{"id":"F2008L00594","name":"AD/B767/235 - ECS Duct Assembly Insulation","slug":"ad-b767-235-ecs-duct-assembly-insulation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":119565,"registerId":"commonwealth-F2008L00594-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Boeing 767 Series Aeroplanes","sectionType":"division","heading":"Boeing 767 Series Aeroplanes","content":"### Boeing 767 Series Aeroplanes\n\n| AD/B767/235 | ECS Duct Assembly Insulation | 3/2008 |\n| ----------- | ---------------------------- | ------ |\n\n| Applicability: | Model 767-200 and 767-300 series aircraft, as identified in Boeing Service Bulletin 767-21A0167 Revision 1, or later FAA approved revision; excluding variable number VK031.                                                                                                                                                                                                                                                                                                                                                                               |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with the technical requirements of FAA AD 2008-02-16 Amdt 39-15346.                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n| Compliance:    | As specified in the Requirement document, with a revised effective date of13 March 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n|                | This Airworthiness Directive becomes effective on 13 March 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |\n| Background:    | The FAA received reports of duct assemblies in the environmental control system (ECS) with burned BMS 8-39 polyurethane foam insulation. Also a report received from the manufacturer that aircraft were assembled with duct assemblies in the ECS wrapped with BMS 8-39 polyurethane foam insulation, a material of which the fire retardant properties deteriorate with age. The actions of this Directive are intended to prevent a potential electrical arc from igniting the BMS 8-39 polyurethane foam insulation on the duct assemblies of the ECS. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n1 February 2008","sortOrder":0},{"sectionNumber":"AD/B767/235","sectionType":"part","heading":"AD/B767/235","content":"## AD/B767/235","sortOrder":1},{"sectionNumber":"ECS Duct Assembly Insulation","sectionType":"part","heading":"ECS Duct Assembly Insulation","content":"## ECS Duct Assembly Insulation","sortOrder":2},{"sectionNumber":"3/2008","sectionType":"part","heading":"3/2008","content":"## 3/2008","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD adopts the requirements of FAA AD 2008-02-16 for the specified Boeing 767-200/300 aircraft as identified in Boeing Service Bulletin 767-21A0167 (excluding VK031). It mirrors the FAA action and does not expand the set of affected aircraft or the mandated technical actions beyond that FAA requirement."},"complexity_factors":["Cross-reference to an external FAA AD (FAA AD 2008-02-16) rather than prescribing standalone procedures","Reliance on Boeing Service Bulletin 767-21A0167 (or later FAA-approved revision) to identify affected aircraft","Narrow applicability (specific 767-200/300 models) with explicit exclusion (variable number VK031)","Technical nature of the work (inspection/repair/replacement of BMS 8-39 polyurethane foam insulation) requiring specialised maintenance capability","Compliance timing (effective date specified: 13 March 2008) and potential need to track later FAA-approved revisions","Costs and operational disruption borne by aircraft owners/operators (inspection and repair downtime)","Regulatory enforcement by CASA based on externally authored technical materials"],"plain_english_summary":"This Airworthiness Directive requires operators of Boeing 767-200 and 767-300 series aircraft (excluding variable number VK031) to carry out the inspections and corrective work specified in FAA AD 2008-02-16 to remove or repair BMS 8‑39 polyurethane foam insulation on environmental control system (ECS) ducting. Aircraft owners/operators pay for and arrange the work; the Civil Aviation Safety Authority enforces compliance. The stated aim is to prevent ignition of deteriorated foam from an electrical arc."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow airworthiness directive addressing a specific safety defect in specific aircraft. It has not expanded beyond its original purpose of mandating corrective action for the ECS insulation fire risk."},"complexity_factors":["Very short document (under 300 words)","Only 1 defined term implicitly used (ECS - Environmental Control System, explained in Background)","Single cross-reference to external FAA directive (AD 2008-02-16) which contains the actual technical requirements","Simple conditional logic: applicability is straightforward model-based exclusion (all 767-200/300 series except VK031)","No nested exceptions or complex procedural requirements within the document itself — all technical detail is 'incorporated by reference' to the FAA document"],"plain_english_summary":"This CASA Airworthiness Directive mandates corrective action on certain Boeing 767-200/-300 aircraft to address aging BMS 8-39 foam insulation in the environmental control system that can lose fire resistance and ignite from electrical arcing. Affected operators (except one specified aircraft, VK031) must follow the FAA’s required procedures (inspections, replacements or modifications per FAA AD 2008-02-16). The goal is to eliminate a potential in-flight fire hazard."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b767-235-ecs-duct-assembly-insulation","history":"/api/acts/ad-b767-235-ecs-duct-assembly-insulation/history","analysis":"/api/acts/ad-b767-235-ecs-duct-assembly-insulation/analysis","conflicts":"/api/acts/ad-b767-235-ecs-duct-assembly-insulation/conflicts","importantCases":"/api/acts/ad-b767-235-ecs-duct-assembly-insulation/important-cases","documents":"/api/acts/ad-b767-235-ecs-duct-assembly-insulation/documents"}}