COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 747 Series Aeroplanes AD/B747/33 Amdt 2 Wing Trailing Edge Flap Tracks 8/90 Applicability: Model B747 line numbers 1 through 584 except B747SP. Requirement: Action in accordance with Boeing SB747-57A2225 Rev. 4. Note: FAA AD 83-21-02 refers. Compliance: As detailed in the Requirement Document. Background: Water accumulation in the track aft cavity has resulted in corrosion and consequent aft web cracking. Amendment 1 references the latest revision of the Requirement document, which adds terminating action. Amendment 2 clarifies aircraft affected.