{"id":"F2006L03847","name":"AD/B747/352 - Overlapped Skin Panels in the Fuselage Skin Lap Joints","slug":"ad-b747-352-overlapped-skin-panels-in-the-fuselage-skin-lap-joints","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":137729,"registerId":"commonwealth-F2006L03847-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/B747/352 | Overlapped Skin Panels in theFuselage Skin Lap Joints | 13/2006 |\n| ----------- | ----------------------------------------------------- | ------- |\n\n| Applicability: | Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, -400, -400D, -400F, 747SR, and 747SP aircraft; as identified in Boeing Alert Service Bulletin747-53A2501 original issue, dated 24 March 2005, or later FAA approved revision.                                                                                      |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Action in accordance with the technical requirements of FAA AD 2006-22-09 Amdt 39-14806.                                                                                                                                                                                                                                       |\n| Compliance:    | As specified in the Requirement document, with a revised effective date of21 December 2006.                                                                                                                                                                                                                                    |\n|                | This Airworthiness Directive becomes effective on 21 December 2006.                                                                                                                                                                                                                                                            |\n| Background:    | The FAA received a report indicating that an operator found multiple small cracks in the overlapped skin panels in the fuselage skin lap joints. Such cracking, unless detected and corrected, could join together and result in reduced structural capability in the skin and consequent rapid decompression of the aircraft. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n8 November 2006","sortOrder":0},{"sectionNumber":"AD/B747/352","sectionType":"part","heading":"AD/B747/352","content":"## AD/B747/352","sortOrder":1},{"sectionNumber":"Overlapped Skin Panels in theFuselage Sk","sectionType":"part","heading":"Overlapped Skin Panels in theFuselage Skin Lap Joints","content":"## Overlapped Skin Panels in the  \nFuselage Skin Lap Joints","sortOrder":2},{"sectionNumber":"13/2006","sectionType":"part","heading":"13/2006","content":"## 13/2006","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow airworthiness directive addressing a specific structural defect in specific aircraft models. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (under 300 words)","Only 1 defined term implicitly referenced (FAA AD 2006-22-09)","No conditional logic or nested exceptions — simple directive structure","Single compliance pathway: follow the referenced FAA document","No cross-references to other Australian legislation","Clear applicability table with specific aircraft models listed"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of specified Boeing 747 models to inspect and repair cracks in overlapped fuselage skin lap joints, following FAA AD 2006-22-09 and Boeing’s service bulletin. Unrepaired cracking can propagate and lead to rapid decompression. Compliance was required by 21 December 2006."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The instrument sticks to its original safety-focused scope: to require inspection and correction of cracks in overlapped fuselage skin lap joints for the specified Boeing 747 models per the referenced FAA AD and Boeing service bulletin. The text contains no provision extending the types of action or the population beyond that stated safety objective."},"complexity_factors":["Cross-reference to external documents: Requirement directs action 'in accordance with FAA AD 2006-22-09' and a Boeing Alert Service Bulletin (adds dependency on non‑text materials).","Technical content: Inspections and repairs concern structural skin lap joints and crack growth—requires specialised engineering assessment and maintenance skills.","Applicability breadth: Multiple 747 variants listed (Model 747-100 through -400F, 747SR, 747SP), increasing the number of affected operators and fleet configurations.","Compliance timing and enforceability: Effective date specified (21 December 2006); creates a hard deadline for operators to implement actions.","Implementation burden on operators: Costs and downtime for inspections/repairs are borne by aircraft operators; scheduling across commercial operations is required.","Regulatory delegation: Issued by CASA delegate but performance standard set by FAA AD—limits domestic regulatory discretion on technical content."],"plain_english_summary":"**This Airworthiness Directive requires operators of specified Boeing 747 models to inspect and, if necessary, repair overlapped fuselage skin lap joints in accordance with FAA AD 2006-22-09 and Boeing Alert Service Bulletin 747‑53A2501.** The Civil Aviation Safety Authority (via its delegate) mandates compliance from 21 December 2006; operators pay for inspections and any repairs. The requirement responds to reported small cracks that, if undetected, could join and reduce skin strength causing rapid decompression."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-352-overlapped-skin-panels-in-the-fuselage-skin-lap-joints","history":"/api/acts/ad-b747-352-overlapped-skin-panels-in-the-fuselage-skin-lap-joints/history","analysis":"/api/acts/ad-b747-352-overlapped-skin-panels-in-the-fuselage-skin-lap-joints/analysis","conflicts":"/api/acts/ad-b747-352-overlapped-skin-panels-in-the-fuselage-skin-lap-joints/conflicts","importantCases":"/api/acts/ad-b747-352-overlapped-skin-panels-in-the-fuselage-skin-lap-joints/important-cases","documents":"/api/acts/ad-b747-352-overlapped-skin-panels-in-the-fuselage-skin-lap-joints/documents"}}