{"id":"F2006B05975","name":"AD/PA-42/1 - Powerplant Firewall - Inspection","slug":"ad-pa-42-1-powerplant-firewall-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":136169,"registerId":"commonwealth-F2006B05975-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-42/1 - Powerplant Firewall - 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-42 (Cheyenne III) Series Aeroplanes\n\n \n\nAD/PA-42/1 Powerplant Firewall - Inspection 10/81\n\nApplicability: All model PA-42 with serial numbers 42-7800002 to 42-8001034. Document:  Piper SB No. 727.\n\nCompliance: Within 100 hours time in service after 31 October 1981, or prior to issue of certificate airworthiness, whichever occurs first.\n\n \n\nBackground: Some mounting holes in the firewall may have been left open and unplugged during manufacture.\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":2225},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This appears to be the original 1981 directive. The text contains no evidence of amendments or expansion beyond the original scope of inspecting firewalls on specific PA-42 aircraft for manufacturing defects."},"complexity_factors":["Single, specific applicability limited to one aircraft model and serial number range","Brief operative requirement with reference to external technical document (Piper Service Bulletin No. 727)","Simple conditional compliance deadline (alternative dates)"],"plain_english_summary":"**What this directive requires**\n\nThis safety order mandates an inspection of the engine firewall—the protective barrier separating the engine compartment from the passenger cabin—on specific Piper aircraft.\n\n**Who it affects**\nOwners and operators of Piper PA-42 Cheyenne III aeroplanes with serial numbers between 42-7800002 and 42-8001034.\n\n**What must be done**\nThe firewall must be inspected to identify any mounting holes that were left open and unplugged during manufacturing. The technical specifications for this inspection are contained in Piper Service Bulletin No. 727.\n\n**When to comply**\nThe inspection must be completed within 100 hours of flight time after 31 October 1981, or before the aircraft receives its certificate of airworthiness (its official safety approval)—whichever occurs first.\n\n**Why it matters**\nUnplugged holes in the firewall could compromise its ability to contain fire, smoke, or toxic fumes, potentially allowing them to enter the cabin from the engine compartment."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-42-1-powerplant-firewall-inspection","history":"/api/acts/ad-pa-42-1-powerplant-firewall-inspection/history","analysis":"/api/acts/ad-pa-42-1-powerplant-firewall-inspection/analysis","conflicts":"/api/acts/ad-pa-42-1-powerplant-firewall-inspection/conflicts","importantCases":"/api/acts/ad-pa-42-1-powerplant-firewall-inspection/important-cases","documents":"/api/acts/ad-pa-42-1-powerplant-firewall-inspection/documents"}}