COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Fokker F27 Series Aeroplanes AD/F27/147 Fuselage Attachment Fittings 10/99 Applicability: Model F27 Mk. 100 through Mk. 700 (except Mk. 500RF), serial numbers 10102 and 10105 through 10582. Requirement: Inspect the wing-to-fuselage fittings in accordance with the Accomplishment Instructions of STORK Fokker Service Bulletin F27/57-77. Note: RLD AD 1999-053 refers. Compliance: Before 7 December 1999, unless already accomplished. This Airworthiness Directive becomes effective on 7 October 1999. Background: The RLD received a report of a cracked wing-to-fuselage attachment fitting. An investigation revealed that the cracking had resulted from stress corrosion cracking. The subject fittings are manufactured from 7079-T6 aluminium, which is known to be sensitive to this type of corrosion.