AD/CF6/65 ECU Software Upgrade (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/CF6/65 ECU Software Upgrade 8/2007

Applicability:

General Electric Company (GE) CF6-80C2B1F, -80C2B2F, -80C2B4F, -80C2B5F,
-80C2B6F, -80C2B6FA, -80C2B7F and -80C2B8F turbofan engines with electronic control units (ECUs), installed on Boeing 747 and 767 series aeroplanes.

Requirement:

1.    For Boeing 767 series aeroplanes:

a.     ECU software version 8.2.Q1 must be installed on all affected engines.

b.    At least one of the aeroplane's affected engines must have ECU software version 8.2.Q1 installed.

2.    For Boeing 747 series aeroplanes - ECU software version 8.2.Q1 must be installed on all affected engines.

Software installations specified in Requirements 1and 2 are to be accomplished using paragraphs 3.A. through 3.B.(3)(f)4. of the Accomplishment Instructions of GE Service Bulletin (SB) CF6-80C2 S/B 73-0339, Revision 1, dated
24 April 2007.

3.    Once software version 8.2.Q1 is installed in an ECU, reverting to previous versions of ECU software in that ECU is prohibited.

4.    For a period of 24 months after the effective date of this Directive, once an ECU containing software version 8.2.Q1 is installed on an engine, that ECU can be replaced with an ECU containing a previous software version.  The calendar time specified in Requirements 1 and 2 are not to be exceeded.

5.    After 24 months from the effective date of this Directive, once an ECU containing software version 8.2.Q1 is installed on an engine, if the ECU needs to be replaced for any reason, it must only be replaced by another ECU containing version 8.2.Q1 software.

Definitions

For the purposes of this AD:

Next shop visit of the engine ECU is when the ECU is removed from the engine for overhaul or for maintenance.

Next shop visit of the engine is when the engine is removed from the aeroplane for maintenance in which a major engine flange is disassembled after the effective date of this Directive.  The following engine maintenance actions, either separately or in combination with each other, are not considered a next engine shop visit:

(i)    Removal of the upper high pressure compressor (HPC) stator case solely for airfoil maintenance.

(ii)   Module-level inspection of the HPC rotor stages 3-9 spool.

(iii)   Replacement of stage 5 HPC variable stator vane bushings or lever arms.

(iv)  Removal of the accessory gearbox.

(v)   Replacement of the inlet gearbox polytetrafluoroethylene seal.

Note:  FAA AD 2007-12-07 Amdt 39-15085 refers.

Compliance:

For Requirement 1.a. - At next engine shop visit or ECU shop visit, whichever occurs first, but no later than five years after the effective date of this Directive.

For Requirement 1.b. - Within 24 months after the effective date of this Directive.

For Requirement 2 - At next engine shop visit or ECU shop visit, whichever occurs first, but no later than five years after the effective date of this Directive.

For Requirements 3, 4 and 5 - As of the effective date of this Directive.

This Airworthiness Directive becomes effective on 2 August 2007.

Background:

This United States Federal Aviation Administration has received reports of engine flameout events during flight, including reports of events where all engines simultaneously experienced a flameout or other adverse operation.  This Directive is issued to provide increased margin to flameout, which will minimize the potential of an all-engine flameout event caused by ice accretion and shedding during flight.  Exposure to ice crystals during flight is believed to be associated with these flameout events.

These actions are interim actions due to the on-going investigation, further rulemaking based on the results of the investigation and field experience may be necessary.

David Punshon
Delegate of the Civil Aviation Safety Authority

21 June 2007