AD/B767/39 Amdt 1 Hydraulic System Component/Electrical Wiring Chafing Engine Struts (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/B767/39 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 767 Series Aeroplanes

AD/B767/39 Amdt 1 Hydraulic System Component/Electrical Wiring Chafing Engine Struts 12/2005

Applicability:	Boeing 767 series aircraft listed in Boeing Alert Service Bulletin (ASB) 767-29A0054 dated 26 March 1990 together with aeroplanes line number 308 and 311.
Requirement:	If not previously accomplished in accordance with the original issue of this Directive, inspect the wiring in the aft fairing area of the engine struts in accordance with ASB 767-29A0054, 767-29A0054 Revision 1 dated 24 May 1990 or 767-29A0054 Revision 2 dated 8 November 1990, to ensure sufficient clearance exists between the wire bundles and the hydraulic components in this area.
Note:  FAA AD 91-02-03 Amdt 39-6853 refers.
Compliance:	Within 500 hours time in service after the effective date of this Amendment.
This Amendment becomes effective on 24 November 2005.
Background:	There have been nine reports of insufficient separation between the wiring bundles and hydraulic components in this area, and on three of these aircraft the AC motor pump feeder cable was chafed through.  This had resulted in arcing, which on two of these aircraft had burned holes in the pump case drain tube, and on one of these aircraft had burned a hole in the boss on the hydraulic reservoir.  The result of these holes was leakage of hydraulic fluid and loss of the affected hydraulic system.  Although no fire occurred in any of these cases, ignition of the hydraulic fluid was possible with potentially disastrous consequences.
This amendment results from a request under CASR 39.006 from industry to review the original Directive.  The amendment corrects the applicability statement and includes an additional service bulletin revision as an alternate method of compliance, together with a reference to the superseding FAA Airworthiness Directive.
The original issue of this Directive became effective on 6 September 1990.

Jayaprakashan Ambali
Delegate of the Civil Aviation Safety Authority

13 October 2005