COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Piper PA-31 Series Aeroplanes AD/PA-31/87 Electroluminescent Panel Inverters 12/79 Applicability: Models PA-31T1 Cheyenne I S/Nos. 31T-7804001 to 31-7904016, and PA-31T1 Cheyenne/Cheyenne II S/Nos. 31T-7400002 to 31T-7920036. Requirement: Action in accordance with Piper SB No. 640. Note: (FAA AD 79-19-09 Amdt. 39-3560 refers). Compliance: Within 100 hours time in service after 31 December 1979. Background: There have been a number of cases overseas where shorting has occurred in the electroluminescent panel inverters resulting in smoke in the cockpit.