{"id":"F2006B03534","name":"AD/BAe 146/87 - Pitot Static System","slug":"ad-bae-146-87-pitot-static-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43101,"registerId":"commonwealth-F2006B03534-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.002.png)\n\n![](image.002.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.","sortOrder":0},{"sectionNumber":"AD/BAe 146/87 Pitot Static System 5/2001","sectionType":"part","heading":"AD/BAe 146/87 Pitot Static System 5/2001","content":"# AD/BAe 146/87 Pitot Static System 5/2001\n\nApplicability: All Avro 146-RJ70, RJ85 and RJ100 series aeroplanes with modification HCM01080W embodied.\n\nRequirement: 1. Operators who have not inspected their aircraft as a result of BAe Systems All Operator Message (AOM) 00/029V – Action in accordance with BAe Systems Inspection Service Bulletin ISB.34-338 dated 14 February 2001.\n\n    2. Operators who have inspected their aircraft as a result of AOM 00/029V and can confirm that chafing was not present but cannot demonstrate full compliance with of ISB.34-338 – Complete the outstanding ISB.34-338 actions in accordance with the ISB.\n\n    3. Operators who have inspected their aircraft as a result of AOM 00/029V and can demonstrate full compliance with the contents of ISB.34-338 – No further action is necessary.\n\nNote: These actions have been classified as Mandatory by the CAA(UK).\n\nCompliance: For Requirement 1 – Within three months after the effective date of this Directive.\n\nFor Requirement 2 – Within two years after the effective date of this Directive. This Airworthiness Directive becomes effective on 17 May 2001.\n\nBackground: Operators have reported chafing of the S4 and S5 static pipes against the avionics rack frame 18 starboard outboard pipe clamp position. Loss of integrity of both the S4 and S5 static pipes could result in loss of maximum differential pressure protection for the aircraft.","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD stays within the original safety-focused purpose: to eliminate a specific unsafe condition (chafing of S4 and S5 static pipes) on a narrowly defined set of aircraft. It does not broaden the fleet affected beyond the stated modification code, does not add unrelated requirements, and simply makes compliance with an existing BAe inspection service mandatory within set timeframes. Therefore the scope has not been significantly changed beyond its original intent (Applicability; Requirement; Background)."},"complexity_factors":["Short document (single-page AD)","Narrow applicability: only Avro 146-RJ70/RJ85/RJ100 with mod HCM01080W","Three discrete compliance outcomes (Requirement 1–3)","Two compliance timeframes (3 months and 2 years)","Relies on external manufacturer documents: BAe AOM 00/029V and ISB.34-338 (cross-reference increases practical complexity)","No definitions or multi-layered exceptions in the AD itself","Note referencing CAA(UK) mandatory classification (external regulatory cross-reference)","No nested conditional logic or multiple parts — straightforward yes/no/complete categories"],"plain_english_summary":"**What this directive does (mechanics first)**\n\n- This Airworthiness Directive (AD) requires operators of certain BAe/Avro 146 regional jets to inspect and, if necessary, repair parts of the pitot-static system (the static pipes S4 and S5) where they may be chafing against an avionics rack clamp. The specific required work is the inspection and corrective actions set out in BAe Systems Inspection Service Bulletin ISB.34-338 and the related All Operator Message (AOM 00/029V).\n\n- Which aircraft are covered: **all Avro 146-RJ70, RJ85 and RJ100 series aeroplanes that have modification HCM01080W embodied** (Applicability).\n\n- What operators must do (Requirement):\n  - If an operator has not yet inspected the aircraft under BAe AOM 00/029V: perform the inspection and any corrective actions in ISB.34-338 (Requirement 1).\n  - If an operator inspected the aircraft under that AOM and found no chafing but cannot show they completed every action in ISB.34-338: finish the remaining ISB actions (Requirement 2).\n  - If an operator inspected and can demonstrate full compliance with ISB.34-338: no further action is needed (Requirement 3).\n\n- When it must be done (Compliance):\n  - For operators who have not inspected: within 3 months of the AD’s effective date.\n  - For operators who inspected but have incomplete ISB compliance: within 2 years of the AD’s effective date.\n  - The AD’s effective date given in the document is 17 May 2001.\n\n**Why the AD exists (stated safety reason)**\n\n- The Background explains that operators reported chafing of the S4 and S5 static pipes against the avionics rack frame at a specific clamp position. If both S4 and S5 lose integrity, the aircraft could lose maximum differential pressure protection. The AD directs operators to the manufacturer’s inspection and corrective procedures to eliminate that unsafe condition (Background; Requirement).\n\n**Who pays and who decides**\n\n- Aircraft operators (airlines or operators of the affected aircraft) bear the cost of inspections, any corrective work, parts, labour and associated aircraft downtime required by the ISB (Requirement; Compliance).\n\n- The directive is issued by the CASA delegate under the relevant civil aviation regulation authority (stated at top of the AD). The AD requires compliance “in accordance with” BAe Systems ISB.34-338 and AOM 00/029V (Applicability; Requirement).\n\n**Practical effects on operator behaviour and business choices**\n\n- Operators must schedule inspections and, where necessary, carry out repairs or modifications in line with the manufacturer’s service bulletin. This imposes direct maintenance costs and aircraft downtime.\n\n- Operators who have already inspected must retain documentary evidence of full ISB compliance to avoid repeating the work (Requirement 3). That creates an administrative recordkeeping requirement.\n\n- Independent maintenance organisations can perform the work if they follow the ISB instructions, subject to regulatory approvals and the operator’s contracting choices. The AD does not prescribe a single provider; it prescribes a technical standard (ISB.34-338) to meet.\n\n**Costs, trade-offs and implementation risks**\n\n- Costs: inspection labour, possible replacement parts or rerouting/bracing of static pipes, and lost revenue from aircraft out of service. The AD does not supply funding or exemptions.\n\n- Trade-offs: prompt inspection reduces the aviation safety risk identified but may require airlines to accelerate maintenance schedules or incur additional maintenance hours.\n\n- Implementation risk: the AD depends on the instructions in an external manufacturer document (ISB.34-338 and AOM 00/029V). If operators, maintainers or regulators interpret the ISB differently, disputes about what constitutes “full compliance” could arise.\n\n- Compliance enforcement: the AD classifies the ISB actions as mandatory (the AD notes CAA(UK) classified the actions as mandatory), so regulators may inspect records and enforce non-compliance penalties under aviation safety rules (Note; Requirement).\n\n**Concrete incentives and effects on markets**\n\n- Airlines operating the specified airframes must allocate maintenance budget and hangar time; this imposes short-run costs and may shift maintenance demand to providers able to perform the ISB work promptly.\n\n- There is no direct effect on competition, ownership or pricing beyond routine maintenance-market demand changes: the AD prescribes a technical standard to be met, not a procurement method or exclusive supplier arrangement (Requirement; Compliance).\n\n**What to watch for in practice**\n\n- Operators should ensure documentary proof of ISB compliance is retained and accessible to the regulator.\n\n- Where inspections reveal chafing, operators should follow the ISB’s corrective steps exactly to satisfy the AD’s compliance requirement and to avoid repeated or prolonged grounding.\n\n(References: Applicability; Requirement 1–3; Compliance; Background.)"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope — addressing a specific unsafe condition (chafing of S4/S5 static pipes) on specific aircraft models. The three-tiered requirement structure simply accommodates operators at different stages of compliance with the manufacturer's original safety bulletin, without expanding beyond the original safety purpose."},"complexity_factors":["Short, single-purpose directive with only 3 conditional requirements based on prior operator actions","No defined terms section — relies on external technical references (AOM 00/029V, ISB.34-338, modification HCM01080W)","Simple conditional logic: three mutually exclusive pathways based on compliance status","Single cross-reference to UK CAA classification and manufacturer service bulletins","Clear compliance deadlines with straightforward effective date"],"plain_english_summary":"This safety order requires operators in Australia of BAe 146/Avro RJ70, RJ85 and RJ100 aircraft with modification HCM01080W to inspect and repair pitot‑static S4/S5 pipes that are chafing against a frame, following BAe ISB.34‑338. If not yet inspected, complete actions within 3 months; if inspection begun but incomplete, finish within 2 years; already compliant operators need do nothing further.\n\nThe measure prevents simultaneous failure of both pipes, which could remove key cabin pressure protection and endanger passengers and crew."},"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-bae-146-87-pitot-static-system","history":"/api/acts/ad-bae-146-87-pitot-static-system/history","analysis":"/api/acts/ad-bae-146-87-pitot-static-system/analysis","conflicts":"/api/acts/ad-bae-146-87-pitot-static-system/conflicts","importantCases":"/api/acts/ad-bae-146-87-pitot-static-system/important-cases","documents":"/api/acts/ad-bae-146-87-pitot-static-system/documents"}}