COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Aerostar (Piper/Ted Smith) 600 and 700 Series Aeroplanes AD/TSA-600/20 Fuel Filler Cap Leakage - Testing 6/79 Applicability: All models. Document: Piper Aerostar SB No. 600-77, Part II only. Compliance: As detailed in the requirements document. Background: Tests carried out on the Aerostar fuel system by the FAA have highlighted the importance of maintaining a proper seal with the wing tank filler caps. Leakage past the cap(s) will reduce the amount of fuel flow to the fuselage tank, causing that tank to be prematurely depleted whilst an appreciable amount of fuel remains in the affected wing tank(s). This condition has resulted in a number of forced landings in the U.S.A.