{"id":"F2006B09086","name":"AD/DHC-3/36 - Fire Detection and Extinguishing System","slug":"ad-dhc-3-36-fire-detection-and-extinguishing-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115639,"registerId":"commonwealth-F2006B09086-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-3/36 - Fire Detection and Extinguishing System","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)  \nDHC-3 (Otter) Series Aeroplanes\n\nAD/DHC-3/36 Fire Detection and Extinguishing System 6/99\n\nApplicability: All Model DHC-3 ‘Otter’ aeroplanes powered by Pratt and Whitney reciprocating, nine cylinder, radial, air-cooled engines.\n\nRequirement: 1. Inspect the fire extinguishing system (FIREX) in accordance with the DHC-3 Maintenance Manual, PSM 1-3-2, pages 122 and 122A (revised\n\n15 September 1963), paragraph 4.11.4.\n\n    2. If, during the Requirement 1 inspection, the FIREX is found to be unserviceable, either repair the system or replace it with a serviceable approved system.\n\n    3. Determine if the fire detection system (FIRDET) is time-expired by making reference to the appropriate Graviner Ltd literature such as Maintenance Leaflet ML 066 dated April 1981.\n\n    4. If, as a result of the Requirement 3 determination, the FIRDET is found to be time- expired, replace it with a serviceable approved system.\n\n    5. For aeroplanes that have had the FIREX and/or FIRDET removed, replace the missing system(s), as applicable, by installing an approved serviceable FIREX and/or FIRDET.\n\nNote 1: Transport Canada Civil Aviation AD CF-99-06 refers.\n\nNote 2: This Directive supersedes and cancels any approval granted by a modification approved under Civil Aviation Regulation 35 or in any Supplemental Type Certificate or equivalent document that authorises the removal of the FIREX and/or FIRDET.\n\nCompliance: 1. Within 60 days after the effective date of this Directive.\n\n    2. No later than 30 April 2000.\n\n    3. Within 60 days after the effective date of this Directive.\n\n    4. No later than 30 April 2000.\n\n    5. No later than 30 April 2000.\n\nThis Airworthiness Directive becomes effective on 17 June 1999.\n\nBackground: Transport Canada Civil Aviation has advised that the initial type approval for the DHC-3 aircraft was ICAO Annex 8, 2nd Edition (Transport Category D) which specifies fire detecting and extinguishing provisions. Maintaining a serviceable fire detection system has proved difficult, primarily due to the fire detection sensing element having been time expired, replacement unavailable and no available approved substitute. A few approvals were previously granted by Transport Canada to authorise the removal of the fire detection and extinguishing system.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nThis Directive has been issued to provide a temporary alleviation for those aeroplanes that are out of compliance with the DHC-3 type approval basis due to the FIREX and/or FIRDET systems being inoperative, time expired or having previously been granted permission to remove the fire detection and extinguishing system.","sortOrder":0}],"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow scope — addressing fire safety systems on a specific vintage aircraft type. The background explains that it provides 'temporary alleviation' for non-compliant aircraft, but this is actually tightening standards (requiring reinstallation of removed systems) rather than expanding beyond aviation safety into new domains."},"complexity_factors":["Single aircraft type and engine combination specified (narrow applicability)","Five numbered requirements with clear conditional logic ('if found unserviceable, then repair or replace')","Multiple compliance dates that must be cross-referenced against effective date","References to external technical documents (DHC-3 Maintenance Manual PSM 1-3-2, Graviner ML 066) that are not reproduced in the directive","Cancellation of prior regulatory approvals (modifications under CAR 35, Supplemental Type Certificates) creates a nested exception — removing an exception","Background section explains regulatory history (ICAO Annex 8, Transport Canada approvals) but is informational rather than operative"],"plain_english_summary":"This mandatory CASA Airworthiness Directive requires owners/operators of DHC‑3 “Otter” aeroplanes with Pratt & Whitney radial engines to inspect, repair, replace or reinstall engine fire detection and extinguishing systems where unserviceable, expired, or previously removed.  \n\nInspections must be done within 60 days of 17 June 1999, with all corrective work completed by 30 April 2000. It closes a safety gap allowing operation without fire protection and addresses the severe risk of engine fire."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"The Directive restores and enforces the original type-approval requirement for onboard fire detection and extinguishing equipment by mandating inspection, replacement or reinstallation and by cancelling previous approvals that allowed removal. It thus removes exemptions that had narrowed scope and re-expands mandatory equipment obligations for affected DHC‑3 operators."},"complexity_factors":["Cross-references to external maintenance publications and manufacturer literature: DHC-3 Maintenance Manual PSM 1-3-2 (pages 122 and 122A, para 4.11.4) (Requirement 1) and Graviner Maintenance Leaflet ML 066 (April 1981) (Requirement 3).","Multiple specified actions and choices for operators: inspect, determine time-expiry, repair, replace, or reinstall systems (Requirements 1–5).","Staggered compliance deadlines (60 days after effective date for some actions; no later than 30 April 2000 for others), creating scheduling and resource constraints (Compliance).","Applicability narrowly targeted to all Model DHC-3 aeroplanes with Pratt & Whitney nine‑cylinder radial engines — concentrates obligations on a defined owner/operator group (Applicability).","Legal effect on prior approvals: supersedes and cancels previously granted permissions (modifications under CAR 35, Supplemental Type Certificates or equivalent) to remove FIREX and/or FIRDET (Note 2), changing the legal compliance landscape for affected aircraft.","Background admission of limited parts availability and time-expired sensing elements increases implementation risk and potential cost for sourcing approved serviceable replacements (Background).","Cross-border regulatory linkage: references Transport Canada AD CF-99-06 and ICAO Annex 8 type-approval basis, requiring alignment with international certification history (Background/Note 1)."],"plain_english_summary":"This Directive requires owners/operators of DHC‑3 “Otter” aeroplanes (Pratt & Whitney radial engines) to inspect, and where necessary repair or replace, the aircraft fire detection (FIRDET) and extinguishing (FIREX) systems in line with the type maintenance literature. \n\nIt imposes short compliance deadlines, mandates reinstalling any previously removed systems, and cancels earlier approvals that allowed removal — creating a direct compliance and maintenance cost for operators while restoring the original type‑approval equipment requirements."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-3-36-fire-detection-and-extinguishing-system","history":"/api/acts/ad-dhc-3-36-fire-detection-and-extinguishing-system/history","analysis":"/api/acts/ad-dhc-3-36-fire-detection-and-extinguishing-system/analysis","conflicts":"/api/acts/ad-dhc-3-36-fire-detection-and-extinguishing-system/conflicts","importantCases":"/api/acts/ad-dhc-3-36-fire-detection-and-extinguishing-system/important-cases","documents":"/api/acts/ad-dhc-3-36-fire-detection-and-extinguishing-system/documents"}}