{"id":"F2006B03146","name":"AD/B747/249 - Engine Thrust Control Cables","slug":"ad-b747-249-engine-thrust-control-cables","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42518,"registerId":"commonwealth-F2006B03146-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/249 - Engine Thrust Control Cables","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)\n\nBoeing 747 Series Aeroplanes\n\nAD/B747/249 Engine Thrust Control Cables 7/2001\n\nApplicability: Boeing Model 747-100, -200B, -200C, -200F and -300 series aeroplanes equipped with Pratt and Whitney Model JT9D-3 or –7 series engines, General Electric Model CF6-45 or –50 series engines, or Rolls-Royce Model RB 211-524 B, C or D series engines; delivered in or modified into stretched upper deck (SUD) configuration and having angle assemblies with Boeing part numbers 015U0454-63 and 015U0454-64 installed at body station 970.\n\nRequirement: 1. Perform a detailed visual inspection and measure the clearance between the engine thrust control cables and the cable penetration holes in accordance with the Cable Chafing Inspection of the Accomplishment Instructions of Boeing Service Bulletin (SB) 747-53-2327, Revision 2. If the clearance is within the limits specified by the SB, no further action is required by this AD.\n\n    2. If, during compliance with Requirement 1, insufficient clearance as specified in SB 747-53-2327 Revision 2 exists, accomplish:\n\n    (a) Modify the cable penetration holes or replace the plate, as applicable, in accordance with Figure 7 of the SB, and\n\n    (b) Perform a detailed visual inspection of the engine thrust control cables in the area of the plate to detect wear and broken wires in accordance with Appendix A of this AD. If any wear outside the criteria contained in Appendix A of this AD is found, replace the cable with a new cable, in accordance with procedures described in the Boeing 747 Maintenance Manual. If wear is within the criteria contained in Appendix A of this AD, no further action is required by this paragraph.\n\nNote: FAA AD 2000-12-15 Amendment 39-11962 refers\n\nCompliance: 1. Unless already accomplished, within 12 months from the effective date of this Directive.\n\n2. Unless already accomplished, prior to further flight if insufficient clearance exists as specified in the SB 747-53-2327 Revision 2, after the inspection as per Requirement 1.\n\nBoeing 747 Series Aeroplanes\n\nAD/B747/249 (Continued)\n\nThis Airworthiness Directive becomes effective on 12 July 2001.\n\nBackground: This Directive is issued to prevent chafing and failure of engine thrust control cables, which could result in severe asymmetric thrust conditions during landing, and consequent reduced controllability of the airplane.\n\n![Signature of Eugene Paul Holzapfel, Delegate of the Civil Aviation Safety Authority.](image.002.png)  \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 1 June 2001\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 13 June 2001.\n\nBoeing 747 Series Aeroplanes\n\nAD/B747/249\n\nAppendix A\n\n  \nEngine Thrust Control Cables 7/2001\n\nINSPECTION PROCEDURE\n\n    Detailed Visual Inspection to Detect Wear\n\n    (a) Perform a detailed visual inspection of the engine thrust control cables in the area of the plate to detect wear.\n\n    (b) Replace the cable assembly if any of the following criteria are met:\n\n    (i) One cable strand had worn wires where one wire cross section is decreased by more than 40 percent (see Figure 1)\n\n    (ii) A kink is found\n\n    (iii) Corrosion is found.\n\n    2. Inspection to Detect Broken Wires\n\n    (a) To check for broken wires, rub a cloth along the length of the cable. The cloth catches on broken wires.\n\n    (b) Replace the cable assembly if any of the following criteria are met.\n\n    (i) Replace the 7x7 cable assembly if there are two or more broken wires anywhere in the total cable assembly.\n\n    (ii) Replace the 7x19 cable assembly if there are four or more broken wires in 12 continuous inches of cable or there are six or more broken wires anywhere in the total cable assembly.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nBoeing 747 Series Aeroplanes\n\nAD/B747/249 Appendix A (Continued)\n\n![Boeing 747 Series Aeroplanes - Engine Thrust Control Cables.](image.003.png)  \n\nFigure 1","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The directive is consistent with its stated purpose in the Background: to prevent chafing and failure of engine thrust control cables that could cause asymmetric thrust. It prescribes inspection, measurement and corrective actions rather than expanding obligations beyond that safety objective."},"complexity_factors":["Narrow technical applicability: specific 747 models, SUD configuration, particular engines and Boeing angle assembly part numbers (Applicability).","Dependency on external manufacturer documents: mandatory compliance with Boeing Service Bulletin 747‑53‑2327 Revision 2 and Boeing 747 Maintenance Manual for procedures (Requirement 1, Requirement 2(b)).","Conditional workflow: initial measurement followed by different corrective actions (modify holes or replace plate) and separate cable inspection/replacement criteria (Requirement 1–2 and Appendix A).","Safety‑critical inspection judgments: detailed visual inspection and wear criteria (e.g. >40% strand cross‑section loss, kink, corrosion) require trained maintenance personnel (Appendix A).","Quantitative failure thresholds for broken wires differ by cable construction (7x7 vs 7x19) and length, introducing measurement/counting complexity (Appendix A, Inspection to Detect Broken Wires).","Dual compliance timing: routine deadline (12 months) versus immediate action prior to further flight if insufficient clearance is found (Compliance).","Potential logistics: parts replacement, access to the penetration area, maintenance downtime and recordkeeping burdens for operators (Requirement and Compliance).","Regulatory authority and enforceability: issued under subregulation 39.1(1) of CAR 1998 by CASA delegate, creating binding legal obligations (preamble)."],"plain_english_summary":"This Airworthiness Directive requires operators of certain Boeing 747‑100/200/300 aeroplanes with a stretched upper deck and specific engine/angle‑assembly combinations to inspect and measure the clearance where engine thrust‑control cables pass through a plate. If clearance or cable wear fails the specified criteria, operators must modify the penetration holes or replace the plate and inspect or replace cables. Compliance is mandated within 12 months or before further flight where insufficient clearance exists. The measure aims to prevent cable chafing and failure that could cause asymmetric thrust."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a standard single-issue airworthiness directive focused on a specific safety defect. The scope remains tightly constrained to the identified chafing issue with engine thrust control cables on the specified aircraft configuration."},"complexity_factors":["Multiple applicability conditions combined with 'and' logic (aircraft model AND engine type AND SUD configuration AND specific part numbers)","Two-stage compliance structure (general deadline vs immediate action if defect found)","Technical reference to external Boeing Service Bulletin (SB 747-53-2327 Revision 2) without reproducing full details","Appendix A contains specific quantitative wear criteria (40% cross-section reduction, specific broken wire counts for different cable types 7x7 vs 7x19)","Cross-reference to FAA AD 2000-12-15 for additional context"],"plain_english_summary":"This airworthiness directive orders operators of certain Boeing 747-100/200/300 series with stretched upper decks and specific engines/parts to inspect engine thrust-control cables where they pass through body-station holes. It addresses chafing that can sever cables and cause loss of thrust control on landing. Operators must measure gaps, repair or modify plates, and replace damaged cables; inspections are due within 12 months of 12 July 2001 and repairs must be completed before flight."},"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-b747-249-engine-thrust-control-cables","history":"/api/acts/ad-b747-249-engine-thrust-control-cables/history","analysis":"/api/acts/ad-b747-249-engine-thrust-control-cables/analysis","conflicts":"/api/acts/ad-b747-249-engine-thrust-control-cables/conflicts","importantCases":"/api/acts/ad-b747-249-engine-thrust-control-cables/important-cases","documents":"/api/acts/ad-b747-249-engine-thrust-control-cables/documents"}}