COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Beechcraft 60 (Duke) Series Aeroplanes AD/BEECH 60/44 Cabin Heat Electrical Wiring 4/99 DM Applicability: Beech Model 60 aeroplanes with serial numbers P-159 and P-166 up to and including P-596. Requirement: Modify the cabin heat control electrical wiring in accordance with the Accomplishment Instructions of Raytheon Mandatory Service Bulletin SB 24-3097 issued December 1998. Note: FAA AD 99-03-11 Amdt 39-11024 refers. Compliance: Within 25 hours' time in service after the effective date of this Directive. This Airworthiness Directive becomes effective on 3 March 1999. Background: The FAA has received a report of an incident where the cabin heater electrical control circuits overheated in flight and caused the cabin heater to shut down. This Directive requires modifications to the cabin heater wiring which are designed to prevent the circuit overheating, which could result in smoke and/or fire.