{"id":"F2006B05792","name":"AD/PA-31/86 Amdt 2 - Scott Fuel Selector Valve and Cable","slug":"ad-pa-31-86-amdt-2-scott-fuel-selector-valve-and-cable","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135694,"registerId":"commonwealth-F2006B05792-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-31/86 Amdt 2 - Scott Fuel Selector Valve and Cable","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nPiper PA-31 Series Aeroplanes\n\nAD/PA-31/86\n\nAmdt 2\n\n  \nScott Fuel Selector Valve and Cable 9/87\n\nApplicability: Models PA-31, PA-31-300 and PA-31-325, with S/Nos. 31-2 to 31-7912023; PA-31- 350 with S/Nos. 31-5001 to 31-7305052 and PA-31P with S/Nos. 31P-3 to 31P- 7730004, if fitted with Scott fuel selector valves.\n\nRequirement: 1. Service the fuel selector valve in accordance with Section B of Piper SB No.\n\n648A.\n\n    2. Replace the fuel selector valve “O” rings in accordance with Section C of Piper SB No. 648A.\n\n    3. Inspect the fuel selector valve control cables in accordance with Part II of Piper SB No. 648A, unless modified in accordance with Part III of Piper SB No. 648A.\n\nNote: FAA AD 80-18-10, Amendment 39-3903 also refers to this subject.\n\nCompliance: 1. Within 100 hours time in service after 31 January 1981 and thereafter at intervals not exceeding 100 hours time in service.\n\n    2. At intervals not exceeding 1000 hours time in service.\n\n    3. Within 100 hours time in service after 31 January 1981 and thereafter at intervals not exceeding 100 hours time in service.\n\nBackground: The Scott fuel selector valve may exhibit sticking or binding of the spool “O” rings which, if allowed to continue, could lead to inadvertent fuel shutoff. As a consequence of a binding selector the valve control cables may fail due to fatigue at the swivel fittings. This Amendment is raised to incorporate a Revision of the Requirement document which adds models affected and announces the availability of an improved fuel selector valve control cable.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is Amendment 2 to an existing AD from 1986. The amendment explicitly states its limited purpose: adding newly affected aircraft models and announcing availability of improved control cables. The scope remains tightly focused on the original safety issue (fuel selector valve failures) without expansion into unrelated systems."},"complexity_factors":["Short, single-purpose document (1 page)","Only 3 defined applicability criteria (aircraft models and serial numbers)","3 numbered requirements with clear cross-references to Piper Service Bulletin 648A","Simple temporal compliance structure (flight hours-based intervals)","One conditional exception (requirement 3 has an 'unless' clause for modified cables)","No nested definitions or recursive cross-referencing"],"plain_english_summary":"This Airworthiness Directive mandates periodic servicing and parts replacement for Scott fuel selector valves and inspections or upgrades of control cables on certain Piper PA‑31 series aircraft to prevent valve sticking, inadvertent fuel shutoff, and cable failure. It applies to owners and operators of affected Piper aircraft registered in Australia; non‑compliance grounds the aircraft and is unlawful."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This Amendment expanded the list of affected models/serial numbers and announces availability of an improved fuel selector valve control cable, thereby broadening applicability and adding a modification option that can alter inspection requirements (Background)."},"complexity_factors":["Multiple affected models and serial‑number ranges increase applicability complexity (Applicability).","Cross‑reference to Piper Service Bulletin No. 648A with separate Sections/Parts (Requirement: Sections B, C, Part II/III) requires operators to consult external technical documents.","Different recurring compliance intervals (100 hours for servicing/inspection; 1000 hours for O‑ring replacement) create scheduling complexity (Compliance).","Optional modification (Part III) that changes inspection obligations introduces conditional compliance paths.","Safety‑critical failure mode (selector sticking causing inadvertent fuel shutoff and cable fatigue) raises enforcement and risk‑management demands (Background).","Reference to an FAA AD adds an international compliance touchpoint (Note).","Responsibility and cost fall on aircraft owners/operators to perform mandated maintenance and replacements (Requirement/Compliance)."],"plain_english_summary":"This Airworthiness Directive requires operators of specified Piper PA‑31 series aircraft fitted with Scott fuel selector valves to follow Piper Service Bulletin No. 648A to service the valve, replace spool “O” rings and inspect (or, if modified, reduce) control‑cable inspections at set intervals to prevent selector sticking and cable fatigue that can shut off fuel. Aircraft operators pay for and schedule the maintenance; the regulator enforces compliance. The AD also recognises an improved cable modification that, if installed, alters the inspection requirement."},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-31-86-amdt-2-scott-fuel-selector-valve-and-cable","history":"/api/acts/ad-pa-31-86-amdt-2-scott-fuel-selector-valve-and-cable/history","analysis":"/api/acts/ad-pa-31-86-amdt-2-scott-fuel-selector-valve-and-cable/analysis","conflicts":"/api/acts/ad-pa-31-86-amdt-2-scott-fuel-selector-valve-and-cable/conflicts","importantCases":"/api/acts/ad-pa-31-86-amdt-2-scott-fuel-selector-valve-and-cable/important-cases","documents":"/api/acts/ad-pa-31-86-amdt-2-scott-fuel-selector-valve-and-cable/documents"}}