AD/JT8D/41 Compressor Hubs and Disks (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 - JT8D Series

AD/JT8D/41 Compressor Hubs and Disks 12/2005

Applicability:

Pratt & Whitney (PW) JT8D-1, -1A, -1B, - 7, -7A, -7B, -9, -9A, -11, -15, -15A, -17,
-17A, -17R, -17AR, -209, -217, -217A, -217C, and -219 turbofan engines.

Note 1:  These engines are installed on, but not limited to, Boeing 727 and 737 series, and McDonnell Douglas DC-9 series and MD-80 series aeroplanes.

Requirement:

1.    Remove all coating from the disks and hubs identified in Tables 1 and 2 of FAA Airworthiness Directive (AD) 2005-17-16 and visually, dimensionally and non-destructively inspect the parts using the inspection criteria listed in the Accomplishment Instructions portion of Pratt & Whitney Alert Service Bulletin (ASB) No. JT8D A6442 dated 4 April 2003 or later FAA approved revisions.

2.    Do not install any disk or hub listed in Table 1 of FAA AD 2005-17-16 that has zero cycles-in-service since 14 May 2001.

3.    Do not return to service any engine that has a disk or hub listed in Table 1 of FAA AD 2005-17-16 that has zero cycles-in-service since 14 May 2001.

Note 2:  FAA AD 2005-17-16 Amdt 39-14327 refers.

Compliance:

1.    At the next shop visit after the effective date of this AD, but no later than 31 March 2008 for all parts listed in Table 1 of FAA AD 2005-17-16 and at next part accessibility for all parts listed in Table 2 of FAA AD 2005-17-16.

A shop visit is defined as an engine and/or module removal where engine maintenance entails separation of pairs of major engine flanges or the removal of a disk, hub or spool at a maintenance facility, regardless of the scheduled maintenance action or the reason for engine removal.

For the purposes of this AD, accessibility of the HPC rear hub is removing the hub from the engine.

2.    After the effective date of this AD.

3.    After the effective date of this AD.

This Airworthiness Directive becomes effective on 24 November 2005.

Background: This AD results from reports that certain JT8D critical life-limited rotating parts have been returned to service with cracks, corrosion pitting, or dimensions outside of manual limits.  This AD is intended to prevent failure of critical life-limited rotating engine parts, which could result in an uncontained engine failure and damage to the aeroplane.

Jayaprakashan Ambali
Delegate of the Civil Aviation Safety Authority

7 October 2005