COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 747 Series Aeroplanes AD/B747/152 Wings - Front Spar Web Between FSS 628.0 and 675.0 Applicability: B747SP aircraft, Variable Numbers RG001 to RG142 and RG171 to RG222, inclusive. 8/95 Requirement: Perform an ultrasonic, detailed visual and high frequency eddy current inspection of the wing front spar web between wing front spar stations 628 and 675 in accordance with Boeing Service Bulletin (SB) 747-57A2259, Revision 2. Note: FAA AD 90-17-18 refers. Compliance: Initially inspect before further flight after 20 July 1995. Repeat the inspections at intervals not to exceed 1000 flights. Modification in accordance with Boeing SB 747-57A2259, Revision 2, cancels the inspection requirement of this AD. Background: An operator discovered a 790 mm crack in the front spar web of a 747SP aircraft when the aircraft was being refuelled. The fuel was leaking onto the No 3 engine. An undetected crack could lead to structural degradation, a fuel leak and fire.