{"id":"F2006B07333","name":"AD/TB20/29 - Airworthiness Limitations","slug":"ad-tb20-29-airworthiness-limitations","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49384,"registerId":"commonwealth-F2006B07333-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TB20/29 - Airworthiness Limitations","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)  Aerospatiale (Socata) TB20 (Trinidad) Series Aeroplanes\n\n \n\nAD/TB20/29 Airworthiness Limitations 10/94\n\nApplicability: All model TB20.\n\n \n\nRequirement: Retire TB20 parts in accordance with the table of retirement lives in Part F-3 of Aerospatiale TB Aircraft Service Letter Nr 14/1, dated January 1989.\n\n \n\nCompliance: Retirement lives are effective from 15 September 1994.\n\n \n\nBackground: The wing retirement life specified in this AD was as established by the manufacturer by analysis.\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":1665},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive remains strictly limited to its original purpose: establishing retirement lives for TB20 aircraft parts based on manufacturer analysis. There is no indication of expansion into unrelated operational or maintenance areas."},"complexity_factors":["Extremely short length (under 150 words)","Single unambiguous requirement with no exceptions","Only one external reference (manufacturer service letter)","No defined terms or legislative cross-references"],"plain_english_summary":"**What this does:** Sets mandatory 'use-by dates' for aircraft parts on Aerospatiale (Socata) TB20 Trinidad aeroplanes. Once parts reach a specific age or number of flight hours, they must be permanently removed from service ('retired').\n\n**Who it affects:** Owners and operators of all TB20 model aircraft registered in Australia.\n\n**What you must do:** Replace or remove specific components (including the wing) according to the retirement时间表 found in Part F-3 of the manufacturer's **Service Letter Nr 14/1** (dated January 1989). You cannot fly the aircraft once these parts exceed their allowed lifespan.\n\n**Why it matters:** Prevents catastrophic structural failures caused by metal fatigue. The manufacturer calculated these limits through engineering analysis to ensure the aircraft remains safe as it ages.\n\n**Key date:** These retirement limits became mandatory from **15 September 1994**."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tb20-29-airworthiness-limitations","history":"/api/acts/ad-tb20-29-airworthiness-limitations/history","analysis":"/api/acts/ad-tb20-29-airworthiness-limitations/analysis","conflicts":"/api/acts/ad-tb20-29-airworthiness-limitations/conflicts","importantCases":"/api/acts/ad-tb20-29-airworthiness-limitations/important-cases","documents":"/api/acts/ad-tb20-29-airworthiness-limitations/documents"}}