{"id":"F2006B07289","name":"AD/TB10/21 Amdt 2 - Exhaust System Clamp Locknuts","slug":"ad-tb10-21-amdt-2-exhaust-system-clamp-locknuts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49250,"registerId":"commonwealth-F2006B07289-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TB10/21 Amdt 2 - Exhaust System Clamp Locknuts","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nAerospatiale (Socata) TB9 and TB10 (Tobago) Series Aeroplanes\n\nAD/TB10/21\n\nAmdt 2\n\n  \nExhaust System Clamp Locknuts 5/97\n\nApplicability: All TB9 aircraft not incorporating HSJ Aviation (HSJ) Engineering Order HSJ 1289 or Auto Avia Drawings 92/334/D1 or 92/334/DR Issue 2, and HSJ Engineering Order HSJ 1486.\n\nRequirement: To prevent failure of the exhaust system; inspect, modify and assemble the exhaust system in accordance with the requirements of Socata Service Bulletin No.\n\nSB 10-072-78 Amendment 2.\n\nNote: DGAC Airworthiness Directive 92-152(A)R4 refers.\n\nCompliance: Unless previously accomplished in accordance with Amendment 1 of this Directive; within 50 hours time in service after 24 April 1997, and thereafter at each disassembly of the exhaust system.\n\nThis Amendment becomes effective on 24 April 1997.\n\nBackground: This Directive was originally issued to address concern for the integrity of the TB9 exhaust system following two TB10 in-flight exhaust system separation events in Australia. Amendment 1 of the Directive reflected the manufacturer's revision to the part numbers of the replacement exhaust pipe and the long manifold to exhaust clamps. This amendment reflects the manufacturer’s second revision to the requirement document. The revision, in part, introduces a new exhaust pipe to engine cylinder seal part number and revises the exhaust assembly torque data.\n\nAmendment 1 of this Airworthiness Directive became effective on 28 March 1996. The original issue of this Airworthiness Directive became effective on 26 May 1994.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This amendment updates the manufacturer’s requirement document by introducing a new exhaust pipe-to-engine cylinder seal part number and revising exhaust assembly torque data. Earlier amendments had already revised replacement part numbers for pipes and clamps; this further refines the technical specifications operators must adopt, but does not broaden applicability beyond the TB9 aircraft group identified in the directive."},"complexity_factors":["Cross-reference to external mandatory document (Socata Service Bulletin SB 10-072-78 Amendment 2) — compliance depends on that technical document.","Specific applicability carve-outs referencing HSJ Engineering Orders and Auto Avia drawings create conditional scope.","Timing requirement: initial compliance within 50 hours TIS after specified date and recurrent inspection at each exhaust disassembly.","Technical change history: multiple amendments and revised part numbers/torque data increase traceability and record‑checking burden.","Operational impact on owners/operators: requires parts/maintenance actions and recordkeeping.","Reference to foreign AD (DGAC 92-152(A)R4) adds secondary verification context."],"plain_english_summary":"Requires inspection, modification and reassembly of the TB9 exhaust system clamp locknuts in accordance with Socata Service Bulletin SB 10-072-78 Amendment 2 to prevent in‑flight exhaust separation. It applies to TB9 aircraft that do not already incorporate specified HSJ or Auto Avia engineering orders/drawings. Aircraft owners/operators must carry out the work within 50 hours flying time after 24 April 1997 and each time the exhaust is disassembled, and must adopt revised part numbers and torque data set out by the manufacturer."},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"The original 1994 directive addressed exhaust system integrity broadly following in-flight separation incidents. Amendment 1 (1996) expanded scope to cover revised part numbers for replacement components. Amendment 2 (1997) further expanded scope to include new seal part numbers and revised torque specifications. The directive has evolved from a simple inspection/fix order to a detailed technical specification incorporating multiple manufacturer revisions, growing beyond the original 'inspect and fix' intent to encompass precise assembly standards and recurring maintenance obligations."},"complexity_factors":["Multiple applicability exclusions requiring cross-checking against three different engineering documents (HSJ 1289, Auto Avia Drawings 92/334/D1 or 92/334/DR Issue 2, HSJ 1486)","Requires reference to external manufacturer document (Socata Service Bulletin SB 10-072-78 Amendment 2) not reproduced in the directive itself","Nested effective dates with three historical versions (original 1994, Amendment 1 1996, Amendment 2 1997)","Conditional compliance language ('Unless previously accomplished in accordance with Amendment 1')","Ongoing obligation ('thereafter at each disassembly') creates perpetual compliance duty"],"plain_english_summary":"This directive requires owners/operators of Aerospatiale (Socata) TB9 and TB10 Tobago aircraft to inspect, modify and reassemble the exhaust system per Socata Service Bulletin SB 10-072-78 (Amendment 2) to prevent in‑flight exhaust separation. It primarily targets TB9s that have not received specified HSJ/Auto Avia modifications.\n\nWork must be done within 50 flight hours after 24 April 1997 and whenever the exhaust is reinstalled, to avoid engine loss, fire, or cabin CO risk."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tb10-21-amdt-2-exhaust-system-clamp-locknuts","history":"/api/acts/ad-tb10-21-amdt-2-exhaust-system-clamp-locknuts/history","analysis":"/api/acts/ad-tb10-21-amdt-2-exhaust-system-clamp-locknuts/analysis","conflicts":"/api/acts/ad-tb10-21-amdt-2-exhaust-system-clamp-locknuts/conflicts","importantCases":"/api/acts/ad-tb10-21-amdt-2-exhaust-system-clamp-locknuts/important-cases","documents":"/api/acts/ad-tb10-21-amdt-2-exhaust-system-clamp-locknuts/documents"}}