{"id":"F2006B07349","name":"AD/TB20/43 - Pitch Trim Actuator Seals","slug":"ad-tb20-43-pitch-trim-actuator-seals","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49442,"registerId":"commonwealth-F2006B07349-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)  \n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)  \n\nAerospatiale (Socata) TB20 (Trinidad) Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/TB20/43 Pitch Trim Actuator Seals 11/","sectionType":"part","heading":"AD/TB20/43 Pitch Trim Actuator Seals 11/2003","content":"# AD/TB20/43 Pitch Trim Actuator Seals 11/2003\n\nApplicability: TB 20 and TB 21 aircraft Serial Number (S/N) 2042, 2050, 2056 to 2118, 2123 to\n\n2125 and 2144.\n\nRequirement: Check and replace the pitch trim actuator tightness seals in accordance with EADS SOCATA Service Bulletin (S/B) TB No 10-135 dated April 2003.\n\nNote: DGAC AD 2003-286(A) refers.\n\nCompliance: At the next 100 hourly inspection or prior to 31 December 2003.\n\nThis Airworthiness Directive becomes effective on 30 October 2003.\n\nBackground: Non-conforming tightness seals fitted to the pitch trim actuator could lead to icing inside the actuator.\n\n![Signature of Jim Coyne Delegate of the Civil Aviation Safety Authority](image.002.png)  \n\nJim Coyne\n\nDelegate of the Civil Aviation Safety Authority 19 September 2003\n\n![](image.001.png)","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"No indication in this AD that the scope was altered from its original intent. The instrument specifies affected serial numbers (Applicability), directs inspection and replacement per the manufacturer Service Bulletin (Requirement), and sets the compliance timing (Compliance). It remains narrowly targeted to those listed TB20/TB21 aircraft for the stated icing-risk mitigation."},"complexity_factors":["Narrow, serial-numbered applicability means operators must check fleet records to determine if an aircraft is affected, adding administrative steps (Applicability).","Mandates work 'in accordance with' a manufacturer Service Bulletin (EADS SOCATA S/B TB No 10-135), creating dependency on external technical instructions and parts (Requirement).","Compliance window is conditional—at the next 100‑hour inspection or by a fixed date—so timing and urgency vary by utilisation rate of each aircraft (Compliance).","Safety rationale is technical (risk of icing inside actuator), so inspections/replacements require qualified maintenance and possible parts procurement (Background & Requirement).","Regulatory authority and enforceability derive from issuance under CASR subregulation 39.1(1) by a CASA delegate, limiting discretionary relief absent further regulatory action (front matter/signature).","Cost and operational burden fall on aircraft owners/operators (parts, labour, downtime); concentrated compliance on a small subset of the fleet increases per-aircraft cost (Applicability/Requirement)."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of specified Aerospatiale (Socata) TB20 and TB21 aeroplanes (listed serial numbers) to inspect and, if necessary, replace the pitch trim actuator tightness seals in accordance with EADS SOCATA Service Bulletin TB No 10-135. The measure targets a safety risk: non-conforming seals could allow icing inside the actuator. Compliance is at the next 100‑hour inspection or by 31 December 2003."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific manufacturing defect in a limited production run. The scope remains precisely limited to the identified unsafe condition."},"complexity_factors":["Single, specific mechanical issue (seal replacement)","Limited applicability (specific aircraft serial numbers only)","One clear compliance pathway (follow referenced service bulletin)","Simple deadline structure (next 100-hour inspection OR fixed date)","No nested conditions, exceptions, or defined terms section","Total length: approximately 200 words","Single cross-reference to French aviation authority directive (DGAC AD 2003-286(A)) for context only"],"plain_english_summary":"This safety order requires owners/operators of certain Socata TB20 and TB21 aircraft (S/N 2042, 2050, 2056–2118, 2123–2125, 2144) to inspect and replace seals in the pitch‑trim actuator per EADS SOCATA S/B TB No. 10‑135 (Apr 2003).\n\nWork must be done by the next 100‑hour inspection or by 31 Dec 2003, whichever is earlier, to prevent moisture‑induced icing that could jam the actuator and cause loss of trim control."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-tb20-43-pitch-trim-actuator-seals","history":"/api/acts/ad-tb20-43-pitch-trim-actuator-seals/history","analysis":"/api/acts/ad-tb20-43-pitch-trim-actuator-seals/analysis","conflicts":"/api/acts/ad-tb20-43-pitch-trim-actuator-seals/conflicts","importantCases":"/api/acts/ad-tb20-43-pitch-trim-actuator-seals/important-cases","documents":"/api/acts/ad-tb20-43-pitch-trim-actuator-seals/documents"}}