{"id":"F2006B03927","name":"AD/BEECH 400/24 - Low Pressure Oxygen Tubing","slug":"ad-beech-400-24-low-pressure-oxygen-tubing","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43536,"registerId":"commonwealth-F2006B03927-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\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 CASR 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\nBeechcraft 400 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/BEECH 400/24 Low Pressure Oxygen Tubi","sectionType":"part","heading":"AD/BEECH 400/24 Low Pressure Oxygen Tubing 8/2003","content":"# AD/BEECH 400/24 Low Pressure Oxygen Tubing 8/2003\n\nApplicability: Model Beech 400A series aeroplanes, serial numbers RK-232 through RK-265 inclusive; and Model Beech 400T series aeroplane serial number TX-10.\n\nRequirement: For Model 400A series aeroplanes \\- Replace the low-pressure oxygen tubing located in the forward fuselage (nose avionics bay), lower forward flight deck, and lower forward cabin areas, as applicable, with new low-pressure oxygen tubing, in accordance with Part I of the Accomplishment Instructions specified in Raytheon Service Bulletin SB 35-3406, dated March 2001.\n\nFor Model 400T series aeroplanes \\- Replace the low-pressure oxygen tubing located in the forward fuselage (nose avionics bay), lower forward flight deck, and lower forward cabin areas, as applicable, with new low-pressure oxygen tubing, in accordance with Part II of the Accomplishment Instructions specified in SB 35-3406.\n\nNote: FAA AD 2003-10-13 Amdt 39-13158 refers.\n\nCompliance: Within 200 hours time in service or one year, whichever occurs first, from the effective date of this Directive.\n\nThis Airworthiness Directive becomes effective on 7 August 2003.\n\nBackground: This Directive requires replacement of the low-pressure oxygen tubing located in the forward fuselage (nose avionics bay), lower forward flight deck and lower forward cabin areas, as applicable, with new low-pressure oxygen tubing. This action is necessary to prevent leakage of oxygen from scored low-pressure oxygen tubing, which could result in lack of available oxygen for the flight crew, or possible explosion or fire.\n\n![Signature: Jim Coyne](image.002.png)  \n\nJim Coyne\n\nDelegate of the Civil Aviation Safety Authority 26 June 2003\n\n![](image.001.png)","sortOrder":1}],"analysis":{"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"},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The Directive stays within its original, stated safety purpose: to correct a specific unsafe condition (scored low‑pressure oxygen tubing) by requiring replacement of that tubing. It does not broaden regulatory reach beyond that corrective action — applicability is limited to identified serial numbers, the action is narrowly defined and tied to the manufacturer's service bulletin, and the compliance window is finite. There is no evidence in the text that the Directive expands scope beyond the original safety concern described in the Background section."},"complexity_factors":["Narrow applicability: only specific serial numbers (RK-232 through RK-265; TX-10) — limited population","Single required action (replace specified tubing) with explicit reference to a single manufacturer Service Bulletin (SB 35-3406, Parts I/II)","One compliance condition: deadline expressed as 200 flight hours or one year, whichever comes first","Cross-reference to FAA AD (2003-10-13) but no layered conditional exemptions or multi-step inspections","Short document length and few defined terms or nested exceptions"],"plain_english_summary":"**What this directive does (mechanics)\n\n- Applies to: Beechcraft Model 400A aeroplanes with serial numbers RK-232 through RK-265, and Beechcraft Model 400T serial number TX-10. (See \"Applicability\".)\n\n- Required action: Replace the low‑pressure oxygen tubing located in the forward fuselage (nose avionics bay), lower forward flight deck, and lower forward cabin areas, as applicable. Model 400A aircraft must follow Part I of the Accomplishment Instructions in Raytheon Service Bulletin SB 35-3406 (March 2001). Model 400T aircraft must follow Part II of that Service Bulletin. (See \"Requirement\".)\n\n- Timing: The replacement must be done within 200 hours time in service or within one year from the AD’s effective date, whichever comes first. (See \"Compliance\".)\n\n- Authority: This is an Airworthiness Directive issued by the Civil Aviation Safety Authority (CASA) under the aviation safety regulations. The Delegate signed the Directive and set the effective date. (See header and signature.)\n\n**Why it was issued (stated reason)\n\n- The Directive says the tubing can become scored and leak oxygen. The stated safety risks are that oxygen leakage could lead to a lack of available oxygen for the flight crew and, separately, to possible explosion or fire. The Directive therefore requires replacement of the tubing to correct that unsafe condition. (See \"Background\".)\n\n**Who is affected and who pays\n\n- Directly affected: Owners/operators of the specific Beech 400A and the one identified Beech 400T aircraft listed in the Applicability section.\n- Who pays: The aircraft owner/operator pays for parts, labour and aircraft downtime necessary to perform the replacement in accordance with the service bulletin.\n- Who decides how it is done: The AD mandates compliance with the Raytheon Service Bulletin procedures; maintenance must be carried out in accordance with those instructions unless an alternative is approved by the regulator.\n\n**Practical effects and implementation notes (trade-offs, incentives, risks)\n\n- Compliance burden: The work is a discrete maintenance/repair action defined by the manufacturer’s Service Bulletin. The burden is concentrated on a small, identified group of aircraft. Costs are the parts and labour plus aircraft out‑of‑service time.\n- Timing/trade‑off: The Directive sets a finite compliance window (200 flight hours or 1 year). Operators may need to schedule maintenance sooner than planned, affecting dispatch and revenue for those aircraft.\n- Parts and providers: The AD specifies following the Raytheon Service Bulletin; that channels the required technical steps and likely the parts source. Operators may need to source parts or approved equivalents; alternatives require regulator approval.\n- Safety benefit vs cost: The Directive’s stated benefit is preventing oxygen leakage (safety gain). The cost is borne by the listed aircraft owners/operators in the form of maintenance expense and downtime.\n- Enforcement and discretion: The AD is mandatory under CASA authority; the regulator (or its delegate) enforces compliance. There is limited discretion for operators — they must follow the Service Bulletin or obtain an approved deviation.\n- Inter-jurisdictional reference: The AD notes an FAA AD (2003-10-13) as a related reference, indicating harmonisation with the FAA’s corrective action for the same unsafe condition.\n\n**Bottom line (plainly)\n\nThis is a targeted safety order requiring a specific replacement job (low‑pressure oxygen tubing in specified forward areas) on a small set of Beech 400 aircraft within a short, fixed time window. The regulator prescribes following the manufacturer’s Service Bulletin; operators must pay for and schedule the work. The stated aim is to remove a risk of oxygen leakage that could lead to loss of crew oxygen or fire/explosion.\n"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope. It addresses a specific safety defect in specific aircraft models and requires a specific remedial action. There is no evidence of scope creep; the directive does exactly what its title and background suggest—mandates replacement of faulty oxygen tubing in identified aircraft."},"complexity_factors":["Very short document (approximately 300 words)","Only 2 defined applicability groups (Model 400A series with specific serial numbers, and Model 400T series with one serial number)","Single straightforward requirement with two parallel sub-requirements (one per model)","No nested exceptions or conditional logic beyond the model-specific applicability","Simple compliance timeframe (200 hours OR 1 year, whichever first)","Only one external reference (FAA AD 2003-10-13) mentioned in a note, not incorporated by complex cross-reference","Clear, direct language with minimal aviation jargon"],"plain_english_summary":"This is a safety order for specific Beechcraft aeroplanes. It requires owners or operators of certain Beech 400A and 400T model planes to replace old oxygen tubing in the front sections of the aircraft with new tubing. The old tubing can develop scratches (\"scored\" means scratched or grooved) that may cause oxygen to leak out. This is dangerous because it could leave pilots without oxygen at high altitudes, or worse, cause a fire or explosion since oxygen feeds flames. The replacement must be done within 200 flight hours or one year from when the order takes effect (7 August 2003), whichever comes first. The work must follow specific instructions in a manufacturer service bulletin."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-400-24-low-pressure-oxygen-tubing","history":"/api/acts/ad-beech-400-24-low-pressure-oxygen-tubing/history","analysis":"/api/acts/ad-beech-400-24-low-pressure-oxygen-tubing/analysis","conflicts":"/api/acts/ad-beech-400-24-low-pressure-oxygen-tubing/conflicts","importantCases":"/api/acts/ad-beech-400-24-low-pressure-oxygen-tubing/important-cases","documents":"/api/acts/ad-beech-400-24-low-pressure-oxygen-tubing/documents"}}