{"id":"F2006B02899","name":"AD/B737/199 - Aileron Transfer Mechanism Lower Bearing Support at First Officer Position","slug":"ad-b737-199-aileron-transfer-mechanism-lower-bearing-support-at-first-officer-position","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42241,"registerId":"commonwealth-F2006B02899-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B737/199 - Aileron Transfer Mechanism Lower Bearing Support at First Officer Position","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)  \n\nAIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \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 CAR 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\nBoeing 737 Series Aeroplanes\n\nAD/B737/199 Aileron Transfer Mechanism Lower Bearing\n\nSupport at First Officer Position\n\n  \n12/2002\n\nApplicability: Model 737-100, \\-200, \\-200C, \\-300, \\-400, and \\-500 series aircraft, line numbers 1\n\nthrough 3132.\n\nRequirement: Inspect in accordance with the technical requirements of FAA AD 2002-18-02 Amdt 39-12874.\n\nNote: Boeing Alert Service Bulletin 737-27A1238 refers.\n\nCompliance: As specified in the Requirement document.\n\nThis Airworthiness Directive becomes effective on 28 November 2002.\n\nBackground: This Directive requires a one-time inspection to determine whether the lo wer bearing support of the aileron transfer mechanism directly below the first officer’s control column has a ‘pocket’, and follow-on corrective actions, if necessary. The actions specified by this Directive are intended to prevent jamming of the first officer’s control wheel due to the presence of a foreign object on the lower bearing support of the transfer mechanism, which could result in reduced controllability of the aeroplane.\n\n![Signature of Steven John Swift, Delegate of the Civil Aviation Safety Authority.](image.002.png)  \n\nSteven John Swift\n\nDelegate of the Civil Aviation Safety Authority 18 October 2002\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 6 November 2002.\n\n  \nPage 1 of 1","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope: a specific safety inspection for a specific mechanical defect on specific aircraft models. There is no evidence of scope creep; it remains a targeted technical safety measure as originally intended."},"complexity_factors":["Very short document (1 page)","Only 3 operative sections: Applicability, Requirement, and Compliance","Single defined term ('pocket') explained in plain language in the Background","No nested exceptions or conditional logic — straightforward 'inspect and fix if needed' structure","Cross-references only to external technical documents (FAA AD and Boeing Service Bulletin) rather than internal legislative provisions","No interpretation section with multiple defined terms"],"plain_english_summary":"This safety order requires operators of older Boeing 737 models (line numbers 1–3132) to perform a one-time inspection of the aileron transfer mechanism beneath the first officer’s control column for a manufacturing “pocket” in a bearing support. Debris trapped there could jam the first officer’s control wheel and reduce steering control. If found, repairs must follow FAA AD 2002‑18‑02; the directive effective date was 28 Nov 2002."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD is narrowly targeted at a single identified unsafe condition (potential foreign‑object jamming at the lower bearing support beneath the first officer’s control column) for specific Boeing 737 series and line‑numbers. It does not expand into broader maintenance regimes, recurring inspection cycles, or additional aircraft types. The directive imports technical instructions from the FAA and Boeing but remains within its original, limited safety‑correction purpose."},"complexity_factors":["Single‑page, single subject AD with one main action (one‑time inspection)","Cross‑references to external technical documents (FAA AD 2002-18-02 and Boeing Alert Service Bulletin 737-27A1238)","Limited applicability (specific models and line numbers 1–3132) with no nested exceptions","Compliance timing and corrective details are defined in the external FAA/Boeing documents rather than in the AD itself (adds minor complexity)","Short background and clear single safety concern (bearing support 'pocket' leading to possible jamming)"],"plain_english_summary":"**What this instrument does (mechanically):**\n\n- It is an Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) requiring a one‑time inspection of a specific part of the aileron transfer mechanism located directly under the first officer’s control column on certain Boeing 737 aeroplanes (models -100, -200, -200C, -300, -400 and -500, line numbers 1–3132).\n- The AD does not set out new technical steps itself; instead it makes compliance with the technical requirements of FAA AD 2002-18-02 mandatory for Australian operators. Boeing Alert Service Bulletin 737-27A1238 is noted as a related document.\n- If the inspection finds the described defect (a \"pocket\" on the lower bearing support) operators must carry out the follow‑on corrective actions specified in the referenced technical document.\n- The AD’s required timing is those timings specified in the referenced FAA AD (the Compliance section refers operators to that document).\n\n**Who this affects:**\n\n- Aircraft operators, maintenance organisations and engineers responsible for the listed Boeing 737 models and within the specified line‑number range. Owners/operators pay for the inspection and any corrective work, and they must schedule the aircraft for that work.\n- The CASA delegate (as regulator) enforces the directive; the AD imports technical detail from the FAA AD and Boeing service information, so FAA/Boeing documents determine the exact inspection method and corrective steps.\n\n**Why it matters (stated purpose and practical effect):**\n\n- Stated purpose: to detect and, if necessary, correct a condition where the lower bearing support of the aileron transfer mechanism has a \"pocket\" that could collect a foreign object and jam the first officer’s control wheel. The safety effect is to reduce the risk of reduced controllability of the aeroplane.\n- Practical effect: a one‑time maintenance action (inspection) and potentially repair or replacement if a defect/foreign object is found. This reduces a low‑frequency mechanical risk at the cost of maintenance labour, possible parts and aircraft downtime.\n\n**Costs, incentives and implementation trade‑offs:**\n\n- Who pays: the aircraft operator. Costs are inspection labour, any corrective repairs/parts, and aircraft out‑of‑service time. Those costs are concentrated on affected operators; benefits (reduced accident risk) are diffuse across passengers and the public.\n- Who decides: CASA (via its delegate) mandates compliance; detailed inspection and corrective procedures are decided by the FAA AD and Boeing service bulletin that the AD incorporates.\n- Incentives and behaviour change: operators must schedule the inspection; maintenance providers will perform the prescribed work. Because the AD is one‑time, it does not impose ongoing recurrent costs, but corrective actions could vary in scope and cost depending on findings.\n- Implementation risk: reliance on external documents (FAA AD/Boeing bulletin) means operators must obtain and follow those documents precisely; ambiguity in cross‑referenced material can delay compliance. Aircraft availability and scheduling are the main operational constraints.\n\n**Other practical notes:**\n\n- The AD covers only older 737 series up to line number 3132; later production aircraft or other models are outside scope unless otherwise designated.\n- The directive is narrowly focused and prescriptive: it requires an inspection and any corrective action specified by the referenced FAA/Boeing documents. It does not create a continuing surveillance programme or new certification requirements beyond the specified inspection and corrections.\n\n(References: Applicability, Requirement, Compliance and Background sections of the AD.)"},"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-b737-199-aileron-transfer-mechanism-lower-bearing-support-at-first-officer-position","history":"/api/acts/ad-b737-199-aileron-transfer-mechanism-lower-bearing-support-at-first-officer-position/history","analysis":"/api/acts/ad-b737-199-aileron-transfer-mechanism-lower-bearing-support-at-first-officer-position/analysis","conflicts":"/api/acts/ad-b737-199-aileron-transfer-mechanism-lower-bearing-support-at-first-officer-position/conflicts","importantCases":"/api/acts/ad-b737-199-aileron-transfer-mechanism-lower-bearing-support-at-first-officer-position/important-cases","documents":"/api/acts/ad-b737-199-aileron-transfer-mechanism-lower-bearing-support-at-first-officer-position/documents"}}