{"id":"F2006B03619","name":"AD/BEECH 18/20 - Lower Rudder Torque Tube - Inspection","slug":"ad-beech-18-20-lower-rudder-torque-tube-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43210,"registerId":"commonwealth-F2006B03619-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEECH 18/20 - Lower Rudder Torque Tube - Inspection","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)  \nBeechcraft 18 Series Aeroplanes\n\nAD/BEECH 18/20 Lower Rudder Torque Tube \\- Inspection 6/78\n\nApplicability: All models D18C, D18S, E18S, E18S-9700, G18S, H-18, C-45G TC-45G, C-45H,\n\nTC-45J (SNB-5), JRB-6, 3N, 3M and 3NM modified in accordance with STC SA 1243WE, S1016WE or SA360WE.\n\nRequirement: Visually inspect the lower rudder torque tube P/N 452606-7 for cracks in the area of the access hole.\n\nNote 1: Cracked tubes in which the length of cracks does not exceed 0.50 inch (12.5 mm) may be repaired to a scheme approved by the Secretary. If cracks exceed 0.50 inch the tube shall be replaced before further flight.\n\nNote 2: FAA AD 78-10-1 AMDT. 39-3210 refers.\n\nCompliance: Within 100 hours time in service after 30 June 1978 and thereafter at intervals not exceeding 100 hours time in service.\n\nFederal Register of Legislative Instruments F2006B03619","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive focused on a specific mechanical defect in specific aircraft models. It has not expanded beyond its original purpose of ensuring rudder torque tube integrity."},"complexity_factors":["Single, specific mechanical component targeted (lower rudder torque tube P/N 452606-7)","Straightforward binary compliance: inspect, then repair or replace based on crack length","Simple recurring interval: every 100 hours time in service","Limited applicability: specific aircraft models with specific modifications (STC SA 1243WE, S1016WE or SA360WE)","No nested exceptions or conditional logic — just one measurement threshold (0.50 inch/12.5mm)","Short document (approximately 200 words)","Only 2 notes providing guidance, no extensive cross-referencing within the instrument itself"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order for aircraft owners and operators. It applies to specific models of **Beechcraft 18 series aeroplanes** (including military variants like the C-45 and SNB-5) that have been modified in certain ways.\n\n**What it requires:**\n- **Visual inspection** of a specific part called the \"lower rudder torque tube\" (part number 452606-7) — this is a component that helps control the rudder, which steers the aircraft left and right.\n- The inspection must look for **cracks around an access hole** in this tube.\n\n**What happens if you find cracks:**\n- **Small cracks** (12.5mm or less): Can be repaired using a scheme approved by the Secretary (the aviation safety regulator).\n- **Larger cracks**: The tube must be **replaced before the aircraft can fly again**.\n\n**When to do it:**\n- First inspection: Within 100 hours of flying time after 30 June 1978.\n- **Repeat every 100 flight hours** thereafter.\n\n**Why it matters:**\nCracks in a rudder control component could lead to loss of directional control of the aircraft — a serious safety risk. This directive ensures potential failures are caught early through regular inspection."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument as presented sets inspection, repair and replacement requirements for a specified part on listed Beechcraft 18-series aircraft and those modified under identified STCs. The text does not indicate any change from an earlier or different scope; it prescribes the same focused inspection obligation, threshold for allowable repair, and replacement requirement for larger cracks, and specifies the inspection interval. (Applicability; Requirement; Note 1; Compliance)"},"complexity_factors":["Narrow technical focus: single part (lower rudder torque tube P/N 452606-7) and specific area to inspect (access hole). (Requirement)","Clear numerical threshold for action (0.50 inch / 12.5 mm) which simplifies decision-making. (Note 1)","Recurring compliance interval specified (every 100 hours time in service) plus an initial deadline, creating an ongoing operational requirement. (Compliance)","Administrative discretion required for approving repair schemes (repair allowed only if approved by the Secretary). (Note 1)","Applicability covers multiple airframe models and certain STC-modified aircraft, requiring operators to check applicability precisely. (Applicability)","Reference to external FAA AD for context (Note 2) introduces cross-jurisdictional linkage that may require consultation of another instrument for full background."],"plain_english_summary":"This AD requires owners/operators of specified Beechcraft 18-series (including aircraft modified under STCs SA1243WE, S1016WE, SA360WE) to visually inspect lower rudder torque tube P/N 452606-7 at the access-hole area within 100 hours TIS after 30 Jun 1978 and every 100 hours thereafter. Cracks >0.50 inch must be replaced before flight; cracks ≤0.50 inch may be repaired only under a repair scheme approved by the Secretary. Operators bear inspection, repair/replacement costs and any approval delay."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-18-20-lower-rudder-torque-tube-inspection","history":"/api/acts/ad-beech-18-20-lower-rudder-torque-tube-inspection/history","analysis":"/api/acts/ad-beech-18-20-lower-rudder-torque-tube-inspection/analysis","conflicts":"/api/acts/ad-beech-18-20-lower-rudder-torque-tube-inspection/conflicts","importantCases":"/api/acts/ad-beech-18-20-lower-rudder-torque-tube-inspection/important-cases","documents":"/api/acts/ad-beech-18-20-lower-rudder-torque-tube-inspection/documents"}}