{"id":"F2006B05538","name":"AD/PA-24/39 - Fuel Selector Valve - Inspection","slug":"ad-pa-24-39-fuel-selector-valve-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46451,"registerId":"commonwealth-F2006B05538-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-24/39 - Fuel Selector Valve - 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-24 (Comanche) Series Aeroplanes\n\n \n\nAD/PA-24/39 Fuel Selector Valve - Inspection 12/78\n\nApplicability: Model PA-24-400 with S/Nos. 26-2 to 26-148. Document:  Piper SL No. 851, Part A.\n\nNote: Items 1 to 4 only may be performed and certified by pilot.\n\n \n\nCompliance: Within 50 hours time in service after 30 October 1978 and there- after at intervals not exceeding 100 hours time in service.\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\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":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The provided instrument establishes a new inspection requirement limited to specified PA-24-400 serial numbers, with defined timing and a delegation to Piper SL No. 851, Part A for procedure. The text contains no statement or indication that the scope has been changed from a prior instrument."},"complexity_factors":["Narrow applicability by model and serial number range (PA-24-400, S/Nos. 26-2 to 26-148) requires operators to verify serial numbers (Applicability).","Procedural details are not included in the AD text and are delegated to an external document (Piper SL No. 851, Part A), requiring access to and reliance on that service letter (Document).","Division of who may perform and certify work (items 1–4 may be performed and certified by a pilot; other items cannot) creates mixed compliance responsibilities between pilots and maintenance personnel (Note).","Fixed initial and recurrent time-in-service deadlines (within 50 hours after 30 Oct 1978, then every 100 hours) impose scheduling and record-keeping obligations on operators (Compliance).","The AD text does not list the inspection steps or criteria for acceptable condition, increasing dependency on auxiliary material for implementation (Document)."],"plain_english_summary":"This instrument mandates recurring inspections of the fuel selector valve on Piper PA-24-400 (Comanche) aeroplanes with serials 26-2 through 26-148, first within 50 hours TIS after 30 Oct 1978 and thereafter every 100 hours. Procedural detail is in Piper Service Letter No. 851, Part A. Pilots may perform and certify only checklist items 1–4; all other inspection items must be done and signed off by maintenance personnel. It affects owners/operators (costs, scheduling), pilots (limited sign‑off), and maintenance organisations."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive for a specific aircraft type. It has not expanded beyond its original purpose of mandating fuel selector valve inspections for the PA-24-400 series."},"complexity_factors":["Extremely short document (under 200 words)","Only one defined applicability criterion (specific model and serial number range)","Single compliance requirement with straightforward time-in-service intervals","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Simple conditional note regarding pilot-performed items (items 1-4 only)","No nested exceptions or conditional logic chains"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order — issued by Australia's Civil Aviation Safety Authority (CASA) for specific Piper PA-24 Comanche aircraft.\n\n**What it does:**\n- Requires owners and operators of **Piper PA-24-400 model aircraft** (serial numbers 26-2 through 26-148) to **inspect the fuel selector valve** at regular intervals.\n\n**Who it affects:**\n- Owners and operators of these specific Piper Comanche aircraft.\n- Licensed aircraft maintenance engineers (for full compliance).\n- **Pilots** — unusually, this AD allows pilots themselves to perform and certify the first four inspection items (rather than requiring a licensed mechanic).\n\n**When to comply:**\n- First inspection due **within 50 flight hours** after 30 October 1978.\n- **Repeat every 100 flight hours** thereafter.\n\n**Why it matters:**\nFuel selector valve failures can cause fuel starvation — the engine stops getting fuel even when there's plenty in the tank. This has caused accidents. The directive forces proactive inspection to catch valve problems before they become dangerous.\n\n**Key reference:**\n- The inspection follows **Piper Service Letter No. 851, Part A** — manufacturer's official guidance on how to check the valve."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-24-39-fuel-selector-valve-inspection","history":"/api/acts/ad-pa-24-39-fuel-selector-valve-inspection/history","analysis":"/api/acts/ad-pa-24-39-fuel-selector-valve-inspection/analysis","conflicts":"/api/acts/ad-pa-24-39-fuel-selector-valve-inspection/conflicts","importantCases":"/api/acts/ad-pa-24-39-fuel-selector-valve-inspection/important-cases","documents":"/api/acts/ad-pa-24-39-fuel-selector-valve-inspection/documents"}}