COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Beechcraft 18 Series Aeroplanes AD/BEECH 18/5 Wing Centre Section Spar Chafing - Inspection NK Applicability: | Model C-18S and AT-11. Requirement: 1. Inspect the lower members of the centre section main wing spar in the landing gear nacelle area for evidence of wear caused by chafing of the cabin heater control housing. 2. To prevent chafing, either use clamps to support the housing or cover it with a 20- in. length of synthetic rubber hose; or FAA AD 48-14-3; or ANO 105.1.4.3.6.5. Compliance: Forthwith. Federal Register of Legislative Instruments F2006B03624