{"id":"F2006B09251","name":"AD/DHC-8/91 - Emergency Exit Door Valve - Replacement","slug":"ad-dhc-8-91-emergency-exit-door-valve-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53191,"registerId":"commonwealth-F2006B09251-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\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 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\nBombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/DHC-8/91 Emergency Exit Door Valve - ","sectionType":"part","heading":"AD/DHC-8/91 Emergency Exit Door Valve - Replacement 5/2003","content":"# AD/DHC-8/91 Emergency Exit Door Valve \\- Replacement 5/2003\n\nApplicability: Bombardier DHC-8 aeroplane models 301, 311, 314 and 315, serial numbers 100\n\nthrough 593.\n\nRequirement: Replace the existing pressure control valve part number (P/N) 75290151-001 with P/N 505702 valve per the requirements of Transport Canada AD CF-2003-04.\n\nCompliance: Within 30 months after the effective date of this directive.\n\nThis Airworthiness Directive becomes effective on 15 May 2003.\n\nBackground: Freezing of the control valve, which could prevent opening of the emergency exit door is replaced by this directive.\n\n![](image.002.png)  \n\nJames Coyne\n\nDelegate of the Civil Aviation Safety Authority 4 April 2003\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 23 April 2003.","sortOrder":1}],"analysis":{"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 mechanical defect in a specific aircraft type with a specific remedy. There is no evidence of scope creep; the directive does exactly what its title suggests—mandates replacement of a single faulty valve on specific DHC-8 aircraft."},"complexity_factors":["Very short document (under 300 words)","Only 4 defined elements: specific aircraft models, serial number range, old part number, new part number","Single, unambiguous action required (replacement of one component)","Clear compliance deadline (30 months from effective date)","No nested conditions or exceptions","Cross-reference to only one external document (Canadian AD CF-2003-04) for technical instructions","No interpretation section or defined terms clause"],"plain_english_summary":"This safety order requires replacement of a faulty emergency-exit pressure control valve on Bombardier DHC-8 (Dash 8) aircraft (models 301/311/314/315, S/Ns 100–593) because the old valve can freeze and trap passengers during an emergency.  \n\nAircraft owners, operators and maintenance crews must install the specified replacement valve per the referenced Canadian directive within the stated compliance deadline to eliminate the life‑safety hazard."},"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 does not change scope from its stated purpose: it mandates a specific valve replacement for defined DHC-8 models/serials to prevent valve freezing. It mirrors Transport Canada AD CF-2003-04 and confines action to the listed parts, aircraft, and timetable. No broader applicability, operational restrictions, exemptions, or alternative compliance measures are introduced in the text."},"complexity_factors":["Single, prescriptive technical action (valve replacement) — Requirement section","Narrow applicability to particular models and serial numbers (models 301, 311, 314, 315; s/n 100–593) — Applicability section","Fixed compliance window (within 30 months of the effective date) — Compliance section","Cross-reference to Transport Canada AD CF-2003-04 creates dependency on external service instructions — Requirement/Background","Regulatory basis set out under CASR subregulation 39.1(1) (delegate-issued AD) limits procedural complexity but centralises enforcement — prefatory text","Operational/logistical burdens borne by operators (part procurement, maintenance scheduling, downtime) implied by Requirement and Compliance","No alternative methods of compliance or exemption procedures specified in the text, increasing rigidity — Requirement/Compliance","Effective date and Gazette notification establish a fixed enforcement timeline (effective 15 May 2003; Gazette notice 23 April 2003) — Background"],"plain_english_summary":"This directive requires operators of Bombardier DHC‑8 aeroplanes (models 301, 311, 314, 315; serial numbers 100–593) to replace the emergency-exit pressure control valve P/N 75290151‑001 with P/N 505702, following Transport Canada AD CF‑2003‑04, within 30 months (effective 15 May 2003). It was issued by the Civil Aviation Safety Authority under subregulation 39.1(1) to address valve freezing that could prevent opening an emergency exit. Operators must procure and fit the part and schedule the work; CASA enforces compliance."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-91-emergency-exit-door-valve-replacement","history":"/api/acts/ad-dhc-8-91-emergency-exit-door-valve-replacement/history","analysis":"/api/acts/ad-dhc-8-91-emergency-exit-door-valve-replacement/analysis","conflicts":"/api/acts/ad-dhc-8-91-emergency-exit-door-valve-replacement/conflicts","importantCases":"/api/acts/ad-dhc-8-91-emergency-exit-door-valve-replacement/important-cases","documents":"/api/acts/ad-dhc-8-91-emergency-exit-door-valve-replacement/documents"}}