AD/PW4000/14 Low Pressure Turbine 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 - PW4000 Series

AD/PW4000/14 Low Pressure Turbine Disks 11/2009

Applicability:

Pratt & Whitney PW4164, PW4168, and PW4168A turbofan engines with certain low pressure turbine (LPT) stage 4 disks, part number (P/N) 51N404, that have a serial number (S/N) listed in Table 1 of this AD, installed.

Note 1:  These engines are installed on, but not limited to, Airbus A330-200 and A330-300 series aeroplanes.

Table 1. - Affected LPT Stage 4 Disks by Serial Number

LPT Stage 4 Disk Serial Nos.
CLDLC01142	CLDLC01151
CLDLC01143	CLDLC01152
CLDLC01144	CLDLC01181
CLDLC01145	CLDLC01182
CLDLC01146	CLDLC01183
CLDLC01148	CLDLC01185
CLDLC01149	CLDLC01186
CLDLC01150	CLDLC01187

Requirement:

1.    Remove from service any LPT stage 4 disk that has an S/N listed in Table 1 of this AD.

2.    Do not install any disk, P/N 51N404, that has an S/N listed in Table 1 of this AD or any disk removed as specified in paragraph (f) of this AD except as allowed by paragraph (h) of this AD.

Note 2:  FAA AD 2007-26-20 Amdt 39-15322 dated 20 December 2007 refers.

Compliance:

For Requirement 1 - At the next piece-part exposure after the effective date of this AD or within 7,500 cycles-since-new, unless the actions have already been done.

For Requirement 2 - After the effective date of this AD.

This Airworthiness Directive becomes effective on 22 October 2009.

Background:

This AD results from a report of improperly manufactured LPT stage 4 disks.  The issuing of this AD is intended to prevent an uncontained engine failure due to low-cycle fatigue, which could result in damage to the aeroplane.

James Coyne
Delegate of the Civil Aviation Safety Authority

2 September 2009