COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Fokker F27 Series Aeroplanes AD/F27/128 Outer Flap Lower Skin and Rib 2/92 Applicability: All model F27, all serial numbers. Requirement: Inspect the outer flap lower skin and rib in accordance with the technical requirements of Fokker SB F27/57-67. Note: RLD AD 91-122 refers. Compliance: As specified in the Requirement document with a revised effective date of 3 February 1992 (a four month extension). Background: Country of origin AD. Some operators are reported to have found cracks at various locations in the lower skin and rib at STA.580 of the outer flaps. As these cracks are likely to exist on other aircraft of the same type, this AD requires inspection of the affected areas and provides for a repair if necessary.