AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section. DHC-6 (Twin Otter) Series Aeroplanes AD/DHC-6/76 Floatplane Float to Chassis Bolts 6/2008 Applicability: Model DHC-6 Floatplanes, all Series, equipped with Canadian Aircraft Products Model 12000A or 12000B Floats installed prior to Float Serial No. 71. Requirement: Action in accordance with de Havilland Service Bulletin 6/296 Revision A, dated 11 May 1973, or later Transport Canada approved revision. The inspections required by this Directive may be discontinued upon incorporation of either de Havilland Modification 6/1464 described in de Havilland Service Bulletin 6/296 Revision A, or equivalent approved modification. Note: Transport Canada AD CF-73-11 refers. Compliance: At intervals not to exceed 75 flight hours; until modified. This Airworthiness Directive becomes effective on 5 June 2008. Background: The actions required by this Directive are intended to prevent loosening and subsequent pull-out failure of certain float to chassis bolts. David Villiers Delegate of the Civil Aviation Safety Authority 23 April 2008