{"id":"F2006B09254","name":"AD/DHC-8/94 - Pitot Static System","slug":"ad-dhc-8-94-pitot-static-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53202,"registerId":"commonwealth-F2006B09254-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\nBombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/DHC-8/94 Pitot Static System 13/2003","sectionType":"part","heading":"AD/DHC-8/94 Pitot Static System 13/2003","content":"# AD/DHC-8/94 Pitot Static System 13/2003\n\nApplicability: DHC-8 aeroplanes Models 102, 103, 106, 201, 202, 301, 311, 314 and 315, serial\n\nnumbers (S/N) 003 through 598 inclusive.\n\nRequirement: If not previously accomplished, carry out the following:\n\nFor aeroplanes S/N 003 through 590 inclusive \\- Provide increased independence between the pilot's primary and standby instrument static pressure source by incorporating ModSum 8Q101238 and 8Q101340 in accordance with Part A and Part C of the Accomplishment Instructions of Bombardier Service Bulletin (SB) 8-34-221, dated 27 May 2003.\n\nFor aeroplanes S/N 591 through 598 inclusive \\- Correct the static system hose length by incorporating ModSum 8Q101340 in accordance with Part B and\n\nPart C of the Accomplishment Instructions of SB 8-34-221.\n\nNote: Transport Canada AD CF-2003-25 refers.\n\nCompliance: Within 24 months after the effective date of this directive\n\nThis Airworthiness Directive becomes effective on 25 December 2003.\n\nBackground: Transport Canada has advised that investigation of an incident involving erroneous readings of the pilot’s flight instruments has revealed that a leak in the pilot’s static pressure system, downstream of the alternate selector valve, could result in a loss of both the pilot’s normal and alternate static systems. This condition could result in the display of misleading altitude or airspeed information to the flight crew.\n\n![](image.002.png)  \n\nJim Coyne\n\nDelegate of the Civil Aviation Safety Authority 14 November 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":5,"scope_assessment":{"changed":false,"description":"The directive applies only to the listed DHC‑8 models and serial numbers 003–598 and mandates specified ModSums per the Bombardier SB. It does not expand applicability beyond those aircraft or add other product categories; it changes the aircraft configuration for affected serials but does not alter the stated scope of affected types (Applicability; Requirement)."},"complexity_factors":["Technical aircraft modification to the pitot/static system requiring adherence to Bombardier SB 8-34-221 Parts A/B/C — requires certified maintenance actions (Requirement).","Different required actions by serial-number ranges (S/N 003–590 vs 591–598), adding logistics and parts-identification complexity (Applicability; Requirement).","Dependence on external documents and approvals: Bombardier Service Bulletin and cross-reference to Transport Canada AD CF-2003-25 (Requirement; Note).","Fixed compliance window of 24 months imposes scheduling, parts procurement and possible operational downtime for operators (Compliance).","Regulatory provenance under CASR subregulation 39.1(1) and signed by a CASA delegate creates mandatory force and limited administrative discretion (preamble/signature).","Safety-critical nature increases certification, record-keeping and inspection burdens for maintenance organisations and operators (Background; Requirement)."],"plain_english_summary":"This AD requires installation of ModSum 8Q101238 and/or 8Q101340 per Bombardier Service Bulletin 8-34-221 on DHC‑8 aeroplanes S/N 003–598 to increase independence between the pilot’s primary and standby static pressure sources and, for late serials, correct static hose length. Aircraft owners/operators must carry out the work within 24 months at their own cost; CASA’s delegate issued the directive to address a reported static-system leak that could cause misleading altitude or airspeed readings (Background; Requirement; Compliance)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This airworthiness directive maintains its original narrow scope — addressing a specific unsafe condition in a specific aircraft type's pitot-static system. There is no evidence of scope creep; it is a targeted safety intervention consistent with the standard purpose of airworthiness directives under the Civil Aviation Safety Regulations."},"complexity_factors":["Single, clearly defined applicability (specific aircraft models and serial numbers)","Straightforward two-part requirement based on serial number ranges","No defined terms section or complex interpretation provisions","Single cross-reference to a Canadian airworthiness directive (CF-2003-25) for context only","Clear, fixed compliance deadline (24 months from effective date)","No nested conditions, exceptions, or discretionary powers","Technical content refers to external manufacturer documents (Service Bulletin) rather than legislating technical details within the instrument itself"],"plain_english_summary":"The order requires operators of Bombardier DHC‑8 (Dash 8) twin‑turboprops (models 100/200/300 series, S/N 003–598) to correct a pitot‑static system design flaw that can let a single static leak disable both primary and standby flight instruments. \n\nFixes—installation/modification per Bombardier service instructions—must be completed within 24 months to prevent dangerous false airspeed/altitude indications that can cause catastrophic accidents."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-94-pitot-static-system","history":"/api/acts/ad-dhc-8-94-pitot-static-system/history","analysis":"/api/acts/ad-dhc-8-94-pitot-static-system/analysis","conflicts":"/api/acts/ad-dhc-8-94-pitot-static-system/conflicts","importantCases":"/api/acts/ad-dhc-8-94-pitot-static-system/important-cases","documents":"/api/acts/ad-dhc-8-94-pitot-static-system/documents"}}