AD/CF6/74 Amdt 1 High Pressure Compressor Spool Shaft Stage 14 Disc (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/CF6/74 and issues the following 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/CF6/74 Amdt 1 High Pressure Compressor
Spool Shaft Stage 14 Disc 24/2011

Applicability:

General Electric Company (GE) CF6-80C2 and CF6-80E1 series turbofan engines with high-pressure compressor rotor (HPCR) spool shaft stage 14 disks, part number (P/N) 1703M49G02, 1703M49G03, or 1509M71G10 installed.

Note 1:  These engines are installed on, but not limited to, Airbus A300-600R/F, A310-200/300, and A330-200/300, and Boeing 747-200B/300/400/400D/400F,
767-200/300/400F/400ER, and MD-11 aeroplanes.

Requirement:

Using the following Alert Service Bulletin (ASB) instructions, perform a one-time ECI of the HPCR spool shaft stage 14 disk web for crack indications, and remove from service those parts found to be cracked.

Use paragraphs 3.B.(1) through 3.B.(5) of the Accomplishment Instructions of GE ASB No. CF6-80C2 S/B 72-A1122, Revision 1, dated 19 June 2006, to ECI the
CF6-80C2 series engine HPCR spool shaft stage 14 disk web at the module level.

Use paragraph 3.C.(1) of the Accomplishment Instructions of GE ASB No.
CF6-80C2 S/B 72-A1122, Revision 1, dated 19 June 2006, to ECI the CF6-80C2 series engine HPCR spool shaft stage 14 disk web at the piece-part level.

Use paragraphs 3.B.(1) through 3.B.(5) of the Accomplishment Instructions of GE ASB No. CF6-80E1 S/B 72-A0258, Revision 1, dated 15 June 2006, to ECI the
CF6-80E1 series engine HPCR spool shaft stage 14 disk web at the module level.

Use paragraph 3.C.(1) of the Accomplishment Instructions of GE ASB No. CF6-80E1 S/B 72-A0258, Revision 1, dated 15 June 2006, to ECI the HPCR spool shaft stage 14 disk web at the piece-part level.

Previous Credit

Performance of a one-time ECI of the HPCR spool shaft stage 14 disk web for crack indications, using the procedures defined in the following service documents before the original effective date of this AD, satisfies the compliance requirements specified in this AD:

a)    GE ASB No. CF6 80C2 S/B 72-A1122, dated 19 January 2004, for
CF6-80C2 series engines.

b)    GE ASB No. CF6 80E1 S/B 72-A0258, dated 19 January 2004, for CF6-80E1 series engines.

Later revisions to GE ASB No. CF6-80C2 S/B 72-A1122, Revision 1, dated 19 June 2006 or GE ASB No. CF6-80E1 S/B 72-A0258, Revision 1, dated 15 June 2006, approved by the United States Federal Aviation Administration (FAA) as an Alternative Method of Compliance (AMOC) to FAA 2009-07-03 Amdt 39-15862, are considered acceptable for compliance with the equivalent Requirements of this AD.

Note 2:  FAA AD 2009-07-03 Amdt 39-15862 dated 18 March 2009 refers.

Compliance:

At the next engine shop visit where the separation of a major engine flange will occur after the effective date of this AD, unless the actions have already been done.

For the purpose of this AD, introduction of an engine into a shop solely for the following maintenance actions is not considered an engine shop visit:

(1)   Removal of a compressor case for airfoil or variable stator vane bushing maintenance.

(2)   Removal or replacement of the stage 1 fan disk.

(3)   Replacement of the turbine rear frame.

(4)   Removal or replacement of the accessory and/or transfer gearbox.

(5)   Removal or replacement of the fan forward case.

(6)   Any combination of the maintenance actions listed above.

This Amendment becomes effective on 1 December 2011.

Background:

This AD results from reports of 12 cracked HPCR spool shaft stage 14 disk webs discovered to date.  The issuing of this AD is intended to prevent cracks from propagating to an uncontained failure of the disk and damage to the aeroplane.

Amendment 1 notates the acceptability of an FAA Approved AMOC for compliance with the equivalent requirements of this AD.

The original issue of this Directive became effective on 4 June 2009.

Mike Higgins
Delegate of the Civil Aviation Safety Authority

29 November 2011