COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Piper PA-28 Series Aeroplanes AD/PA-28/77 Fuel Line Union Fittings - Inspection 6/79 Applicability: Models: PA28-161 with S/Nos. 28-7816340 to 28-7916410. PA28-181 with S/Nos. 28-7890276 to 28-7990429. PA28-236 with S/Nos. 28-7911001 to 28-7911167. PA28-201T with S/Nos. 28-7921001 to 28-7921028. PA28R-201 with S/Nos. 28R-7837150 to 28R-7837317. PA28R-201T with S/Nos. 28R-7803185 to 28R-7803373. PA28RT-201 with S/Nos. 28R-7918001 to 28R-7918128. PA28RT-201T with S/Nos. 28R-7931001 to 28R-7931187. Document: Piper SB No. 638. Compliance: Within 100 hours time in service from 30 June 1979. Background: A number of fuel line union fittings throughout the aircraft fuel system may have been tightened insufficiently during manufacture and must be retorqued.