{"id":"F2006B09255","name":"AD/DHC-8/96 - Brake Hydraulic System","slug":"ad-dhc-8-96-brake-hydraulic-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53206,"registerId":"commonwealth-F2006B09255-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-8/96 Brake Hydraulic System 4/200","sectionType":"part","heading":"AD/DHC-8/96 Brake Hydraulic System 4/2004","content":"# AD/DHC-8/96 Brake Hydraulic System 4/2004\n\nApplicability: Bombardier Inc. DHC-8, Models 102, 103, 106, 201, 202, 301, 311, 314 and 315,\n\nSerial Numbers 003 through 593.\n\nRequirement: 1. Install check valves in the Number 1 and Number 2 hydraulic return systems by incorporating Modsum 8Q101320 in accordance with Bombardier Service Bulletin (SB) 8-29-36, Revision B, dated 6 January 2003.\n\n    2. Modify the brake shuttle valves, P/N 5084-1, to remove filter assemblies by incorporating either Modsum 8Q101316 or 8Q101422 in accordance with Bombardier SB 8-29-37, Revision A, dated 19 September 2003, and SB 8-29-39, Initial Issue, dated 14 July 2003.\n\n    3. Incorporate Modsum 8Q101316 to remove the internal garter spring from the brake shuttle valve in accordance with Bombardier SB 8-29-37, Revision A.\n\nNote 1: Canadian AD CF-2004-02 refers.\n\nNote 2: Modsum 8Q101320 is required as a prerequisite prior to the installation of one or more shuttle valves that has been modified per Modsum 8Q101316. It is permissible to have a mix of shuttle valves that incorporated either Modsum 8Q101316 or 8Q101422.\n\nCompliance: For Requirements 1 and 2. Unless previously accomplished within 12 months after the effective date of this Directive.\n\nFor Requirement 3. Subsequent to the accomplishment of Requirements 1 and 2 of this directive, and prior to installation on an aircraft following overhaul of each brake shuttle valve, P/N 5084-1A, (i.e. brake shuttle valves with filters removed but internal garter spring not removed).\n\nThis Airworthiness Directive becomes effective on 15 April 2004.","sortOrder":1}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The Directive applies to a defined set of aircraft (serials 003–593) and prescribes precise hardware modifications and timing. It does not expand applicability beyond those aircraft or add unspecified new obligations; it instead specifies required actions, prerequisites and timing (Applicability; Requirements 1–3; Note 2; Compliance)."},"complexity_factors":["Applicability limited to particular models and serial numbers (Applicability).","Multiple distinct modification actions required (Requirements 1–3).","Interdependent requirements and a stated prerequisite: Modsum 8Q101320 must be done before installing certain modified shuttle valves (Requirement 1; Note 2).","Different compliance triggers/timings: a 12‑month window for some actions and an overhaul‑related trigger for another (Compliance).","Permitted mixing of shuttle valve modification types creates tracking and configuration management needs (Note 2).","References to specific Bombardier Service Bulletins and Modsum numbers, including different SB revisions, which maintenance organisations must follow exactly (Requirements 1–3).","Cross-reference to a foreign airworthiness directive (Canadian AD) for context (Note 1)."],"plain_english_summary":"This Airworthiness Directive requires specified modifications to the brake hydraulic system on Bombardier DHC-8 aeroplanes (serials 003–593). Mechanically, it mandates installing check valves in the No.1 and No.2 hydraulic return lines and modifying brake shuttle valves to remove filters and, later, an internal garter spring. It affects aircraft operators and maintenance organisations because those parties must carry out the work within the stated compliance periods to address an identified unsafe condition."},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with a focused, single-purpose scope: correcting a specific unsafe condition in the brake hydraulic system of particular DHC-8 aircraft. The document maintains its original regulatory intent without scope creep."},"complexity_factors":["Multiple interdependent requirements with specific sequencing (Requirement 3 cannot be done before Requirements 1 and 2)","Cross-references to external technical documents (three different Bombardier Service Bulletins with specific revision levels and dates)","Conditional compliance timing with two different deadlines depending on which requirement applies","Prerequisite dependency noted in Note 2 (Modsum 8Q101320 must be installed before certain shuttle valve modifications)","Permissible mixing of modified parts creates an exception condition (mix of Modsum 8Q101316 or 8Q101422 allowed)","Specific part numbers (P/N 5084-1 and P/N 5084-1A) with different modification states requiring careful tracking","Reference to Canadian AD CF-2004-02 indicating international regulatory coordination"],"plain_english_summary":"This CASA Airworthiness Directive mandates safety modifications to the brake hydraulic systems of specific Bombardier DHC‑8 (Dash 8) aircraft (S/N 003–593). Operators and maintenance organisations must install check valves, modify brake shuttle valves to remove filters, and later remove internal springs during valve overhaul.\n\nThe install/modify actions were required within 12 months of 15 April 2004; compliance is legally mandatory for continued operation in Australia."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-96-brake-hydraulic-system","history":"/api/acts/ad-dhc-8-96-brake-hydraulic-system/history","analysis":"/api/acts/ad-dhc-8-96-brake-hydraulic-system/analysis","conflicts":"/api/acts/ad-dhc-8-96-brake-hydraulic-system/conflicts","importantCases":"/api/acts/ad-dhc-8-96-brake-hydraulic-system/important-cases","documents":"/api/acts/ad-dhc-8-96-brake-hydraulic-system/documents"}}