{"id":"F2006B09191","name":"AD/DHC-8/35 Amdt 1 - Engine Nacelle","slug":"ad-dhc-8-35-amdt-1-engine-nacelle","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52992,"registerId":"commonwealth-F2006B09191-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-8/35 Amdt 1 - Engine Nacelle","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nBombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes\n\nAD/DHC-8/35\n\nAmdt 1\n\n  \nEngine Nacelle 6/95\n\nApplicability: Model DHC-8 Series 100 and 300 aircraft, with serial numbers as indicated in the Requirement section of this Directive.\n\nRequirement: 1. For aircraft serial numbers 3 through 137, install Modification 8/1126 (Nacelles- Sealing of Lower Cowl Firewall). De Havilland SB 8-54-12 refers.\n\n    2. For aircraft serial numbers 3 through 331, install Modification 8/1885 (Nacelle- Upper Structure Access Panel Sealing). De Havilland SB 8-54-25 refers.\n\n    3. For aircraft serial numbers 3 through 332, install Modification 8/1887 (Nacelles/Pylons \\- Firewall \\- Improvements to Fireproof and Leakproof Integrity). De Havilland SB 8-54-30 Revision B refers.\n\n    4. For aircraft serial numbers 3 through 357, install Modification 8/1966 (Nacelles/Pylons \\- Firewall \\- Addition of Sealant). De Havilland SB 8-54-31 refers.\n\n    5. For aircraft serial numbers 3 through 369, install Modification 8/2001 (Nacelles/Pylons \\- Cowl Door Seal Improvement). De Havilland SB 8-71-19 Revision B refers.\n\nNote: Transport Canada AD CF-94-10R1 refers.\n\nCompliance: Unless already accomplished, prior to 31 August 1995.\n\nBackground: Three incidents of DHC-8 nacelle fuel leaks have resulted in an explosive ignition with subsequent damage to the engine cowling. Transport Canada requires incorporation of certain modifications which are designed to minimise the chance of a nacelle fire, through better sealing in the engine nacelle area. Amendment 1 is issued in response to a revision of the related Transport Canada AD which extends the applicability and references a later revision of the document for Requirement 5.","sortOrder":0}],"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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":true,"description":"This is Amendment 1 to an existing directive. Compared to the original AD/DHC-8/35, this version expanded the applicability: Requirement 5 now covers aircraft serial numbers up to 369 (extended from an earlier lower number), and references a later revision of the technical document (De Havilland SB 8-71-19 Revision B). This reflects the typical evolution of airworthiness directives where operational experience reveals the need for broader application of safety modifications."},"complexity_factors":["Single-purpose technical directive with only 5 specific requirements","Minimal defined terms (only standard aviation terminology like 'Modification' and 'Service Bulletin')","No nested conditional logic—each requirement applies to a clear, non-overlapping serial number range","Simple compliance deadline with single exception ('Unless already accomplished')","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998 and related Canadian authority","Total length is approximately 250 words"],"plain_english_summary":"This Airworthiness Directive orders five specific nacelle modifications on Bombardier/De Havilland DHC‑8 Series 100 and 300 aircraft (serials 3–369) to improve sealing and fireproofing and prevent fuel leaks and engine‑nacelle fires. It affects owners and operators of those aircraft and cites manufacturer Service Bulletins as the means of compliance.\n\nIssued after three nacelle fuel‑leak/ignition incidents, Amendment 1 broadened the scope and updated technical references; the compliance deadline was 31 August 1995."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Amendment 1 expands the directive's applicability to additional serial‑number ranges and updates the referenced service bulletin for Requirement 5, aligning this AD with a revised Transport Canada AD."},"complexity_factors":["Multiple distinct modification requirements (five separate mods) across overlapping serial‑number ranges","Cross‑references to several De Havilland service bulletins and to a Transport Canada AD for technical detail","Single fixed retrospective compliance date (31 August 1995) requiring catch‑up work and scheduling of maintenance","Administrative burden to verify applicability by serial number and to record compliance in maintenance logs","Potential supply, parts and labour coordination to implement structural/sealing changes on nacelles","Amendment updates applicability and a service bulletin reference, creating a versioning/traceability task for maintainers"],"plain_english_summary":"This Airworthiness Directive requires operators of Bombardier (De Havilland) DHC‑8 Series 100 and 300 aeroplanes (specified serial ranges) to install five nacelle sealing and fireproofing modifications using the listed De Havilland service bulletins, with compliance by 31 August 1995.\n\nThe AD says the changes reduce the chance of fuel‑leak ignition after three incidents. Costs, parts, labour and downtime fall on aircraft operators, who must record the work; Amendment 1 broadens applicability and updates the reference for Requirement 5."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-35-amdt-1-engine-nacelle","history":"/api/acts/ad-dhc-8-35-amdt-1-engine-nacelle/history","analysis":"/api/acts/ad-dhc-8-35-amdt-1-engine-nacelle/analysis","conflicts":"/api/acts/ad-dhc-8-35-amdt-1-engine-nacelle/conflicts","importantCases":"/api/acts/ad-dhc-8-35-amdt-1-engine-nacelle/important-cases","documents":"/api/acts/ad-dhc-8-35-amdt-1-engine-nacelle/documents"}}