{"id":"F2006B05632","name":"AD/PA-28/77 - Fuel Line Union Fittings - Inspection","slug":"ad-pa-28-77-fuel-line-union-fittings-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135287,"registerId":"commonwealth-F2006B05632-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-28/77 - Fuel Line Union Fittings - Inspection","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Piper PA-28 Series Aeroplanes\n\n \n\nAD/PA-28/77 Fuel Line Union Fittings - Inspection 6/79\n\nApplicability: Models: PA28-161 with S/Nos. 28-7816340 to 28-7916410.\n\n \n\nPA28-181 with S/Nos. 28-7890276 to 28-7990429.\n\n \n\nPA28-236 with S/Nos. 28-7911001 to 28-7911167.\n\n \n\nPA28-201T 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.\n\nDocument: Piper SB No. 638.\n\n \n\nCompliance: Within 100 hours time in service from 30 June 1979.\n\n \n\nBackground: A number of fuel line union fittings throughout the aircraft fuel system may have been tightened insufficiently during manufacture and must be retorqued.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted Airworthiness Directive addressing a specific manufacturing defect in specific aircraft serial numbers. It has not expanded beyond its original purpose of ensuring fuel system integrity on affected Piper PA-28 aircraft."},"complexity_factors":["Single, discrete safety issue addressed (fuel fittings)","No defined terms section — all language is plain technical English","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Simple conditional structure: if your aircraft serial number is in this list, you must comply","Clear, single compliance deadline (100 hours time in service from specified date)","No exceptions, exemptions, or nested conditions","Short document (approximately 200 words of substantive content)"],"plain_english_summary":"This AD requires owners/operators of certain Piper PA‑28 Cherokees and Arrows to inspect and retorque fuel line union fittings because a manufacturing under-tightening defect can cause fuel leaks. \n\nCompliance is mandatory within 100 flight hours from 30 June 1979; failure to comply renders the aircraft unairworthy due to the increased fire/explosion risk."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive's scope matches its stated purpose: it targets fuel line union fittings on specific PA‑28 models/serial ranges and mandates inspection/retorque to address insufficiently tightened fittings (sources: \"Applicability\", \"Background\", \"Compliance\"). There is no expansion beyond the listed aircraft or the specified corrective action."},"complexity_factors":["Narrow, serial‑numbered applicability across multiple PA‑28 variants (source: \"Applicability\"), which requires operators to check individual airframe records.","Fixed mandatory compliance window (\"Within 100 hours time in service from 30 June 1979\"), creating scheduling pressure for maintenance providers (source: \"Compliance\").","Technical corrective steps are specified by an external document (Piper SB No. 638), so implementers must obtain and follow that service bulletin (source: \"Document\").","The action is a targeted mechanical task (inspect and retorque fuel line union fittings) tied to a specific manufacturing defect (source: \"Background\"), limiting scope but requiring hands‑on maintenance.","Enforcement and cost of compliance fall on aircraft owners/operators and their maintenance organisations (implied by applicability and compliance requirements)."],"plain_english_summary":"This airworthiness directive requires owners/operators of specified Piper PA‑28 aeroplanes (listed by model and serial‑number ranges) to inspect and retorque fuel line union fittings within 100 hours time‑in‑service from 30 June 1979, using the procedure in Piper Service Bulletin No. 638. The measure responds to a manufacturing issue: some fittings may have been insufficiently tightened during production, so the inspection/retorque is intended to reduce the risk of fuel leakage."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-28-77-fuel-line-union-fittings-inspection","history":"/api/acts/ad-pa-28-77-fuel-line-union-fittings-inspection/history","analysis":"/api/acts/ad-pa-28-77-fuel-line-union-fittings-inspection/analysis","conflicts":"/api/acts/ad-pa-28-77-fuel-line-union-fittings-inspection/conflicts","importantCases":"/api/acts/ad-pa-28-77-fuel-line-union-fittings-inspection/important-cases","documents":"/api/acts/ad-pa-28-77-fuel-line-union-fittings-inspection/documents"}}