{"id":"F2008L04311","name":"AD/B737/249 Amdt 1 - Forward Lower Lobe Fuselage Skin","slug":"ad-b737-249-amdt-1-forward-lower-lobe-fuselage-skin","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":76301,"registerId":"commonwealth-F2008L04311-current","compilationNumber":null,"startDate":"2026-04-02","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/B737/249 Amdt 1 | Forward Lower Lobe Fuselage Skin | 1/2009 DM |\n| ------------------ | -------------------------------- | --------- |\n\n| Applicability: | Model 737-100, -200, -200C, -300, -400, and -500 series aircraft; as identified in Boeing Special Attention Service Bulletin 737-53-1230, dated 13 June 2002, or later FAA approved revision.                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with the technical requirements of FAA AD 2005-19-25 Amdt 39-14290.Note: Boeing Service Bulletin 737-53-1117 Revision 1, or later FAA approved revision, refers.Corrective actions (repairs or repeat inspections) that are approved on an FAA form 8100-9 and approved by the Manager, Seattle Aircraft Certification Office or delegate as an Alternative Method of Compliance (AMOC) to the requirements of FAA AD 2005-19-25, may be carried out without the need to obtain an exclusion from CASA from this airworthiness directive.                                                                  |\n| Compliance:    | As specified in the Requirement document, with a revised effective date of24 November 2005.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |\n|                | This Amendment becomes effective on 14 November 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |\n| Background:    | The FAA received reports of cracks in the fuselage skin of the lower lobe. The actions required by this Directive are intended to detect and correct fatigue cracks of the countersunk rivet holes, which could result in cracks of the fuselage skin of the lower lobe, and consequent rapid depressurisation of the aircraft.This amendment allows the use of an FAA approved Alternative Method of Compliance (AMOC) to the requirements of this AD, without the need for the operator to continually apply for exclusions for the same type of repair. There are no other changes to the technical requirements of this AD. |\n\n|     | The original issue of this AD became effective on 24 November 2005. |\n| --- | ------------------------------------------------------------------- |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n11 November 2008","sortOrder":0},{"sectionNumber":"AD/B737/249 Amdt 1","sectionType":"part","heading":"AD/B737/249 Amdt 1","content":"## AD/B737/249 Amdt 1","sortOrder":1},{"sectionNumber":"Forward Lower Lobe Fuselage Skin","sectionType":"part","heading":"Forward Lower Lobe Fuselage Skin","content":"## Forward Lower Lobe Fuselage Skin","sortOrder":2},{"sectionNumber":"1/2009 DM","sectionType":"part","heading":"1/2009 DM","content":"## 1/2009 DM","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":4,"scope_assessment":{"changed":true,"description":"This amendment does not alter the AD's technical inspection or repair requirements; it changes procedural scope by allowing FAA‑approved AMOCs (on FAA form 8100-9) approved by the Manager, Seattle Aircraft Certification Office (or delegate) to be used without operators having to obtain repeated CASA exclusions. The substantive safety obligations remain as in FAA AD 2005-19-25; the change reduces administrative steps for operators while centralising discretionary AMOC approval with the FAA office."},"complexity_factors":["Cross-reference to external FAA AD (2005-19-25) and Boeing service bulletin for technical requirements, requiring operators to follow non-CASA documents.","Acceptance of FAA‑approved AMOCs (via FAA form 8100-9) shifts procedural interaction from CASA to the FAA Seattle Aircraft Certification Office, creating inter-jurisdictional approval dependencies.","Applicability tied to specific 737 model series as identified in a Boeing service bulletin, so correct identification of affected aircraft is needed.","Compliance burden falls on operators for inspections/repairs and record-keeping; costs and operational downtime are private burdens.","The amendment changes administrative process (AMOC acceptance) but leaves technical inspection and repair requirements unchanged, limiting substantive scope changes.","Effective dates and revised effective dates require attention to timing for implementation and record compliance."],"plain_english_summary":"This amendment requires operators of specified Boeing 737-100 to -500 series aircraft to comply with FAA AD 2005-19-25 for inspection and repair of the forward lower-lobe fuselage skin to detect and correct fatigue cracks that could cause rapid depressurisation. It permits use of FAA‑approved Alternative Methods of Compliance (AMOCs) on FAA form 8100-9, approved by the Seattle Aircraft Certification Office, without repeated CASA exclusion requests; operators bear inspection and repair costs and must follow the FAA-prescribed procedures."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment is purely administrative — it streamlines the process for using FAA-approved alternative repair methods by removing the need for repeated CASA exclusion applications. The technical safety requirements, inspection protocols, and affected aircraft models remain identical to the original 2005 directive. The scope has not expanded beyond the original safety purpose of addressing fatigue cracks in the forward lower lobe fuselage skin."},"complexity_factors":["Heavy reliance on external documents: the directive incorporates by reference FAA AD 2005-19-25 and Boeing Service Bulletin 737-53-1230, meaning the full requirements are not contained in this text","Cross-border regulatory recognition: involves coordination between Australian (CASA) and US (FAA) aviation safety frameworks","Technical aviation terminology throughout (fuselage skin, lower lobe, countersunk rivet holes, AMOC)","Multiple effective dates and amendment tracking (original 2005, amendment 2008)","Specific model applicability with caveats ('as identified in...' limiting clause)"],"plain_english_summary":"This airworthiness directive orders inspections and repairs for fatigue cracks in lower fuselage skin near countersunk rivet holes on certain Boeing 737-100/200/200C/300/400/500 series aircraft to prevent possible rapid depressurisation. It applies to operators covered by the referenced Boeing service bulletin. The amendment doesn’t change technical requirements but lets operators use FAA‑approved alternative repairs (AMOCs) without repeatedly seeking CASA approval, maintaining safety while cutting administrative burden."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-249-amdt-1-forward-lower-lobe-fuselage-skin","history":"/api/acts/ad-b737-249-amdt-1-forward-lower-lobe-fuselage-skin/history","analysis":"/api/acts/ad-b737-249-amdt-1-forward-lower-lobe-fuselage-skin/analysis","conflicts":"/api/acts/ad-b737-249-amdt-1-forward-lower-lobe-fuselage-skin/conflicts","importantCases":"/api/acts/ad-b737-249-amdt-1-forward-lower-lobe-fuselage-skin/important-cases","documents":"/api/acts/ad-b737-249-amdt-1-forward-lower-lobe-fuselage-skin/documents"}}