{"id":"F2008L00595","name":"AD/B747/372 - Engine Core Cowl Flipper Doors","slug":"ad-b747-372-engine-core-cowl-flipper-doors","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":119566,"registerId":"commonwealth-F2008L00595-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/B747/372 | Engine Core Cowl Flipper Doors | 3/2008 |\n| ----------- | ------------------------------ | ------ |\n\n| Applicability: | Model 747-200B, -300, -400, -400D, and -400F series aircraft, equipped with General Electric CF6-80C2 engines.                                                                                                                                                                                                                                                                                                                                        |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with the technical requirements of FAA AD 2007-26-07 Amdt 39-15309.Note: Boeing Special Attention Service Bulletin 747-71-2310 original issue, and Rohr Service Bulletin TBC/80C2-NAC-71-035 original issue, or later FAA approved revisions, refer.                                                                                                                                                                             |\n| Compliance:    | As specified in the Requirement document, with a revised effective date of13 March 2008.                                                                                                                                                                                                                                                                                                                                                              |\n|                | This Airworthiness Directive becomes effective on 13 March 2008.                                                                                                                                                                                                                                                                                                                                                                                      |\n| Background:    | The FAA received two reports of missing flipper doors for the engine core cowls. Migrated hinge pins and damaged flipper doors, unless detected and corrected, could allow the flipper door to fall off. This could allow an engine fire to propagate into the flammable leakage zone of the strut and for the amount of fire extinguishing agent reaching the fire to be diluted. The result could be an uncontained fire in the engine compartment. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n30 January 2008","sortOrder":0},{"sectionNumber":"AD/B747/372","sectionType":"part","heading":"AD/B747/372","content":"## AD/B747/372","sortOrder":1},{"sectionNumber":"Engine Core Cowl Flipper Doors","sectionType":"part","heading":"Engine Core Cowl Flipper Doors","content":"## Engine Core Cowl Flipper Doors","sortOrder":2},{"sectionNumber":"3/2008","sectionType":"part","heading":"3/2008","content":"## 3/2008","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The directive adopts the FAA AD and referenced service bulletins for the listed 747 models with CF6‑80C2 engines; the supplied text shows no expansion or narrowing of scope beyond those documents and the named aircraft/engine combination ('Applicability' and 'Requirement')."},"complexity_factors":["Cross-reference to external FAA AD 2007-26-07 creates dependence on another jurisdiction's written requirements ('Requirement').","Permits use of original or later FAA‑approved revisions of Boeing and Rohr service bulletins, introducing ongoing content updates and potential version ambiguity ('Requirement').","Technical inspection and corrective-action work requires specialised maintenance skills, parts and possible aircraft downtime (implied by nature of action in 'Requirement' and 'Applicability').","Applicability is limited to specific 747 models with CF6‑80C2 engines, so fleet applicability is narrow but concentrated on operators of those variants ('Applicability').","Compliance timing and revised effective date are specified but rely on the external Requirement document for exact compliance windows ('Compliance').","Safety-critical consequence linkage is direct: mechanical defect → possible fire propagation → reduced extinguishing effectiveness, so enforcement and accurate execution carry operational risk ('Background')."],"plain_english_summary":"This directive requires operators of Boeing 747-200B, -300, -400, -400D and -400F aircraft with General Electric CF6‑80C2 engines to carry out the inspections and repairs specified in FAA AD 2007‑26‑07 and referenced Boeing/Rohr service bulletins. It addresses reports of migrated hinge pins and damaged engine core cowl flipper doors that could detach and allow engine fire to spread into the strut leakage zone, reducing fire‑extinguishing effectiveness and risking an uncontained engine compartment fire."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive addressing a specific mechanical defect on specific aircraft. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (approximately 200 words of substantive content)","Only 1 defined term implicitly referenced (the AD number itself)","No nested conditional logic or exceptions","Single cross-reference to an external FAA directive and two service bulletins","Straightforward applicability criteria (specific aircraft models and engine types)","Clear, single compliance date with no phased or conditional implementation"],"plain_english_summary":"This AD orders operators of certain Boeing 747-200B/300/400/-400D/-400F aircraft with GE CF6-80C2 engines to inspect and repair engine core cowl \"flipper doors\" and hinge pins after two incidents where pins migrated and doors were lost. A detached door can cause engine fire propagation and reduce fire-extinguishing effectiveness.\n\nIt implements FAA AD 2007-26-07 and related Boeing/Rohr service bulletins; it affects airlines and operators of the specified airplane/engine combination and addresses a critical fire-safety hazard."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-372-engine-core-cowl-flipper-doors","history":"/api/acts/ad-b747-372-engine-core-cowl-flipper-doors/history","analysis":"/api/acts/ad-b747-372-engine-core-cowl-flipper-doors/analysis","conflicts":"/api/acts/ad-b747-372-engine-core-cowl-flipper-doors/conflicts","importantCases":"/api/acts/ad-b747-372-engine-core-cowl-flipper-doors/important-cases","documents":"/api/acts/ad-b747-372-engine-core-cowl-flipper-doors/documents"}}