{"id":"F2006B03096","name":"AD/B747/195 - Leading Edge Flaps - Prevention of Uncommanded Retraction","slug":"ad-b747-195-leading-edge-flaps-prevention-of-uncommanded-retraction","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42468,"registerId":"commonwealth-F2006B03096-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/195 - Leading Edge Flaps - Prevention of Uncommanded Retraction","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/B747/195 Leading Edge Flaps \\- Prevention of Uncommanded Retraction\n\n  \n2/99\n\nApplicability: Model 747-400 series aeroplanes, having cumulative line number (C/L) 696 through 1090 inclusive.\n\nRequirement: 1. For Groups 1 and 2 aircraft as identified in Boeing Service Bulletin 747-27A2356, Revision 1, dated 13 August 1998, replace the cam assembly, cam bellcrank assembly and thrust reverser control switch actuator on all four thrust levers with new components in accordance with the reference Boeing Service Bulletin.\n\n2. For Groups 3 and 4 aircraft as identified in Boeing Service Bulletin 747-27A2356, Revision 1, dated 13 August 1998, replace the cam bellcrank assembly and thrust reverser control switch actuator on all four thrust levers with new components in accordance with the reference Boeing Service Bulletin..\n\nNote: FAA AD 98-24-26 amendment 39-10913 refers.\n\nCompliance: Unless already accomplished, within 18 months of the effective date of this Directive.\n\nThis Airworthiness Directive becomes effective on 25 February 1999.\n\nBackground: This Directive is issued to mandate actions deemed necessary to prevent the uncommanded automatic retraction of the leading edge flaps during take-off which would seriously degrade lift off and climb capabilities and could result in near stall conditions.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope: mandating specific hardware replacements on a limited subset of Boeing 747-400 aircraft to address a defined safety hazard. There is no evidence of scope creep; the directive targets exactly the problem described in the background (uncommanded leading edge flap retraction) and applies only to the specific aircraft serial numbers affected."},"complexity_factors":["Very short document (under 300 words)","Only 4 defined groupings (Groups 1-4 referenced from external Boeing Service Bulletin)","Single cross-reference to FAA AD 98-24-26 and Boeing Service Bulletin 747-27A2356","Simple conditional structure: two distinct requirements based on aircraft grouping","Clear, single compliance deadline (18 months from effective date)","No nested exceptions or complex logical operators","Technical aviation terminology is present but used precisely for a specialist audience (aircraft maintenance engineers and operators)"],"plain_english_summary":"CASA requires operators of Boeing 747‑400 aircraft (line numbers 696–1090) to replace the cam assembly, cam bellcrank assembly and thrust reverser control switch actuator in cockpit thrust levers. \n\nThese mandated repairs, to be completed within 18 months of 25 Feb 1999 (by Aug 2000) unless already done, prevent uncommanded leading‑edge flap retraction during take‑off that could cause serious loss of lift, difficulty becoming airborne and a stall."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The Directive's scope aligns with its stated purpose: it targets a defined subset of 747-400 aeroplanes and mandates specific component replacements to prevent uncommanded leading edge flap retraction. It does not broaden applicability or introduce additional obligations beyond the parts replacements, timing, and Service Bulletin compliance specified (Applicability; Requirement; Background)."},"complexity_factors":["Targeted applicability (specific to Model 747-400 C/L 696–1090) reduces scope and legal complexity (Applicability).","Differing part requirements by group: Groups 1&2 require cam assembly, cam bellcrank and switch actuator; Groups 3&4 require cam bellcrank and switch actuator — adds operational classification work for operators (Requirement 1 & Requirement 2).","Mandated compliance to an external technical document (Boeing Service Bulletin 747-27A2356 Revision 1) means implementation depends on that SB's procedures and parts lists (Requirement 1 & 2).","Fixed compliance window of 18 months creates scheduling and fleet-availability costs for operators (Compliance).","Affects all four thrust levers on each aeroplane, so per-aircraft parts and labour costs are non-trivial even though procedure is limited in scope (Requirement 1 & 2).","Cross-reference to FAA AD reduces interpretive uncertainty but links compliance to parallel foreign regulatory action (Note).","Directive prescribes mandatory hardware changes with little regulatory discretion; operators' primary decisions are scheduling, parts sourcing and installation (Requirement).","Potential implementation risks: parts availability, maintenance downtime and need for appropriately qualified personnel to perform replacements (implied by Requirement and Service Bulletin reference)."],"plain_english_summary":"This Airworthiness Directive requires operators of certain Boeing 747-400 aeroplanes (cumulative line numbers 696–1090) to replace specified cam, cam bellcrank and thrust reverser control switch actuator components on all four thrust levers in accordance with Boeing Service Bulletin 747-27A2356 Revision 1. The stated purpose is to prevent uncommanded automatic retraction of the leading edge flaps during take-off, which the Directive says can seriously degrade lift and approach near-stall conditions; operators must complete the work within 18 months."},"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-b747-195-leading-edge-flaps-prevention-of-uncommanded-retraction","history":"/api/acts/ad-b747-195-leading-edge-flaps-prevention-of-uncommanded-retraction/history","analysis":"/api/acts/ad-b747-195-leading-edge-flaps-prevention-of-uncommanded-retraction/analysis","conflicts":"/api/acts/ad-b747-195-leading-edge-flaps-prevention-of-uncommanded-retraction/conflicts","importantCases":"/api/acts/ad-b747-195-leading-edge-flaps-prevention-of-uncommanded-retraction/important-cases","documents":"/api/acts/ad-b747-195-leading-edge-flaps-prevention-of-uncommanded-retraction/documents"}}