{"id":"F2006B03084","name":"AD/B747/183 - Nacelle Strut Structure","slug":"ad-b747-183-nacelle-strut-structure","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42443,"registerId":"commonwealth-F2006B03084-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/183 - Nacelle Strut Structure","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/B747/183 Nacelle Strut Structure 8/98\n\nApplicability: Model 747-100, -200, and -300 aircraft having line positions 1 through 886; excluding aircraft on which the wing/strut modification (FAA AD 95-13-07) has been accomplished; and excluding aircraft designated as Group 5 in Boeing Alert Service Bulletin 747-54A2179 Revision 2.\n\nRequirement: Action in accordance with the technical requirements of FAA AD 98-08-15 Amendment 39-10464.\n\nNote: Boeing Alert Service Bulletin 747-54A2179 Revision 2 refers.\n\nCompliance: As specified in the Requirement document with a revised effective date of 16 July 1998 for the initial and repeat inspection requirements.\n\nThis airworthiness directive becomes effective on 16 July 1998.\n\nBackground: The FAA received several reports of cracking of the vertical chords, midspar webs, and canted closure webs on the inboard and outboard struts of certain Model 747 series aircraft. Investigation has revealed that the cracking was due to fatigue and stress corrosion. Additionally, the investigation revealed that the cracking in the midspar webs was due to fatigue. Such fatigue cracking and stress corrosion, if not corrected, could result in failure of the strut-to-wing interface, and consequent separation of the engine and strut from the aircraft.","sortOrder":0}],"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":false,"description":"The directive adopts the FAA AD requirements for affected 747-100/200/300 line positions and sets a revised effective date and specified exclusions. It does not broaden applicability beyond the FAA-mandated population; it aligns Australian requirements with the FAA/Boeing technical documents while excluding aircraft already modified or in Boeing's Group 5."},"complexity_factors":["Cross-reference to FAA AD 98-08-15 and Boeing Alert Service Bulletin 747-54A2179 Rev 2 — requires operators to follow external technical documents.","Technical inspection and repair tasks for fatigue and stress-corrosion in multiple structural elements (vertical chords, midspar webs, canted closure webs).","Conditional applicability and explicit exclusions (aircraft with FAA AD 95-13-07 modification and Boeing Group 5) requiring fleet-specific determinations.","Repeat inspection scheduling and a revised effective date (16 July 1998) introducing timing/compliance management.","Safety-critical potential consequence (engine and strut separation) raising urgency and likely tighter regulatory oversight.","Operational and cost burden falls on aircraft operators/owners to perform inspections, recordkeeping, and any repairs."],"plain_english_summary":"This airworthiness directive requires operators of certain Boeing 747-100/200/300 (line positions 1–886) to carry out the inspections and corrective actions set out in FAA AD 98-08-15 and Boeing Alert Service Bulletin 747-54A2179 Rev 2, effective 16 July 1998. It excludes aircraft with the wing/strut modification mandated by FAA AD 95-13-07 and those designated Group 5. The measure responds to identified fatigue and stress-corrosion cracking in nacelle strut components; operators must fund and schedule inspections and repairs per the AD."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This airworthiness directive maintains its original narrow scope — addressing a specific structural fatigue issue in defined Boeing 747 models. The exclusions and applicability criteria are precisely tailored to the safety risk identified, with no evidence of scope creep beyond the original safety purpose."},"complexity_factors":["Single specific technical requirement (comply with external FAA directive)","Three applicability criteria with two explicit exclusions","One defined external reference (Boeing Alert Service Bulletin 747-54A2179 Revision 2)","No nested conditional logic or internal cross-references","Short, self-contained document (approximately 200 words)"],"plain_english_summary":"This FAA safety order requires owners/operators of Boeing 747‑100/200/300 aircraft (serial numbers 1–886, excluding certain modified and Group 5 airplanes) to inspect and repair nacelle strut structures per FAA AD 98‑08‑15. It responds to metal‑fatigue and stress‑corrosion cracks that could allow an engine and strut to detach in flight. Initial and repeat inspections must begin by 16 July 1998 and follow the FAA’s specified technical procedures."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-183-nacelle-strut-structure","history":"/api/acts/ad-b747-183-nacelle-strut-structure/history","analysis":"/api/acts/ad-b747-183-nacelle-strut-structure/analysis","conflicts":"/api/acts/ad-b747-183-nacelle-strut-structure/conflicts","importantCases":"/api/acts/ad-b747-183-nacelle-strut-structure/important-cases","documents":"/api/acts/ad-b747-183-nacelle-strut-structure/documents"}}