{"id":"F2006B05795","name":"AD/PA-31/90 - Rudder Trim Mechanism","slug":"ad-pa-31-90-rudder-trim-mechanism","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135701,"registerId":"commonwealth-F2006B05795-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-31/90 - Rudder Trim Mechanism","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-31 Series Aeroplanes\n\n \n\nAD/PA-31/90 Rudder Trim Mechanism 3/80\n\nApplicability: All model PA-31T with S/Nos. 31T-7400002 to 31T-8020007. All model PA-31T1 with S/Nos. 31T-7804001 to 31T-8004008.\n\n \n\nRequirement: Action in accordance with Piper SB No. 674. Compliance:  Within 100 hours time in service after 31 March 1980.\n\nBackground:  The manufacturer has determined that rudder trim travel may not meet specified requirements on the referenced aeroplanes.\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":2131},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This airworthiness directive maintains a narrow, technical scope focused solely on correcting a specific mechanical deficiency (rudder trim travel limits) in particular Piper aircraft. It addresses a discrete safety-of-flight issue identified by the manufacturer without expanding into broader operational, maintenance program, or airworthiness certification matters."},"complexity_factors":["Single compliance action referring to one external manufacturer document (Service Bulletin No. 674)","Narrow applicability limited to two specific aircraft models and defined serial number ranges","No defined terms, interpretation sections, or legislative cross-references","Simple time-based compliance trigger (100 hours time in service after a fixed date)","No exceptions, exemptions, conditional logic, or alternative compliance methods"],"plain_english_summary":"This mandatory Airworthiness Directive from CASA targets owners/operators of certain Piper PA‑31T and PA‑31T1 aeroplanes (specified serial ranges) and requires compliance with Piper Service Bulletin No. 674 to inspect and rectify the rudder trim mechanism. It matters because restricted trim travel can impede a pilot’s ability to maintain control across speeds and power settings. Work must be done within 100 hours time in service after 31 March 1980."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-31-90-rudder-trim-mechanism","history":"/api/acts/ad-pa-31-90-rudder-trim-mechanism/history","analysis":"/api/acts/ad-pa-31-90-rudder-trim-mechanism/analysis","conflicts":"/api/acts/ad-pa-31-90-rudder-trim-mechanism/conflicts","importantCases":"/api/acts/ad-pa-31-90-rudder-trim-mechanism/important-cases","documents":"/api/acts/ad-pa-31-90-rudder-trim-mechanism/documents"}}