{"id":"F2009L02681","name":"AD/B747/394 - Thrust Reverser Control System Wiring","slug":"ad-b747-394-thrust-reverser-control-system-wiring","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":79754,"registerId":"commonwealth-F2009L02681-current","compilationNumber":null,"startDate":"2026-04-02","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/B747/394 | Thrust Reverser Control System Wiring | 9/2009 DM |\n| ----------- | ------------------------------------- | --------- |\n\n| Applicability: | Model 747-400 and -400F series aeroplanes, powered by Rolls-Royce RB211 series engines.                                                                                                                                                                                                                                                                                                                                     |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Modify the thrust reverser control system wiring to the flap control unit (FCU) in the P414 and P415 panels in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin (ASB) 747-78A2181, dated 8 June 2009.                                                                                                                                                                                       |\n|                | Later revisions of the above ASB, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2009-13-03, are considered acceptable for compliance with the equivalent Requirements of this Directive.                                                                                                                                                        |\n|                | Note: FAA AD 2009-13-03 Amdt 39-15942 refers.                                                                                                                                                                                                                                                                                                                                                                               |\n| Compliance:    | Within 60 days after the effective date of this Directive.                                                                                                                                                                                                                                                                                                                                                                  |\n|                | This Airworthiness Directive becomes effective on 6 July 2009.                                                                                                                                                                                                                                                                                                                                                              |\n| Background:    | The FAA has received a report of automatic retraction of the leading edge flaps during takeoff due to indications transmitted to the FCU from the thrust reverser control system.This Directive is issued to prevent automatic retraction of the leading edge flaps during takeoff, which could result in reduced climb performance and consequent collision with terrain and obstacles or forced landing of the aeroplane. |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n2 July 2009","sortOrder":0},{"sectionNumber":"AD/B747/394","sectionType":"part","heading":"AD/B747/394","content":"## AD/B747/394","sortOrder":1},{"sectionNumber":"Thrust Reverser Control System Wiring","sectionType":"part","heading":"Thrust Reverser Control System Wiring","content":"## Thrust Reverser Control System Wiring","sortOrder":2},{"sectionNumber":"9/2009 DM","sectionType":"part","heading":"9/2009 DM","content":"## 9/2009 DM","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope: a targeted safety fix for a specific wiring defect in specific aircraft models. It has not expanded beyond its original purpose of preventing flap retraction during takeoff."},"complexity_factors":["Very short document (approximately 250 words)","Only 2 defined technical terms (FCU, AMOC) — both explained in context or self-evident","Single, unambiguous compliance requirement with clear reference to external technical standard (Boeing ASB)","No nested exceptions or conditional logic — one straightforward applicability rule (specific aircraft models and engines)","Single cross-reference to FAA AD for alternative compliance method, clearly marked as optional","Clear deadline with fixed date calculation"],"plain_english_summary":"This mandatory CASA Airworthiness Directive orders operators of Boeing 747-400/747-400F aircraft with Rolls‑Royce RB211 engines to modify wiring in electrical panels P414/P415 per Boeing Alert Service Bulletin 747‑78A2181 within 60 days of 6 July 2009. The fix prevents false thrust‑reverser signals that can cause leading‑edge flaps to retract during takeoff, risking loss of lift and a catastrophic accident."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument's scope aligns with its stated aim: it targets specified 747‑400/-400F RB211-equipped aeroplanes for a wiring modification to prevent leading-edge flap auto-retraction. The text does not expand or narrow applicability beyond that stated, and allows later ASB revisions only if FAA-approved as an AMOC."},"complexity_factors":["Narrow applicability to specific airframe/engine combination reduces administrative breadth (Applicability)","Technical nature of wiring modification to FCU panels P414/P415 requires maintenance capability and parts (Requirement)","Short compliance window increases logistical pressure on operators (Compliance: 60 days)","Acceptance of later ASB revisions only if approved as FAA AMOC introduces inter-agency approval dependency (Requirement / Note)","Safety-critical consequence heightens regulatory priority and verification steps (Background)"],"plain_english_summary":"Requires modification of the thrust-reverser control system wiring to the flap control unit (FCU) in panels P414 and P415 in accordance with Boeing Alert Service Bulletin 747‑78A2181. Applies to Boeing 747‑400 and ‑400F aeroplanes powered by Rolls‑Royce RB211 engines and must be completed within 60 days.\n\nThe directive aims to stop automatic retraction of the leading edge flaps during takeoff — a fault the AD says could reduce climb performance and risk collision or forced landing."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-394-thrust-reverser-control-system-wiring","history":"/api/acts/ad-b747-394-thrust-reverser-control-system-wiring/history","analysis":"/api/acts/ad-b747-394-thrust-reverser-control-system-wiring/analysis","conflicts":"/api/acts/ad-b747-394-thrust-reverser-control-system-wiring/conflicts","importantCases":"/api/acts/ad-b747-394-thrust-reverser-control-system-wiring/important-cases","documents":"/api/acts/ad-b747-394-thrust-reverser-control-system-wiring/documents"}}