{"id":"F2008L04561","name":"AD/B737/348 - AN-26 Insulation Blankets","slug":"ad-b737-348-an-26-insulation-blankets","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":120864,"registerId":"commonwealth-F2008L04561-current","compilationNumber":null,"startDate":"2026-04-03","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/B737/348 | AN-26 Insulation Blankets | 1/2009 |\n| ----------- | ------------------------- | ------ |\n\n| Applicability: | Boeing 737-200, 737-200C, 737-300, and 737-400 series aircraft, serial numbers as defined in Boeing Special Attention Service Bulletin 737-25-1572.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Either:a. Remove all insulation blankets from the pressurized areas of the fuselage and install new insulation blankets using a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA. The new insulation blankets must comply with 14 Code of Federal Regulations (CFR) 25.856(a). The areas where the affected insulation blankets are installed include, but are not limited to, the following areas:(i) Crown area of the airplane;(ii) Areas behind flight deck panels and circuit breaker panels;(iii) Areas behind sidewalls, lavatories, closets, and galleys;(iv) Cargo compartment areas;(v) Air ducting;(vi) Waste and water tubing; and(vii) Areas attached to the underside of floor panels. ; orb. Remove the existing fuselage insulation blankets and install new insulation blankets, in accordance with the Accomplishment Instructions of the Boeing Special Attention Service Bulletin 737-25-1572.However, these actions are not required for any insulation blanket that is determined not to be constructed of Orcon Orcofilm AN-26, using an identification method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA or in accordance with Appendix A of Boeing Special Attention Service Bulletin 737-25-1572.2. No person may install any insulation blanket constructed of AN-26 as a replacement unless it has been modified to comply with 14 CFR 25.856(a). |\n\n|             | Note 1: Insulation material that is part-marked with a date of manufacture indicating that it was manufactured before July 1981 or after December 1988 is not constructed of AN-26.Note 2: FAA AD 2008-23-09 refers.                                                                                                                                                                                                                                                                                                                                                                                                                       |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Compliance: | 1. Within 96 months after the effective date of this Airworthiness Directive.2. After the effective date of this Airworthiness Directive.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |\n|             | This Airworthiness Directive becomes effective on 15 January 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |\n| Background: | This Airworthiness Directive results from reports of in-flight and ground fires on certain airplanes manufactured with insulation blankets covered with a specific polyethyleneteraphthalate (PET), ORCON Orcofilm AN-26 (all variants, including AN-26, AN-26A, and AN-26B), which may contribute to the spread of a fire when ignition occurs from sources such as electrical arcing. We are issuing this Airworthiness Directive to ensure that insulation blankets constructed of AN-26 are removed from the fuselage. Such insulation blankets could ignite and propagate a fire that is the result of electrical arcing or sparking. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n24 November 2008","sortOrder":0},{"sectionNumber":"AD/B737/348","sectionType":"part","heading":"AD/B737/348","content":"## AD/B737/348","sortOrder":1},{"sectionNumber":"AN-26 Insulation Blankets","sectionType":"part","heading":"AN-26 Insulation Blankets","content":"## AN-26 Insulation Blankets","sortOrder":2},{"sectionNumber":"1/2009","sectionType":"part","heading":"1/2009","content":"## 1/2009","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with a clear, focused scope: addressing a specific fire safety defect in specific aircraft models. The scope remains tightly constrained to the AN-26 insulation blanket issue as originally identified."},"complexity_factors":["Multiple compliance pathways (Option A vs Option B) with different approval requirements","Cross-reference to external US regulation (14 CFR 25.856(a)) and FAA approval processes","Specific exception for pre-July 1981 and post-December 1988 manufactured materials based on part-marking","Reference to specific Boeing Service Bulletin (737-25-1572) and its Appendix A for identification methods","Nested conditional logic: main requirement → two alternative compliance methods → exception for non-AN-26 materials → date-based safe harbor for identification","Dual compliance timelines (96 months for replacement, immediate for installation ban)"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of specified Boeing 737 (-200/-200C/-300/-400) to remove or replace flammable Orcon Orcofilm AN‑26 insulation from the pressurised cabin because it promotes rapid fire spread. Compliance may be by installing compliant blankets meeting 14 CFR 25.856(a) or following Boeing SB 737‑25‑1572; proven non‑AN‑26 or certain manufacture‑date blankets are exempt. Installing AN‑26 is banned; work was due within eight years 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"},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"The AD limits action to specified Boeing 737 models/serial numbers (per Boeing Special Attention Service Bulletin 737-25-1572) and to insulation in pressurized fuselage areas, requiring removal/replacement or approved identification and banning reinstallation of AN‑26 unless modified. The instrument's scope, as written, aligns with its stated safety purpose (removal of AN‑26 due to fire propagation risk) and does not indicate any expansion or narrowing beyond that objective."},"complexity_factors":["Applicability tied to specific serial numbers defined in Boeing Special Attention Service Bulletin 737-25-1572 (Applicability) — requires cross-referencing the service bulletin to determine affected aircraft.","Two alternative compliance routes (Requirement 1a or 1b) — either FAA‑approved replacement method (Manager, Seattle ACO) with 14 CFR 25.856(a) compliance, or removal/install per Boeing SB Accomplishment Instructions — increases procedural choice and recordkeeping.","Material identification requirement (Requirement 1 and Note 1) — operators must use an identification method approved by the Manager, Seattle ACO or Appendix A of the Boeing SB to show a blanket is not AN‑26.","Prohibition on installing AN‑26 unless modified to meet 14 CFR 25.856(a) (Requirement 2) — creates ongoing material‑control and procurement constraints for operators and MROs.","Long compliance window (Compliance 1: within 96 months) — allows planning but spreads cost and scheduling impacts over years and requires long‑term tracking.","Centralised regulatory discretion (approval by Manager, Seattle ACO specified in Requirement 1a and identification method approvals) — introduces case‑by‑case FAA decisions.","Use of part‑mark dates for positive exclusion (Note 1: manufactured before July 1981 or after December 1988 not AN‑26) — requires inspection of markings, which may be unclear or degraded.","Cross‑references to other regulatory instruments (14 CFR 25.856(a); FAA AD 2008-23-09 referenced in Note 2) — obliges operators to consult additional standards and directives."],"plain_english_summary":"This directive requires operators of specified Boeing 737-200/200C/300/400 aircraft to remove and replace fuselage insulation blankets made of Orcon Orcofilm AN‑26 (or demonstrate the material is not AN‑26) using FAA‑approved methods within 96 months, and it forbids installing AN‑26 unless modified to meet 14 CFR 25.856(a). The AD states AN‑26 can ignite and propagate fire after electrical arcing, so the measure mechanically removes or replaces the material and imposes approved identification and modification steps."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-348-an-26-insulation-blankets","history":"/api/acts/ad-b737-348-an-26-insulation-blankets/history","analysis":"/api/acts/ad-b737-348-an-26-insulation-blankets/analysis","conflicts":"/api/acts/ad-b737-348-an-26-insulation-blankets/conflicts","importantCases":"/api/acts/ad-b737-348-an-26-insulation-blankets/important-cases","documents":"/api/acts/ad-b737-348-an-26-insulation-blankets/documents"}}