AD/B747/131 Amdt 1 Flap Control Unit Wiring Change (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/B747/131 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.

Boeing 747 Series Aeroplanes

AD/B747/131 Amdt 1 Flap Control Unit Wiring Change 8/2009

Applicability:	Model 747-400 series aeroplanes having line numbers 696 through 1036 inclusive.
Requirement:	1.    For aeroplanes having line numbers 696 through 1019 inclusive and 1021 through 1026 inclusive, unless previously accomplished in accordance with AD/B747/131 (FAA AD 94-14-21), revise the input wiring for the flap control unit (FCU) in accordance with Boeing Service Bulletin SB 747-27A2346, Revision 1, dated 19 May 1994, or Revision 2, dated 12 January 1995.
2.    For aeroplanes having line numbers 1020, and 1027 through 1036 inclusive, unless previously accomplished, revise the input wiring for the FCU in accordance with SB 747-27A2346, Revision 2.
3.    For aeroplanes having line numbers 696 through 1036 inclusive, unless previously accomplished, perform the additional systems test for the wiring of the trailing edge flap in accordance with SB 747-27A2346, Revision 2.
Later revisions of the SB 747-27A2346, Revision 2, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 95-12-27 are considered acceptable for compliance with the equivalent Requirements of this Amendment.
Note:  FAA AD 95-12-27 Amdt 39-9280 refers.
Compliance:	For Requirements 1 through 3 - Within 60 days after the effective date of this Amendment.
This Amendment becomes effective on 30 July 2009.
Background:	The FAA received reports of disconnection of the Landing Gear Module electrical connectors, this disconnection can result in the loss of the primary, secondary and alternate control of the flaps.  Compliance with the initial issue of this Directive decreased the likelihood of an all-up-flaps landing due to the loss of control of all flap operations.

Subsequently the FAA received a report indicating that a wiring error was not detected by the system test required by the existing Directive.  This Amendment requires a new systems test for the wiring of the trailing edge flap and also expands the applicability of the existing Directive to include additional aeroplanes.

The original issue of this Directive became effective on 15 September 1994.

James Coyne
Delegate of the Civil Aviation Safety Authority

16 June 2009