COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Boeing 747 Series Aeroplanes
AD/B747/141 Pylon - Inboard and Outboard Strut Forward Lower Spar
5/95
B747 L/N 001 - 510 powered by JT9D-3 or -7 series engines, excluding JT9D-70 engines.
Perform a detailed visual inspection of the Inboard and Outboard Strut Forward Lower Spar Chords, Stiffeners and Web to detect cracks and loose fasteners. Inspect in accordance with Boeing Service Bulletin 747-54-2160.
FAA AD 94-17-17 refers.
Initially inspect before 2 February 1996 or before exceeding 6000 landings, whichever is the later.
Aircraft that have accumulated between 6000 and 15000 landings shall be inspected before 2 October 1995.
Aircraft which have accumulated more than 15000 landings shall be inspected before 2 July 1995.
Reinspect at intervals not to exceed 2000 landings or 8000 hours time in service, whichever occurs first.
There have been five reports of cracks in the subject web. In addition it is suspected that a web crack may have contributed to a recent engine separation.