{"id":"F2006B03050","name":"AD/B747/149 - Fuselage Skin Above Forward Entry Doors","slug":"ad-b747-149-fuselage-skin-above-forward-entry-doors","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42409,"registerId":"commonwealth-F2006B03050-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/149 - Fuselage Skin Above Forward Entry Doors","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nBoeing 747 Series Aeroplanes\n\nAD/B747/149 Fuselage Skin Above Forward Entry Doors 7/95\n\nApplicability: B747 aircraft, line numbers 1 to 206 inclusive.\n\nRequirement: 1. Inspect the fuselage skin at the aft row of fasteners between stringers S-14E and S- 16 at the left and right Body Station (BS) 460 circumferential splice for cracks.\n\nInspect, using the high frequency eddy current (HFEC) method, in accordance with Boeing Service Bulletin (SB) 747-53-2289, Revision 2.\n\nFor aircraft which have not been modified in accordance with Boeing SB 747-53- 2181 or SB 747-53-2105, do an additional HFEC inspection of the forward row of fasteners of the BS 460 circumferential splice. Inspect in accordance with Boeing SB 747-53-2289, Revision 2.\n\n2. Modify the aft side of the left hand and right hand lap splices between stringers 14E and 16 in accordance with Boeing SB 747-53-2289 Revision 2. If not already accomplished, modify the forward side of the left hand and right hand lap splices between stringers 14E and 16 in accordance with either Boeing SB 747-53-2181 or 747-53-2105.\n\nNote: FAA AD 89-21-09 refers.\n\nCompliance: 1. Inspect before 10 000 flights or before 1000 flights after 22 June 1995, whichever occurs last.\n\nRe-inspect at intervals not to exceed 3000 flights.\n\n2. Modify before 20 000 flights.\n\nModification in accordance with Requirement 2 cancels the inspection requirements of this Directive.\n\nBackground: Operators have reported numerous skin cracks up to 15 inches long at the rear fastener row of the BS 460 circumferential skin splice. If allowed to remain un- repaired the cracking could result in a rapid decompression.\n\nThe requirements of this AD are in accordance with the Boeing 747 Structures Working Group recommendations.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete airworthiness directive addressing a specific structural defect in a defined aircraft population. It has not expanded beyond its original technical safety purpose."},"complexity_factors":["Technical aviation terminology throughout (stringers, lap splices, Body Station references, eddy current inspection methods)","Multiple cross-references to Boeing Service Bulletins (SB 747-53-2289, SB 747-53-2181, SB 747-53-2105) and FAA AD 89-21-09 — compliance requires obtaining external technical documents","Conditional logic: different inspection requirements apply depending on whether prior modifications have been made","Dual compliance timelines (flights-based deadlines with 'whichever occurs last' calculation)","Cancellation clause: modification requirement voids inspection requirement — creates interdependency between sections"],"plain_english_summary":"This safety order targets early-model Boeing 747s (serials 1–206) after discovery of long cracks in the fuselage skin above forward entry doors that could cause rapid cabin decompression. It requires mandatory periodic inspections using crack-detection techniques and ultimately structural repair to restore safety.\n\nIt affects owners, operators, and maintenance crews of those aircraft and is issued under aviation safety powers; failure to comply risks grounding the planes."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The directive applies to B747 line numbers 1–206 and prescribes inspections and modifications to the BS 460 circumferential splice to address reported cracking. The text does not indicate any change from an earlier or original scope; it sets inspection and modification requirements and associated compliance timelines."},"complexity_factors":["Limited applicability to specific airframes (B747 line numbers 1–206) (Applicability).","Requires a specific non-destructive test method (HFEC) and compliance with Boeing Service Bulletin 747-53-2289 Rev 2 (Requirement 1).","Conditional additional inspection depending on whether aircraft were modified under SB 747-53-2181 or SB 747-53-2105 (Requirement 1).","Mandated structural modification per SB 747-53-2289 Rev 2 and alternative SB references for forward splice modification (Requirement 2).","Compliance timing: initial inspection windows, recurring 3,000-flight intervals, and a 20,000-flight deadline for modification; modification cancels inspection obligations (Compliance).","Safety-critical consequence (risk of rapid decompression) driving mandatory action (Background).","Dependence on external documents (multiple Boeing SBs and referenced FAA AD) for procedural detail and acceptance (Requirement/Note).","Operational cost and scheduling burden falls on operators; requires specialised equipment and trained personnel (implied by HFEC and SB compliance)."],"plain_english_summary":"This airworthiness directive requires operators of Boeing 747 aircraft (line numbers 1–206) to inspect the fuselage skin at the BS 460 circumferential splice using high-frequency eddy current (HFEC) methods and to modify the lap splices per Boeing service bulletins. Inspections must be done before specified flight counts and repeated at set intervals; completing the mandated modification removes the inspection requirement. The directive responds to reported skin cracking that could cause rapid decompression. Operators pay for and schedule the inspections and modifications."},"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-b747-149-fuselage-skin-above-forward-entry-doors","history":"/api/acts/ad-b747-149-fuselage-skin-above-forward-entry-doors/history","analysis":"/api/acts/ad-b747-149-fuselage-skin-above-forward-entry-doors/analysis","conflicts":"/api/acts/ad-b747-149-fuselage-skin-above-forward-entry-doors/conflicts","importantCases":"/api/acts/ad-b747-149-fuselage-skin-above-forward-entry-doors/important-cases","documents":"/api/acts/ad-b747-149-fuselage-skin-above-forward-entry-doors/documents"}}