{"id":"F2006B05553","name":"AD/PA-25/15 - Main Landing Gear Shock Strut - Inspection and Modification","slug":"ad-pa-25-15-main-landing-gear-shock-strut-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46519,"registerId":"commonwealth-F2006B05553-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-25/15 - Main Landing Gear Shock Strut - Inspection and Modification","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-25 (Pawnee) Series Aeroplanes\n\n \n\nAD/PA-25/15 Main Landing Gear Shock Strut - Inspection\n\nand Modification\n\n\n8/63\n\n \n\nApplicability: Model PA-25-235 and variants of that model with S/Nos. 25-2000 to 25-2591. Document:               1. Piper SB No. 217; or\n\n2. FAA AD 63-17-5.\n\n \n\nCompliance: Inspect at each daily inspection until modified to SB 217.\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":3,"scope_assessment":{"changed":false,"description":"The source text does not specify any change from an earlier or original instrument. It sets a clear, limited scope: specified PA-25-235 serial numbers must be inspected at each daily inspection until modified per Piper SB No. 217 or FAA AD 63-17-5. No alteration of that scope is indicated in the provided text."},"complexity_factors":["Very narrow applicability by model and specific serial-number range (reduces scope complexity). (Applicability)","Single, simple recurring action required: daily inspection until modification (straightforward compliance step). (Compliance)","Dependence on external technical documents (Piper SB No. 217 and FAA AD 63-17-5) introduces procedural and sourcing complexity. (Document)","Outcome of compliance is binary (inspect until modified; modification removes inspection requirement), which simplifies long-run compliance tracking. (Compliance)","Potential practical complexity in obtaining parts, technical data or qualified maintenance for the SB modification (imposes operational and supply-chain considerations). (Document)"],"plain_english_summary":"This AD requires owners/operators of Piper PA-25-235 aircraft (S/N 25-2000–25-2591) to inspect the main landing-gear shock strut at every daily inspection until the aircraft is modified per Piper SB No. 217 or FAA AD 63-17-5. It affects affected owners, operators and maintenance providers, imposing recurring inspection costs that end only after the one‑time SB 217 modification is performed."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in a limited aircraft population. It has not expanded beyond its original purpose of ensuring main landing gear shock strut integrity in early-model PA-25 aircraft."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 defined applicability criteria (model and serial number range)","Simple binary compliance structure: inspect daily OR modify per SB 217","No nested exceptions, conditional logic, or cross-references to other legislation","References only 2 external technical documents (Piper SB 217 and FAA AD 63-17-5)","Single operational requirement with clear cessation condition (inspection stops once modification complete)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It applies to specific **Piper PA-25 Pawnee aircraft** (agricultural spray planes) with serial numbers between 25-2000 and 25-2591.\n\n**What it requires:**\n- **Inspection:** Owners and operators must check the main landing gear shock strut (the shock-absorbing component of the landing gear) during **every daily inspection** until the aircraft is modified.\n- **Modification:** The aircraft must eventually be modified according to **Piper Service Bulletin 217** (a manufacturer's technical instruction).\n\n**Why it matters:**\nThe shock strut is critical for safe landings, especially for agricultural aircraft that operate from rough, unimproved airstrips. This AD addresses a known safety defect that could lead to landing gear failure. The \"inspect until modified\" approach allows continued operation while ensuring the problem is caught early, but mandates a permanent fix.\n\n**Who must comply:**\n- Owners and operators of affected PA-25-235 aircraft\n- Maintenance organisations servicing these aircraft\n\n**Key documents referenced:**\n- Piper Service Bulletin 217 (the modification standard)\n- FAA AD 63-17-5 (the equivalent US safety order)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-25-15-main-landing-gear-shock-strut-inspection-and-modification","history":"/api/acts/ad-pa-25-15-main-landing-gear-shock-strut-inspection-and-modification/history","analysis":"/api/acts/ad-pa-25-15-main-landing-gear-shock-strut-inspection-and-modification/analysis","conflicts":"/api/acts/ad-pa-25-15-main-landing-gear-shock-strut-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-pa-25-15-main-landing-gear-shock-strut-inspection-and-modification/important-cases","documents":"/api/acts/ad-pa-25-15-main-landing-gear-shock-strut-inspection-and-modification/documents"}}