COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Schweizer (Hughes) 269 Series Helicopters AD/HU 269/92 Centre Frame Aft Cluster Fittings 6/88 DM Applicability: All models and Serial Numbers listed in the Requirement documents. Requirement: Action in accordance with Schweizer SIN N-217, SIN N-220 and SIN N-221. Compliance: Initial actions to be carried out within 25 hours time in service after 30 March 1988, or prior to 31 May 1988 whichever is sooner. Thereafter, inspect in accordance with the Requirement Documents. Background: Boom support structure cluster fittings that are either misidentified, have stress raisers or are excessively hardened may have been fitted in new production or sold as spares. Failure of a cluster fitting may cause boom separation.