COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES SAAB SF340 Series Aeroplanes AD/SF340/15 Delamination of Composite Structure 5/89 DM Applicability: Model SF340A S/No 103 to 139 inclusive. Requirement: Action in accordance with SAAB SB SF340-51-006. Note: Swedish AD 1-031 refers. Compliance: At the next A-check/E-check after 29 March 1989 and thereafter at each heavy landing or flight in turbulence per AMM 05-50-00 until replaced or repaired in accordance with a Scheme approved by the Authority. Background: The manufacturer has found that due to production difficulties and insufficient documentation some composite parts may be delaminated. Water intrusion may cause further delamination and affect structural integrity.