{"id":"F2006B03139","name":"AD/B747/240 - Air Conditioning Duct Insulation","slug":"ad-b747-240-air-conditioning-duct-insulation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42511,"registerId":"commonwealth-F2006B03139-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS 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 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 747 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/B747/240 Air Conditioning Duct Insula","sectionType":"part","heading":"AD/B747/240 Air Conditioning Duct Insulation 4/2001","content":"# AD/B747/240 Air Conditioning Duct Insulation 4/2001\n\nApplicability: Model 747 series aircraft having the line numbers listed in the requirement document.\n\nRequirement: Rework duct assemblies or replace existing duct assemblies with new or reworked items in accordance with the technical requirements of FAA AD 2000-26-05 Amdt 39-12055.\n\nCompliance: Before 19 April 2007.\n\nThis Airworthiness Directive becomes effective on 19 April 2001.\n\nBackground: An FAA AD has been raised to prevent potential ignition of fibreglass insulation material installed on the outside of the Environmental control system (ECS) ducts, which could propagate a small fire and lead to a larger fire.\n\n![Signature of David Villiers, Delegate of the Civil Aviation Safety Authority.](image.002.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 5 March 2001\n\n![](image.001.png)","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD adopts the FAA AD's technical requirements for specified Boeing 747 line numbers without expanding applicability or adding obligations beyond reworking or replacing ECS duct assemblies per the FAA instruction (Requirement; Applicability). The instrument limits scope to aircraft listed in the requirement document and to the specified corrective actions, with the stated purpose of preventing ignition/propagation of fire from external fibreglass insulation (Background)."},"complexity_factors":["Cross-reference to an external FAA AD (Requirement: 'in accordance with the technical requirements of FAA AD 2000-26-05 Amdt 39-12055') — requires users to consult and follow a separate foreign regulatory document.","Applicability is determined by listed line numbers (Applicability: 'Model 747 series aircraft having the line numbers listed in the requirement document') — affected fleet identification requires checking the requirement document.","Technical compliance (rework or replacement of duct assemblies) involves specialised maintenance, parts and downtime (Requirement: 'Rework duct assemblies or replace existing duct assemblies with new or reworked items').","Fixed compliance deadline creates scheduling pressure for operators (Compliance: 'Before 19 April 2007').","Legal basis and issuance by CASA delegate (preamble: 'issues the following Airworthiness Directive ... under subregulation 39.1 (1) of CAR 1998'; signature block) — indicates executive regulatory action rather than new primary legislation.","Instrument is concise and delegates detailed procedural and technical instructions to the FAA AD (Requirement points to FAA text) — increases reliance on external technical material and may complicate verification and enforcement."],"plain_english_summary":"This AD requires operators of specified Boeing 747 line-number aircraft to rework or replace air‑conditioning (ECS) duct insulation in accordance with FAA AD 2000‑26‑05, to be completed before 19 April 2007. It became effective 19 April 2001.\n\nCASA (through its delegate) mandates the work; aircraft operators bear the cost and must schedule maintenance. The stated safety objective is to prevent ignition and fire propagation of external fibreglass insulation on ECS ducts."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with a narrow, specific safety purpose: addressing fire risk from duct insulation. The scope matches the original intent of correcting an unsafe condition in aviation safety."},"complexity_factors":["Very short document (under 300 words)","Only 4 defined structural sections (Applicability, Requirement, Compliance, Background)","Single cross-reference to external FAA technical document","No nested conditions or exceptions","Clear, unambiguous compliance deadline","Simple binary applicability (specific line numbers in attached document)"],"plain_english_summary":"This is a safety order for Boeing 747 aircraft. It requires airlines and aircraft operators to fix or replace the insulation around air conditioning ducts on specific Boeing 747 planes. The insulation is made of fibreglass and could catch fire, potentially turning a small fire into a bigger one. Operators must follow the technical instructions from the US Federal Aviation Administration (FAA) and complete the work before April 2007. The directive took effect in April 2001."},"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-b747-240-air-conditioning-duct-insulation","history":"/api/acts/ad-b747-240-air-conditioning-duct-insulation/history","analysis":"/api/acts/ad-b747-240-air-conditioning-duct-insulation/analysis","conflicts":"/api/acts/ad-b747-240-air-conditioning-duct-insulation/conflicts","importantCases":"/api/acts/ad-b747-240-air-conditioning-duct-insulation/important-cases","documents":"/api/acts/ad-b747-240-air-conditioning-duct-insulation/documents"}}