{"id":"F2008L00140","name":"AD/DHC-8/136 - Fuel System Safety - Maintenance Tasks","slug":"ad-dhc-8-136-fuel-system-safety-maintenance-tasks","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":72278,"registerId":"commonwealth-F2008L00140-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Bombardier (Boeing Canada/De Havilland) ","sectionType":"division","heading":"Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes","content":"### Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes\n\n| AD/DHC-8/136 | Fuel System Safety - Maintenance Tasks | 3/2008 DM |\n| ------------ | -------------------------------------- | --------- |\n\n| Applicability: | Models DHC-8-400, DHC-8-401, DHC-8-402 aircraft, all serial numbers.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Revise the approved maintenance schedule by incorporating all Fuel System Limitations (FSL) tasks contained in Temporary Revision (TR) ALI-69 of DHC-8-400 Maintenance Requirements Manual, 1-84-7, Part 2 “Airworthiness Limitation Items”.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |\n|                | Note: Transport Canada AD CF-2007-33 refers.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |\n| Compliance:    | Within 60 days after the effective date of this Directive.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |\n|                | This Airworthiness Directive becomes effective on 31 January 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n| Background:    | Bombardier Aerospace has completed a system safety review of the aircraft fuel system against fuel tank safety standards introduced in Chapter 525 of the Airworthiness Manual through Notice of Proposed Amendment (NPA) 2002-043. The identified non-compliances were then assessed using Transport Canada Policy Letter No. 525-001, to determine if mandatory corrective action is required.The assessment showed that supplemental maintenance tasks are required to prevent potential ignition sources within the fuel system, which could result in a fuel tank explosion. Revisions have been made to Part 2 “Airworthiness Limitations List” of the DHC-8-400 Maintenance Program Manuals to introduce the required maintenance tasks. |\n\n![](image.001.png)  \nCharles Lenarcic  \nDelegate of the Civil Aviation Safety Authority\n\n16 January 2008","sortOrder":0},{"sectionNumber":"AD/DHC-8/136","sectionType":"part","heading":"AD/DHC-8/136","content":"## AD/DHC-8/136","sortOrder":1},{"sectionNumber":"Fuel System Safety - Maintenance Tasks","sectionType":"part","heading":"Fuel System Safety - Maintenance Tasks","content":"## Fuel System Safety - Maintenance Tasks","sortOrder":2},{"sectionNumber":"3/2008 DM","sectionType":"part","heading":"3/2008 DM","content":"## 3/2008 DM","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope: mandating specific fuel system maintenance tasks for the DHC-8-400 series following a manufacturer safety review. The directive does not expand beyond its initial purpose of addressing identified ignition source risks in the fuel system."},"complexity_factors":["Single, specific technical requirement (incorporate one Temporary Revision to one manual)","No defined terms section — uses standard aviation terminology (FSL, TR, ALI) with context provided","No nested exceptions or conditional logic","Clear, unambiguous applicability (three specific model variants, all serial numbers)","Single compliance deadline with no alternative methods or phased implementation","Cross-reference to Canadian regulation is informational only, not a dependency for understanding the requirement"],"plain_english_summary":"This CASA Airworthiness Directive requires operators of Bombardier DHC-8-400/-401/-402 (Q400) aircraft to amend maintenance manuals to include Fuel System Limitations (FSL) tasks. It affects airlines, maintenance crews and Australian-registered Q400s to prevent ignition sources inside fuel tanks that could cause explosions. Operators had 60 days from 31 January 2008 to comply, aligning Australia with Transport Canada’s directive."},"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 remains focused on its original purpose: addressing identified fuel system non-compliances by adding airworthiness limitation (maintenance) tasks to prevent potential ignition sources in fuel tanks. It does not expand the regulatory approach beyond that narrow corrective action (no new design mandates, no expanded applicability beyond the specified models and serial numbers), so the scope has not grown beyond its original safety-focused intent."},"complexity_factors":["Single substantive requirement (revise maintenance schedule to include FSL tasks from TR ALI-69).","Short, self-contained directive (few sections and limited conditions).","Cross-references to external documents: Temporary Revision ALI-69, DHC-8-400 Maintenance Requirements Manual Part 2, Transport Canada AD CF-2007-33, NPA 2002-043, and Policy Letter No. 525-001 (adds administrative complexity for implementers).","Clear 60‑day compliance deadline and specified effective date. ","Applies to three model variants (DHC-8-400/401/402), all serial numbers (broad applicability but simple coverage).","No nested exceptions, no alternate means of compliance specified in text (reduces internal conditionality)."],"plain_english_summary":"**What this directive does (mechanically)**\n\n- Requires operators of Bombardier (De Havilland) DHC-8-400/401/402 series aeroplanes (all serial numbers) to revise their approved maintenance schedule to include the Fuel System Limitations (FSL) tasks listed in Temporary Revision ALI-69 to the DHC-8-400 Maintenance Requirements Manual, Part 2 (“Airworthiness Limitation Items”).\n- Compliance must be completed within 60 days of the directive taking effect (effective date: 31 January 2008).\n- The directive cross-references Transport Canada AD CF-2007-33 and is based on Bombardier’s fuel system safety review and Transport Canada’s assessment.\n\n**Who it affects**\n\n- Aircraft owners and operators of the DHC-8-400/401/402 series.\n- Approved maintenance organisations and certificated engineers who maintain those aircraft and who must carry out or schedule the new maintenance tasks and record them in the maintenance programme.\n\n**Why it matters (stated purpose and practical effect)**\n\n- Stated purpose: Bombardier’s system safety review against updated fuel tank safety standards (Airworthiness Manual Chapter 525 via NPA 2002-043) identified non-compliances. Transport Canada’s policy assessment found supplemental maintenance tasks were required to prevent potential ignition sources within the fuel system, which could lead to a fuel tank explosion.\n- Practical effect: operators must amend their Airworthiness Limitation Items (ALI) to add specified inspections and maintenance tasks. That leads to additional scheduled maintenance work, record-keeping, and possible aircraft downtime.\n\n**Costs, incentives and trade-offs (how it affects private parties and choices)**\n\n- Who pays: aircraft operators pay the direct costs — labour, parts, and any increased downtime — of implementing and performing the added maintenance tasks and of updating maintenance documentation.\n- Who decides: the Civil Aviation Safety Authority (via this directive) mandates the change; operators decide precisely how to schedule and resource the tasks within the 60‑day compliance window, subject to approval/oversight where required by maintenance certification rules.\n- Behaviour change: maintenance programmes and their task intervals will change; maintenance organisations will perform additional inspections or actions specified in the TR. Operators may re-sequence other checks to reduce downtime.\n- Trade-offs and opportunity costs: resources (hangar time, skilled labour) must be diverted to perform the new tasks, potentially increasing operating costs and reducing aircraft availability. The directive does not itself prescribe alternative means of compliance in the text provided, so operators must follow the TR or seek an approved alternative process if available under regulatory practice.\n- Implementation risk and compliance burden: the primary burden is administrative (revising the approved maintenance schedule) and operational (performing the tasks). There is modest regulatory discretion because the directive references a specific temporary revision (ALI-69); any departure would typically require formal approval from the regulator.\n\n**Other practical notes**\n\n- The directive is narrow in scope: it does not mandate design changes or retrofits, but prescribes changes to the maintenance programme (Airworthiness Limitation Items).\n- It aligns with a Transport Canada airworthiness directive, indicating harmonisation with the certifying authority’s safety assessment."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-136-fuel-system-safety-maintenance-tasks","history":"/api/acts/ad-dhc-8-136-fuel-system-safety-maintenance-tasks/history","analysis":"/api/acts/ad-dhc-8-136-fuel-system-safety-maintenance-tasks/analysis","conflicts":"/api/acts/ad-dhc-8-136-fuel-system-safety-maintenance-tasks/conflicts","importantCases":"/api/acts/ad-dhc-8-136-fuel-system-safety-maintenance-tasks/important-cases","documents":"/api/acts/ad-dhc-8-136-fuel-system-safety-maintenance-tasks/documents"}}