COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES DHC-6 (Twin Otter) Series Aeroplanes AD/DHC-6/54 Amdt 2 Side Folding Cabin Utility Seats - Inspection and Modification 5/85 Applicability: All model DHC-6 Aircraft fitted with side folding cabin utility seats. Document: De Havilland of Canada S.B. No. 6/447 Rev. A. Note: Transport Canada AD CF-83-25 R1 refers. Compliance: 1. Unless already accomplished, inspect within 10 hours time in service after 27 March 1984 in accordance with requirements detailed in the requirement document. 2. Repeat inspections in accordance with requirements detailed in the requirement document at intervals not exceeding 50 hours time in service until modification No. 6/1828 is incorporated on all side folding utility seats. 3. After incorporation of modification No. 6/1828 inspect in accordance with the De Havilland Inspection Requirement Manual Revision 6, chapter 25, Item 5. Background: Service experience has shown that the front legs of the cabin utility seats can be become disengaged from the keyhole slots in the floor, creating a hazard to the occupants. This directive is amended to reflect Revision 1 of the Canadian AD which requires compliance with the DHC6 Inspection Requirement Manual after modification.