AD/CF6/77 High Pressure Compressor Rotor (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.

General Electric Turbine Engines - CF6 Series

AD/CF6/77 High Pressure Compressor Rotor 9/2009 DM

Applicability:

General Electric Company (GE) CF6-80C2B5F turbofan engines with a high-pressure compressor rotor (HPCR) stages 11-14 spool/shaft, part number (P/N) 1703M74G03, installed.

Note 1:  These engines are installed on, but not limited to, Boeing 747 series aeroplanes.

Requirement:

1.    Remove any CF6-80C2B5F turbofan engine that has an HPCR stages 11-14 spool/shaft, P/N 1703M74G03, before the spool/shaft meets or exceeds the new, reduced life cycle limit of 19,500 cycles.

2.    Do not install any CF6-80C2B5F turbofan engine that has an HPCR stages 11-14 spool/shaft, P/N 1703M74G03, that meets or exceeds 19,500 cycles.

Note 2:  FAA AD 2009-14-08 dated 25 June 2009 refers.

Compliance:

From the effective date of this AD.

This Airworthiness Directive becomes effective on 5 August 2009.

Background:

This AD results from an internal GE audit that compared the life limited parts certification documentation to the airworthiness limitations section (ALS) of the instructions for continuing airworthiness (ICA).  This AD is intended to prevent HPCR stages 11-14 spool/shaft fatigue cracks caused by exceeding the life limit, which could result in a possible uncontained failure of the HPCR spool/shaft and damage to the aeroplane.

James Coyne
Delegate of the Civil Aviation Safety Authority

2 July 2009