{"id":"F2006B05597","name":"AD/PA-28/39 - Stabilator - Inspection and Drilling of Drain Holes","slug":"ad-pa-28-39-stabilator-inspection-and-drilling-of-drain-holes","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135207,"registerId":"commonwealth-F2006B05597-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-28/39 - Stabilator - Inspection and Drilling of Drain Holes","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-28/39 Stabilator - Inspection and Drilling of Drain Holes 9/72\n\nApplicability: Models PA-28-140, PA-28-150, PA-28-160, PA-28-180, PA-28R-180, PA-28R-200 and PA-28-235.\n\n \n\nDocument: Piper SL No. 615.\n\n \n\nCompliance: Within 100 hours time in service after 29 September 1972.\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\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2030},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"The directive maintains its original narrow scope—a specific one-time maintenance action (inspection and drilling) for specific aircraft models. There is no evidence of scope creep or expansion beyond the original safety intent."},"complexity_factors":["Single-page document with one specific maintenance requirement","No defined terms or interpretation section","Simple applicability list (7 specific aircraft models)","No conditional logic, exceptions, or cross-references to other legislation","Clear, unambiguous compliance deadline (100 hours time in service)"],"plain_english_summary":"This Airworthiness Directive (AD) mandates a safety inspection and modification for specific **Piper Cherokee aircraft** (models PA-28-140, PA-28-150, PA-28-160, PA-28-180, PA-28R-180, PA-28R-200, and PA-28-235).\n\n**What it requires:**\n- **Inspection** of the **stabilator** (the movable horizontal tail surface that controls the aircraft's up/down pitch)\n- **Drilling drain holes** in the stabilator structure to allow trapped water to escape\n- Completion within **100 hours of flight time** after 29 September 1972\n\n**Who must comply:**\nOwners and operators of the listed Piper PA-28 models.\n\n**Why it matters:**\nWater trapped inside aircraft control surfaces can cause corrosion or freeze in flight, potentially jamming the stabilator and causing loss of control. Draining prevents this safety hazard.\n\nThe technical details for the drilling procedure are found in **Piper Service Letter No. 615**."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-28-39-stabilator-inspection-and-drilling-of-drain-holes","history":"/api/acts/ad-pa-28-39-stabilator-inspection-and-drilling-of-drain-holes/history","analysis":"/api/acts/ad-pa-28-39-stabilator-inspection-and-drilling-of-drain-holes/analysis","conflicts":"/api/acts/ad-pa-28-39-stabilator-inspection-and-drilling-of-drain-holes/conflicts","importantCases":"/api/acts/ad-pa-28-39-stabilator-inspection-and-drilling-of-drain-holes/important-cases","documents":"/api/acts/ad-pa-28-39-stabilator-inspection-and-drilling-of-drain-holes/documents"}}