{"id":"F2006B03147","name":"AD/B747/249 Appendix A - Engine Thrust Control Cables","slug":"ad-b747-249-appendix-a-engine-thrust-control-cables","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42519,"registerId":"commonwealth-F2006B03147-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"INSPECTION PROCEDURE","sectionType":"part","heading":"INSPECTION PROCEDURE","content":"# INSPECTION 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.","sortOrder":0},{"sectionNumber":"2. Inspection to Detect Broken Wires","sectionType":"part","heading":"2. Inspection to Detect Broken Wires","content":"# 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.","sortOrder":1}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This appears to be a complete, standalone airworthiness directive focused specifically on Boeing 747 engine thrust control cable inspections. The scope is narrow and technical, limited to maintenance procedures for a specific aircraft component, which aligns with the typical purpose of an AD. There is no evidence of scope creep or expansion beyond original safety intent."},"complexity_factors":["Very short document (approximately 200 words)","Only 2 defined technical terms (7x7 and 7x19 cable types, which refer to strand construction)","No cross-references to other legislation or regulations","Simple conditional logic with clear numerical thresholds (40% wear, 2/4/6 broken wire counts)","Straightforward procedural structure (inspect → if found → replace)","No exceptions, exemptions, or nested conditions"],"plain_english_summary":"This document sets out safety inspection rules for Boeing 747 aircraft engine thrust control cables. These cables connect the pilot's throttle controls to the engines, so if they fail, the pilot can't control engine power.\n\n**What it requires:**\n- **Two types of inspections** must be carried out on these cables:\n  1. **Visual inspection for wear** — looking for worn wires, kinks, or corrosion where the cable passes through a plate\n  2. **Physical check for broken wires** — running a cloth along the cable to catch on any broken strands\n\n**When cables must be replaced:**\n- If any single wire has lost more than 40% of its cross-section (thickness) due to wear\n- If there's a kink (a sharp bend that damages the cable)\n- If there's corrosion (rust or deterioration)\n- If too many wires are broken:\n  - For 7×7 cables (7 strands of 7 wires each): 2+ broken wires anywhere\n  - For 7×19 cables (7 strands of 19 wires each): 4+ broken wires in any 12-inch section, or 6+ broken wires total\n\n**Who it affects:**\nAircraft maintenance engineers and airlines operating Boeing 747s. This appears to be an Airworthiness Directive (AD) — a mandatory safety order issued by aviation regulators.\n\n**Why it matters:**\nEngine thrust control cables are critical safety components. If they break or fail, pilots could lose control of engine power during flight, potentially leading to catastrophic accidents. These rules prevent that by mandating specific inspection methods and clear replacement thresholds."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The provided text sets out inspection procedures and replacement thresholds for engine thrust control cables only. It does not indicate any amendment, extension, or narrowing of scope beyond those procedures. There is no language in the excerpt suggesting a change from a prior scope or intent; the document simply prescribes how to inspect and when to replace specific cable assemblies (Inspection Procedure (a)–(b); Section 2(a)–(b))."},"complexity_factors":["Short, focused text with a single technical objective (inspection and replacement criteria).","Clear, numeric thresholds (e.g. >40% wire cross‑section loss; 2 broken wires for 7x7; 4 broken within 12 inches or 6 overall for 7x19).","Simple, low‑ambiguity inspection methods (visual inspection; cloth rub) but reliant on human technique.","Limited branching: separate, explicit rules for wear, kinks, corrosion, and broken‑wire counts.","Some technical terms (7x7 vs 7x19 cable constructions; '% cross‑section') that require basic familiarity with cable types/measuring wire loss."],"plain_english_summary":"This Appendix prescribes step‑by‑step visual and cloth‑rub inspections and objective replacement thresholds for engine thrust‑control cable assemblies. It requires replacement if a single wire’s cross‑section is reduced >40%, or if a kink or corrosion is found; broken‑wire triggers are: 7x7 — ≥2 broken anywhere; 7x19 — ≥4 within 12 inches or ≥6 anywhere.\n\nThe rules bind aircraft operators and maintenance organisations to perform these manual checks, imposing labour, downtime and replacement costs while removing ambiguity about when a cable assembly must be replaced."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-249-appendix-a-engine-thrust-control-cables","history":"/api/acts/ad-b747-249-appendix-a-engine-thrust-control-cables/history","analysis":"/api/acts/ad-b747-249-appendix-a-engine-thrust-control-cables/analysis","conflicts":"/api/acts/ad-b747-249-appendix-a-engine-thrust-control-cables/conflicts","importantCases":"/api/acts/ad-b747-249-appendix-a-engine-thrust-control-cables/important-cases","documents":"/api/acts/ad-b747-249-appendix-a-engine-thrust-control-cables/documents"}}