1AD/JT8D/29 Amdt 2 - High Pressure Compressor Disc Inspection

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AIRWORTHINESS DIRECTIVE

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For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/JT8D/29 Amdt 1 and issues the following AD under subregulation 39.1 (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.

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Pratt and Whitney Turbine Engines - JT8D Series

AD/JT8D/29

Amdt 2

High Pressure Compressor Disc Inspection 9/2003

TX

Applicability: Pratt & Whitney JT8D-1,1A,-1B,-7,-7A,-7B,-9,-9A,-11,-15,-15A,-17,-17A,-17R, and

17AR series engines.

Requirement: 1. Carry out initial and repetitive inspections of the high pressure compressor (HPC) discs for corrosion pits and cracks, after stripping the protective coating, in accordance with the accomplishment instructions of Pratt and Whitney (PW) Alert Service Bulletin (ASB) JT8D A6431, Revision 1, dated 7 March, 2003; and

2. Replace HPC discs found with corrosion pits or cracks beyond serviceable limits as defined by PW ASB JT8D A6431, Revision 1, dated 7 March, 2003.

Note 1: FAA AD 2003-12-07 Amdt 39-13192 refers and supersedes FAA AD 98-12-

07 and 94-20-01.

Compliance: For Requirement 1: At intervals specified in the compliance section of PW ASB JT8D A6431, Revision 1, dated 7 March, 2003 from the effective date of this Directive.

For Requirement 2: Prior to further flight.

Note 2: Whenever the release date of PW ASB JT8D A6431, Revision 1, dated 7 March, 2003 is referred to in the ASB for calculating compliance intervals, the effective date of this AD applies as specified in the compliance for Requirement 1.

This Amendment becomes effective on 9 July 2003.

Pratt and Whitney Turbine Engines - JT8D Series

AD/JT8D/29 Amdt 2 (continued)

Background: This amendment is prompted by operator reports of cracks found on several JT8D steel HPC discs since the existing AD was published which required removal, inspection and recoating of the HPC discs based on utilisation rates. This amendment requires removal and replacement of protective coating on certain HPC discs, initial and repetitive inspections and removal from service as required. The intention of this AD is to prevent fracture of the HPC discs, which could result in uncontained release of engine fragments, in-flight shutdown and airframe damage.