AD/CF6/75 High Pressure Turbine Rotor Stage 1 Disc (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/CF6/75 High Pressure Turbine Rotor Stage 1 Disc 6/2009

Applicability:

General Electric Co. (GE) CF6-80A, CF6-80A1, CF6-80A2, and CF6-80A3 turbofan engines with a high-pressure turbine rotor (HPTR) stage 1 disc, part number (P/N) 9367M45G06, installed.

Note 1:  These engines are installed on, but not limited to, Airbus A310 series and Boeing 767 series aeroplanes.

Requirement:

Remove HPTR stage 1 discs, P/N 9367M45G06, from service before exceeding the new, reduced life limit of 2,075 cycles-since-new.

Note 2:  FAA AD 2009-07-10 Amdt 39-15869 dated 25 March 2009 refers.

Compliance:

From the effective date of this AD, unless previously accomplished.

This Airworthiness Directive becomes effective on 4 June 2009.

Background:

This AD results from an error by GE that incorrectly cited a cyclic life of 12,600 CSN in the Airworthiness Limitations Section (ALS) of the Instructions for Continued Airworthiness (ICA) for the HPTR stage 1 disc, P/N 9367M45G06.  The issuing of this AD is to prevent the HPTR stage 1 disk from exceeding its part life, which could cause fatigue cracks to start and grow.  These cracks could result in a possible uncontained disc failure and damage to the aeroplane.

James Coyne
Delegate of the Civil Aviation Safety Authority

17 April 2009