2003-26-09.

Later revisions to PW ASB PW4G-112-A72-257, Revision 1, dated 22 August 2003, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2003-26-09, are considered acceptable for compliance with the equivalent Requirements of this AD. Compliance: As specified in the Requirement Document with a revised effective date of 20 September 2010. This Airworthiness Directive becomes effective on 20 September 2010. Background: There have been of reports of engine high pressure turbine (HPT) assembly hardware being damaged as a result of thermal distress from oil igniting after leaking from the No. 3 bearing compartment. This AD is issued to prevent thermal distressed HPT assembly hardware from remaining in service, which could result in a cracked HPT stage 1 disc and HPT stage 1-2 air seal and an uncontained engine failure.