COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Fokker F28 Series Aeroplanes AD/F28/68 Fuselage Lap Joint at Stringer 73 12/91 Applicability: All model F28 with serial numbers referenced in the Requirement Document. Requirement: Modify the fuselage lap joint in accordance with the Technical Requirements of RLD AD 90-006 issue 2. Compliance: As specified in the Requirement Document. Background: Investigation following the discovery of cracks in a fuselage lap joint on two aircraft prompted the requirement for a low frequency eddy current inspection, which has now been incorporated into the F28 Structural Integrity Program (S.I.P). The Dutch airworthiness authority has since determined that safety cannot be reliably maintained by inspection, hence this Directive provides for a permanent repair/modification of the affected lap joint.