{"id":"F2006B03659","name":"AD/BEECH 1900/40 - Fuselage Rivets","slug":"ad-beech-1900-40-fuselage-rivets","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43249,"registerId":"commonwealth-F2006B03659-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \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\nBeechcraft 400 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/BEECH 400/20 Bleed Air Supply Tube As","sectionType":"part","heading":"AD/BEECH 400/20 Bleed Air Supply Tube Assembly 9/2001","content":"# AD/BEECH 400/20 Bleed Air Supply Tube Assembly 9/2001\n\nApplicability: Model 400A aeroplanes.\n\nRequirement: Visually inspect the bleed air supply tube assemblies for broken wire braiding on the bellows assemblies or for ruptured or leaking bellows assemblies. The bleed air supply tubes are located within the aft fuselage and connect with mating ducting in the pylon area on the right and left side of the aircraft.\n\nIf any braiding wires are broken or if any bellows assembly is found to be leaking replace the defective duct with a serviceable duct before further flight.\n\nNote 1: FAA AD 2001-03-06 refers.\n\nNote 2: Compliance with the relevant procedures specified in Chapter 4, “Airworthiness Limitations” in the Raytheon Beechjet 400/400A Maintenance Manual, Revision B26, satisfies the intent of this Directive.\n\nCompliance: Unless previously accomplished, within 200 flight hours from the effective date of this Airworthiness Directive and thereafter at intervals not to exceed 400 flight hours.\n\nThis Airworthiness Directive becomes effective on 6 September 2001.\n\nBackground: This Directive is prompted by advice that failure of the engine bleed air supply tube can occur resulting in high temperature bleed air impinging on surrounding structure, wiring and components.\n\n![](image.002.png)  \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 27 July 2001\n\n![](image.001.png)","sortOrder":1}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"N/A - This is a discrete, single-issue safety directive addressing a specific mechanical failure mode in a specific aircraft type. No scope creep evident."},"complexity_factors":["Single aircraft model applicability (Model 400A only)","One primary requirement with straightforward conditional logic (inspect → replace if defective)","Simple compliance timeline (200 hours initial, 400 hours recurring)","Only 2 cross-references (FAA AD and maintenance manual)","No defined terms section or interpretation provisions","Single unsafe condition addressed with direct remedy"],"plain_english_summary":"This CASA Airworthiness Directive requires owners, operators and maintenance engineers of Beechcraft 400A (Beechjet) aircraft to inspect flexible bleed-air supply tubes in the aft fuselage and engine pylons for broken wire braiding or leaking bellows, and to replace any defective ducts before further flight.  \n\nThe rule prevents hot bleed air from damaging structure, wiring or systems and creating a fire risk; compliance via the manufacturer’s maintenance procedure satisfies the requirement."},"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":"This AD is narrowly focused on correcting an identified unsafe condition for the bleed air supply tube assembly on Beechcraft 400A aeroplanes. It does not expand beyond that technical fix: the applicability, required action (inspect and replace), and compliance intervals are all aligned with the stated safety purpose in the Background. There is no substantive extension of scope beyond addressing the bleed air duct failure risk described in the Directive."},"complexity_factors":["Short document with a single clear technical requirement (visual inspection and replace if defective).","One aircraft type in Applicability (Model 400A) — narrow scope.","Cross-references limited to two external documents: FAA AD 2001-03-06 (Note 1) and the Raytheon Beechjet 400/400A Maintenance Manual Revision B26 (Note 2).","Simple compliance timetable with two numeric thresholds (initial within 200 flight hours; recurring not to exceed 400 flight hours).","No nested exceptions or multiple conditional branches; action is binary (inspect; if defective then replace).","No extensive defined-terms section or multiple Parts/Divisions to cross-reference."],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- It is an Airworthiness Directive (AD) that applies to Beechcraft Model 400A aeroplanes. (Applicability)\n- It requires operators to visually inspect the engine bleed air supply tube assemblies (located in the aft fuselage and connecting to pylon ducting) for broken wire braiding on the bellows or for ruptured/leaking bellows. (Requirement)\n- If any broken braiding wires or leaking/ruptured bellows are found, the defective duct must be replaced with a serviceable part before the aircraft can fly again. (Requirement)\n- The inspections must be done within 200 flight hours from the AD’s effective date and then repeated at intervals not exceeding 400 flight hours. (Compliance)\n- Compliance with the specified procedures in Chapter 4, “Airworthiness Limitations”, of the Raytheon Beechjet 400/400A Maintenance Manual (Revision B26) meets the AD’s intent. (Note 2)\n\n**Who is affected**\n\n- Owners and operators of Beechcraft 400A aeroplanes are the parties responsible for carrying out the inspections and any required replacements. (Applicability, Requirement, Compliance)\n- Maintenance organisations and certified mechanics who perform scheduled maintenance on these aeroplanes are affected because they must carry out the inspections and any repairs/replacements according to the AD and the referenced maintenance manual. (Requirement, Note 2)\n\n**Why it matters (official rationale and practical implications)**\n\n- The stated safety concern is that a failed bleed air supply tube can allow high-temperature bleed air to impinge on nearby structure, wiring or components, creating an unsafe condition. (Background)\n- Mechanically, the AD forces more frequent inspection and replacement of a specific duct assembly to reduce the risk that a leak or rupture will cause heat damage. (Requirement, Compliance)\n\n**Costs, incentives and trade-offs**\n\n- Direct costs: operators pay for the inspections, any spare parts, and labour for replacements where defects are found. (Requirement, Compliance)\n- Scheduling burden: required inspections on a flight-hour schedule (first within 200 hours, then every 400 hours) may require earlier out-of-service time or integration into existing maintenance checks. (Compliance)\n- Parts availability risk: if replacement ducts are in limited supply, operators could face delays or higher parts costs; that may push work to authorised dealers or large maintenance providers. (Requirement)\n- Opportunity cost: time spent on these inspections and replacements displaces other maintenance activities or revenue-generating flight hours. (Compliance)\n- Incentives: the AD creates an incentive for operators to track these ducts closely and to prioritise replacement where deterioration is seen, which may increase demand for authorised repair/parts services. (Requirement)\n\n**Implementation, discretion and compliance mechanisms**\n\n- The AD is a prescriptive safety measure imposed by the regulator (the CASA delegate issued it under the relevant aviation regulation). It sets a mandatory inspection timetable and a mandatory fix (replace before further flight if defective). (Introductory paragraph, Requirement, Compliance)\n- The AD references the aircraft manufacturer’s maintenance manual procedures as satisfying its intent; that channels maintenance work toward established procedures and recorded maintenance practices. (Note 2)\n- Enforcement is by civil aviation regulatory mechanisms (failure to comply would leave an aircraft non-compliant with its continuing airworthiness obligations). (General operation of ADs)\n\n**Effects on market participants and competition**\n\n- Small operators bear the same per-aircraft costs as large operators, so costs are proportionately larger for operators with fewer aircraft.\n- Maintenance shops and parts suppliers that stock the specific ducts or have the capability to replace them stand to receive the work; independent repair stations that are approved to work on these aircraft can compete for that work provided they comply with the maintenance manual and regulatory requirements. (Requirement, Note 2)\n\n**Summary statement**\n\nThis AD requires periodic visual inspection of the bleed air supply tube assemblies on Beechcraft 400A aeroplanes and replacement of any defective duct before further flight, with specific inspection intervals. The explicit safety objective is to prevent hot bleed air from damaging surrounding structure or systems. Operators and maintenance providers carry the direct costs and scheduling burden; the AD relies on existing maintenance manual procedures to define acceptable ways to comply. (Requirement, Compliance, Note 2, Background)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-1900-40-fuselage-rivets","history":"/api/acts/ad-beech-1900-40-fuselage-rivets/history","analysis":"/api/acts/ad-beech-1900-40-fuselage-rivets/analysis","conflicts":"/api/acts/ad-beech-1900-40-fuselage-rivets/conflicts","importantCases":"/api/acts/ad-beech-1900-40-fuselage-rivets/important-cases","documents":"/api/acts/ad-beech-1900-40-fuselage-rivets/documents"}}