COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Fokker F28 Series Aeroplanes AD/F28/64 Cold-Bonded Lap Joint Rivets 5/91 Applicability: Model F28 with serial numbers 11003 through 11013, and 11991 through 11992. Requirement: Action in accordance with the technical requirements of RLD AD 90-126. Note: Fokker SB F28/53-109 refers. Compliance: As specified in the Requirement document but with a revised effectivity date of 16 May 1991 for Australian registered aircraft. Background: Disbonding of cold-bonded longitudinal fuselage lap joints has been detected on several aircraft. Prolonged operation with large areas of disbonded lapjoints will result in fatigue cracking of rivet holes. To ensure sufficient fatigue life, identified critical rivets are replaced by protruding head type rivets.