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-31/67 Goodyear Fuel Cells - Inspection 6/78 Applicability: Models: PA-31 and PA-31-300 with S/Nos. 31-1 and on; PA-31-350 with S/Nos. 31- 5001 and on; PA-31P with S/Nos. 31-P and on; PA-31T with S/Nos. 31T-7400002 and on; fitted with Goodyear BTC-39 fuel cells. Document: Piper SB No. 591. Compliance: Within 100 hours time in service after 30 June 1978 and annually thereafter as detailed in Piper SB No. 591.