{"id":"F2009L03784","name":"AD/B747/397 - Fuselage Section 41 Frames","slug":"ad-b747-397-fuselage-section-41-frames","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":141668,"registerId":"commonwealth-F2009L03784-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Boeing 747 Series Aeroplanes","sectionType":"division","heading":"Boeing 747 Series Aeroplanes","content":"### Boeing 747 Series Aeroplanes\n\n| AD/B747/397 | Fuselage Section 41 Frames | 12/2009 |\n| ----------- | -------------------------- | ------- |\n\n| Applicability: | Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, 747SR and 747SP series aircraft, as identified in Boeing Alert Service Bulletin 747-53A2732 original issue, or later FAA approved revision.Model 747-400, -400D and -400F series aircraft, as identified in Boeing Alert Service Bulletin 747-53A2753 original issue, or later FAA approved revision. |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with the technical requirements of FAA AD 2009-19-05 Amdt 39-16022.                                                                                                                                                                                                                                                                          |\n| Compliance:    | As specified in the Requirement document, with a revised effective date of19 November 2009.                                                                                                                                                                                                                                                                       |\n|                | This Airworthiness Directive becomes effective on 19 November 2009.                                                                                                                                                                                                                                                                                               |\n| Background:    | The FAA received reports of cracking in fuselage frames made of 2024 aluminium alloy that were installed during previous modification of the frames in Section 41 and during production. Such cracking, unless detected and corrected, could result in cracking of the adjacent fuselage skin and consequent rapid decompression of the aircraft.                 |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n30 September 2009","sortOrder":0},{"sectionNumber":"AD/B747/397","sectionType":"part","heading":"AD/B747/397","content":"## AD/B747/397","sortOrder":1},{"sectionNumber":"Fuselage Section 41 Frames","sectionType":"part","heading":"Fuselage Section 41 Frames","content":"## Fuselage Section 41 Frames","sortOrder":2},{"sectionNumber":"12/2009","sectionType":"part","heading":"12/2009","content":"## 12/2009","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"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The directive adopts and enforces the technical requirements of FAA AD 2009-19-05 for the identified 747 models and references the Boeing Alert Service Bulletins; it does not indicate any expansion or narrowing of applicability beyond those referenced documents and sets an effective date of 19 November 2009 (Requirement; Applicability; Compliance)."},"complexity_factors":["Cross-references to external mandatory documents: compliance is defined by FAA AD 2009-19-05 and Boeing Alert Service Bulletins (Requirement; Applicability), requiring operators to consult and follow those texts.","Multiple aircraft variants listed (Applicability) — determining applicability for a given airframe requires checking model and bulletin identification.","Technical inspection and repair work: detecting and fixing cracks in 2024 aluminium-alloy frames requires specialist maintenance skills, non-routine access and tooling (Background; Requirement).","Allowance for later FAA-approved revisions (Applicability) introduces version-control and compliance-timing questions about which revision applies.","Safety-critical timing and effective date: the AD sets an effective date (Compliance) that creates operational scheduling and potential urgent-work pressures.","Operational costs and downtime for operators implied by mandated inspections/repairs (Requirement; Background)."],"plain_english_summary":"This airworthiness directive requires operators of specified Boeing 747 variants to carry out inspections and any needed repairs on Section 41 fuselage frames in line with FAA AD 2009‑19‑05 and the referenced Boeing Alert Service Bulletins. It targets cracking in 2024‑alloy frames that, if undetected, could lead to adjacent skin failure and rapid decompression, and becomes effective 19 November 2009."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a standard, narrow airworthiness directive focused on a specific structural defect in a defined aircraft type. It has not expanded beyond its original safety purpose."},"complexity_factors":["Short, single-purpose document (approximately 250 words)","Only 2 defined technical references (FAA AD 2009-19-05 and Boeing Service Bulletins 747-53A2732/747-53A2753)","Simple conditional applicability based on aircraft model and modification history","No nested exceptions or complex procedural logic","Clear compliance date and single effective date","Heavy reliance on external technical documents (incorporated by reference) rather than detailed internal provisions"],"plain_english_summary":"This Airworthiness Directive orders operators of certain older Boeing 747 variants (‑100/‑200/‑300/‑400, 747SR, 747SP) whose Section 41 frames were modified or built with 2024 aluminium to inspect and repair cracking in the nose-area frames. \n\nCracks can spread to the skin and cause rapid decompression, so the AD mandates following the FAA’s AD 2009‑19‑05 and Boeing service bulletins for required inspections and repairs; it took effect 19 November 2009."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-397-fuselage-section-41-frames","history":"/api/acts/ad-b747-397-fuselage-section-41-frames/history","analysis":"/api/acts/ad-b747-397-fuselage-section-41-frames/analysis","conflicts":"/api/acts/ad-b747-397-fuselage-section-41-frames/conflicts","importantCases":"/api/acts/ad-b747-397-fuselage-section-41-frames/important-cases","documents":"/api/acts/ad-b747-397-fuselage-section-41-frames/documents"}}