COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 747 Series Aeroplanes AD/B747/64 Amdt 4 Wing Centre Section - Front Spar Lower Chord Splice Fitting Bolts 9/90 Applicability: All models B747-200 and -300 series aeroplanes with line numbers 1 to 720. Requirement: Action in accordance with FAA AD 90-11-08 Amdt 39-6609, Parts A, B and C. Note 1: Boeing Alert SB 747-57A2247 Rev 3 refers. Note 2: FAA AD 88-11-11 referred to in the previous issue of this CAO Directive. Compliance: For Part A: Unless previously accomplished within the last 350 hours time in service prior to 6 September 1990, within 50 hours time in service after 6 September 1990, and thereafter at intervals not exceeding 400 hours time in service until terminating action is accomplished in accordance with the Requirement Document. For Part B: Unless already accomplished, Prior to 31 July 1993. For Part C: Unless already accomplished, Prior to 31 July 1993. Background: Country of origin AD. There have been overseas reports of fuel leakage into the forward cargo compartment which could result in a fire and substantial damage. Amendment 4 to this Directive references latest FAA AD as the Requirement document. This requires visual inspections as per the previous CAO Directive issue, but, requires terminating actions and inspection of centre wing fuel tank secondary fuel barriers to be accomplished prior to specified date.