{"id":"F2006B05981","name":"AD/PA-42/15 - Engine Mount Tubes and Barrel Nuts","slug":"ad-pa-42-15-engine-mount-tubes-and-barrel-nuts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":136184,"registerId":"commonwealth-F2006B05981-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-42/15 - Engine Mount Tubes and Barrel Nuts","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-42/15 Engine Mount Tubes and Barrel Nuts 3/88\n\nApplicability: All model PA-42 Cheyenne III with S/Nos 42-5527001 to 42-5527038. Requirement:  Action in accordance with Piper SB 873 Part I.\n\nCompliance: As per Requirement document.\n\n \n\nBackground: The manufacturer reports instances of cracks developing in the engine mount tubes at the engine attachment barrel nuts.\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":1420},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This directive remains tightly focused on its original purpose: addressing a specific structural defect (cracked engine mount tubes) in a specific batch of aircraft. It has not expanded beyond the original safety issue."},"complexity_factors":["Very short directive (under 150 words of substantive text)","Simple applicability criteria (specific aircraft model and serial number range)","Single external reference to manufacturer technical document (Piper SB 873)","No interpretation section, definitions, or conditional exceptions"],"plain_english_summary":"**What this does:** This is a safety directive requiring owners of specific Piper Cheyenne III aircraft to inspect and repair cracks in the engine mount tubes.\n\n**Who it affects:** Owners and operators of Piper PA-42 Cheyenne III aircraft with serial numbers between 42-5527001 and 42-5527038.\n\n**What you must do:** Follow the instructions in Piper Service Bulletin 873 Part I to check for and fix cracks in the engine mount tubes where they connect to the engine using barrel nuts (cylindrical fasteners).\n\n**Why it matters:** The manufacturer found cracks developing in these metal parts. If left unrepaired, these cracks could weaken the structure holding the engine to the aircraft, creating a serious flight safety risk."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-42-15-engine-mount-tubes-and-barrel-nuts","history":"/api/acts/ad-pa-42-15-engine-mount-tubes-and-barrel-nuts/history","analysis":"/api/acts/ad-pa-42-15-engine-mount-tubes-and-barrel-nuts/analysis","conflicts":"/api/acts/ad-pa-42-15-engine-mount-tubes-and-barrel-nuts/conflicts","importantCases":"/api/acts/ad-pa-42-15-engine-mount-tubes-and-barrel-nuts/important-cases","documents":"/api/acts/ad-pa-42-15-engine-mount-tubes-and-barrel-nuts/documents"}}