{"id":"F2005L03573","name":"AD/B737/267 - Aft Engine Mount Secondary Support","slug":"ad-b737-267-aft-engine-mount-secondary-support","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":39145,"registerId":"commonwealth-F2005L03573-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Boeing 737 Series Aeroplanes","sectionType":"division","heading":"Boeing 737 Series Aeroplanes","content":"### Boeing 737 Series Aeroplanes\n\n| AD/B737/267 | Aft Engine Mount Secondary Support | 13/2005 |\n| ----------- | ---------------------------------- | ------- |\n\n| Applicability: | All Model 737-100, -200, and -200C series aircraft.                                                                                                                                                                                                                                                                                                           |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with the technical requirements of FAA AD 99-26-07Amdt 39-11466.                                                                                                                                                                                                                                                                         |\n| Compliance:    | As specified in the Requirement document.                                                                                                                                                                                                                                                                                                                     |\n|                | This Airworthiness Directive becomes effective on 22 December 2005.                                                                                                                                                                                                                                                                                           |\n| Background:    | This Directive requires inspections to detect missing nuts and/or damaged secondary support hardware adjacent to the aft engine mount, and eventual terminating action. The Directive was prompted by the FAA’s determination that the repetitive inspections may not be providing the degree of safety assurance necessary for the transport aircraft fleet. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n11 November 2005","sortOrder":0},{"sectionNumber":"AD/B737/267","sectionType":"part","heading":"AD/B737/267","content":"## AD/B737/267","sortOrder":1},{"sectionNumber":"Aft Engine Mount Secondary Support","sectionType":"part","heading":"Aft Engine Mount Secondary Support","content":"## Aft Engine Mount Secondary Support","sortOrder":2},{"sectionNumber":"13/2005","sectionType":"part","heading":"13/2005","content":"## 13/2005","sortOrder":3}],"analysis":{"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":2,"scope_assessment":{"changed":false,"description":"This is a standard airworthiness directive adopting an FAA safety mandate. The scope remains tightly focused on the specific mechanical issue (aft engine mount hardware) for the specified aircraft models. There is no evidence of scope creep; it does exactly what it says on the tin."},"complexity_factors":["Extremely short document (under 300 words)","Only one substantive requirement: comply with external FAA directive","No defined terms section — relies entirely on referenced FAA document","No conditional logic or nested exceptions in the text itself","Simple applicability test (three specific aircraft models)","Single compliance pathway with clear end-date for effectiveness"],"plain_english_summary":"This Airworthiness Directive requires Australian owners/operators of Boeing 737-100, -200 and -200C aircraft to inspect the aft engine mount secondary support for missing nuts and damaged hardware, and to carry out the FAA-prescribed terminating repair so repetitive inspections are no longer needed.\n\nIt adopts FAA AD 99-26-07 to prevent possible engine separation and becomes mandatory from 22 December 2005."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive adopts and applies the FAA AD's technical requirements to the specified Australian‑registered fleet without expanding applicability or adding new obligations beyond those referenced. The instrument's scope aligns with the FAA‑identified unsafe condition and defers procedural specifics to FAA AD 99-26-07Amdt 39-11466 (Requirement; Background; Applicability)."},"complexity_factors":["Cross-reference to an external FAA AD for all technical requirements creates dependence on a non‑Australian instrument for substantive detail (Requirement: 'Action in accordance with the technical requirements of FAA AD 99-26-07Amdt 39-11466').","Applicability covers all Model 737-100, -200 and -200C series, so the operator population is clearly defined but broad (Applicability: 'All Model 737-100, -200, and -200C series aircraft').","Mandates inspections and an unspecified 'terminating action', with the precise tasks and intervals defined in the referenced FAA AD rather than in this instrument (Requirement; Background: 'eventual terminating action').","Compliance language delegates timing and procedures to the Requirement document, which can create interpretation and implementation burden for operators who must obtain and follow the FAA AD (Compliance: 'As specified in the Requirement document').","Effective date and formal issuance by the CASA delegate fix the regulatory start point and identify the regulatory decision-maker (Effective date: 'This Airworthiness Directive becomes effective on 22 December 2005'; signed by David Villiers, Delegate).","Cost and operational burden fall on aircraft operators, who fund inspections, corrective work and the terminating action implied by the directive (implied by Requirement and Applicability).","Rationale is safety-driven and cites the FAA's view that repeated inspections may not be sufficient, which explains the move to a terminating action but leaves risk‑management specifics to the FAA AD (Background: 'FAA’s determination that the repetitive inspections may not be providing the degree of safety assurance necessary')."],"plain_english_summary":"Requires operators of all Boeing 737-100, -200 and -200C series aeroplanes to inspect the aft engine-mount secondary support for missing nuts or damaged hardware and to carry out a specified terminating action by following the technical requirements of FAA AD 99-26-07Amdt 39-11466. CASA issued the directive effective 22 December 2005 after the FAA concluded repetitive inspections alone might not provide adequate assurance. Operators must pay for inspections, repairs and follow an externally referenced technical standard."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-267-aft-engine-mount-secondary-support","history":"/api/acts/ad-b737-267-aft-engine-mount-secondary-support/history","analysis":"/api/acts/ad-b737-267-aft-engine-mount-secondary-support/analysis","conflicts":"/api/acts/ad-b737-267-aft-engine-mount-secondary-support/conflicts","importantCases":"/api/acts/ad-b737-267-aft-engine-mount-secondary-support/important-cases","documents":"/api/acts/ad-b737-267-aft-engine-mount-secondary-support/documents"}}