{"id":"F2006B07332","name":"AD/TB20/28 Amdt 1 - Front Seats","slug":"ad-tb20-28-amdt-1-front-seats","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49381,"registerId":"commonwealth-F2006B07332-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TB20/28 Amdt 1 - Front Seats","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) TB20 (Trinidad) Series Aeroplanes\n\nAD/TB20/28\n\nAmdt 1\n\n  \nFront Seats 13/94\n\nApplicability: Model TB20 & TB21 aircraft front seats with a tilting back-rest, installed from February 1991 on aircraft up to S/N 1479; except aircraft S/N 1192, 1193, 1308, 1426\n\nthru 1433, 1448, 1461, 1462, 1464 thru 1469, 1471, & 1473 thru 1477.\n\nRequirement: Action in accordance with Socata TB Service Bulletin 10-075-25 Amendment 1.\n\nNote: DGAC AD 94-114(A)R1 refers.\n\nCompliance: Unless already accomplished, within 50 hours time in service after 8 December 1994, or at the next inspection for maintenance release issue, whichever occurs first.\n\nBackground: The DGAC requires reinforcement of the front seat structure. Amendment 1 is issued to reflect an amendment of the manufacturer’s bulletin which clarifies applicability and weld filler material.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a narrow, technical amendment to an existing Airworthiness Directive. It clarifies which aircraft serial numbers are affected and updates welding material specifications. The scope remains tightly focused on front seat structural integrity for a specific aircraft model range."},"complexity_factors":["Single, specific requirement (seat reinforcement)","Clear applicability clause with explicit serial number exceptions","Simple compliance deadline (50 hours or next inspection)","No defined terms section","No cross-referencing to other legislation","Background limited to one sentence explaining the safety rationale"],"plain_english_summary":"This is an **Airworthiness Directive** — essentially a mandatory safety notice for aircraft owners and operators. It applies to specific **Socata TB20 and TB21 aeroplanes** (small, single-engine planes) built between February 1991 and serial number 1479, with some exceptions.\n\n**What it requires:**\n- Owners must **reinforce the front seat structure** in affected aircraft\n- The work must follow the manufacturer's specific instructions (Service Bulletin 10-075-25 Amendment 1)\n\n**Who must comply:**\n- Operators of the specified aircraft models that haven't already made the fix\n\n**When to do it:**\n- Within **50 hours of flying time** after 8 December 1994, **or** at the next scheduled maintenance check — whichever comes first\n\n**Why it matters:**\nThe French aviation authority (DGAC) identified a structural weakness in the front seats that could fail in an accident. This directive ensures seats won't collapse under stress, protecting pilots and passengers. The amendment simply updates which planes are affected and what welding materials to use."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment 1 updates the manufacturer’s service bulletin and the AD to clarify which aircraft (applicability) are affected and to specify the weld filler material to be used for the front seat reinforcement. The directive therefore narrows implementation uncertainty by altering the bulletin’s technical and applicability details rather than expanding the set of required actions. (Background)"},"complexity_factors":["Narrow, vehicle-specific applicability with an explicit list of excluded serial numbers (Applicability)","Single mandated corrective action referenced to a manufacturer service bulletin rather than prescribing technical steps in the AD itself (Requirement)","Short compliance window tied to flight hours or next maintenance release, requiring scheduling and potential operational disruption (Compliance)","Technical detail (weld filler material) delegated to the amended service bulletin, creating reliance on the manufacturer's document for implementation (Background)","Limited number of affected components (front seats) and clear deadline reduces regulatory layering and ambiguity"],"plain_english_summary":"Owners/operators of certain Socata TB20 and TB21 aeroplanes with tilting front seats must strengthen the front seat structure by completing the manufacturer’s Service Bulletin (Socata TB SB 10‑075‑25 Amendment 1). If not already done, the work is mandatory within 50 hours TIS after 8 December 1994 or at the next maintenance release, whichever comes first. Owners bear costs; the amendment clarifies affected serials and the weld filler material to use."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tb20-28-amdt-1-front-seats","history":"/api/acts/ad-tb20-28-amdt-1-front-seats/history","analysis":"/api/acts/ad-tb20-28-amdt-1-front-seats/analysis","conflicts":"/api/acts/ad-tb20-28-amdt-1-front-seats/conflicts","importantCases":"/api/acts/ad-tb20-28-amdt-1-front-seats/important-cases","documents":"/api/acts/ad-tb20-28-amdt-1-front-seats/documents"}}