AD/CF6/76 High Pressure Turbine Stage 1 Rotor Discs (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/CF6/76 High Pressure Turbine Stage 1 Rotor Discs 6/2009

Applicability:

General Electric Company (GE) CF6-80A series turbofan engines with any of the following stage 1 high-pressure turbine (HPT) rotor disc part numbers (P/Ns), installed:

(a)   1380M69G01; 1380M69G02; 1380M69G04; 1380M69G05; or 1380M69G06; or

(b)   9234M67G12; 9234M67G13; 9234M67G14; 9234M67G15; or 9234M67G16; or

(c)   9362M58G04; or

(d)   9367M45G01; 9367M45G03; 9367M45G05; 9367M45G06; 9367M45G07; or 9367M45G08.

Note 1:  These CF6-80A series turbofan engines are installed on, but not limited to, Airbus A310-200 series and Boeing 767-200 and -300 series aeroplanes.

Requirement:

1.    Remove from service HPT stage 1 rotor discs identified in the applicability section of this AD.

2.    Do not install any of the HPT stage 1 rotor discs, identified in the applicability section of this AD into any engine.

Note 2:  FAA AD 2009-08-06 Amdt 39-15879 dated 6 April 2009 refers.

Compliance:

For Requirement 1 - Within 30 days after the effective date of this AD, unless the actions have already been done.

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

This Airworthiness Directive becomes effective on 4 June 2009.

Background: The discs detailed in this AD are susceptible to cracks developing at the aft chamfer of the blade dovetail slots.  The actions detailed in this AD are to prevent cracks developing at the aft chamfer of the blade dovetail slots that could propagate to a failure of the disc and cause an uncontained engine failure and damage to the aeroplane.

James Coyne
Delegate of the Civil Aviation Safety Authority

17 April 2009