COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 747 Series Aeroplanes AD/B747/158 Fuel Shut-Off Valve Wiring 6/96 Applicability: This Directive is applicable to Model 747-400 series aircraft, with line positions 696 through 1046 inclusive, with the exception of line position 722 and 1035. Requirement: Replace the fuel shut-off valve wire and sleeve in each engine strut conduit with a wire in two non-metallic sleeves in accordance with Boeing Alert Service Bulletin 747-28A2186 dated 19 January 1995. Wire replacements accomplished prior to 23 May 1996, in accordance with Boeing Alert Service Bulletin 747-54A2157 dated 12 January 1995 or Revision 1 dated 3 August 1995, are considered acceptable for compliance with this requirement. Note: FAA AD 96-03-14 Amdt 39-9511 refers. Compliance: Prior to 23 May 1997. Background: The FAA has received reports of additional occurrences of chafing and shorting of the engine fuel shut-off valve wiring since AD 89-14-04 Amdt 39-6246 was issued. The chafing and subsequent shorting of the wiring could result in the flight crews' inability to shut off the fuel supply in the event of an engine fire. Actions required by this Directive are designed to decrease the likelihood of wire chafing occurring.