{"id":"F2006B09179","name":"AD/DHC-8/24 - Fuel Heater Low Fuel Pressure Switch Adapter/Snubber and Engine Nacelle Sealing","slug":"ad-dhc-8-24-fuel-heater-low-fuel-pressure-switch-adapter-snubber-and-engine-nacelle-sealing","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52942,"registerId":"commonwealth-F2006B09179-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-8/24 - Fuel Heater Low Fuel Pressure Switch Adapter/Snubber and Engine Nacelle Sealing","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-8/24 Fuel Heater Low Fuel Pressure Switch\n\nAdapter/Snubber and Engine Nacelle Sealing\n\nApplicability: DHC-8-102, \\-103, \\-301, and 311 Series.\n\nRequirement: Action IAW the technical requirements of the FAA AD 92-13-11.\n\n  \n13/92\n\nDM\n\nNote: Transport Canada Airworthiness Directive CF-92-12; All Operator Messages 131, 138 and 152; and Alert Service Bulletin A8-73-14 refer.\n\nCompliance: As detailed in the Requirement Document with an effective date of 4 November 1992.\n\nBackground: Investigation into an incident involving a nacelle fire indicated that overtorquing and improper seating contributed to the failure of the fuel heater low pressure switch adapter/snubber resulting in a fuel leak in the nacelle.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The instrument does not indicate a change in scope from the action it prescribes. It applies to the specified DHC-8 series and mandates the corrective actions set out in FAA AD 92-13-11 to address the failure mode identified in the investigation (Applicability; Requirement; Background). The AD is framed as an implementing directive rather than an expansion or narrowing of scope beyond those aircraft and the referenced corrective measures (Requirement; Compliance)."},"complexity_factors":["Cross-reference to an external FAA Airworthiness Directive (FAA AD 92-13-11) rather than containing full technical steps in the text (Requirement).","Additional referenced materials listed (Transport Canada AD CF-92-12; All Operator Messages 131, 138 and 152; Alert Service Bulletin A8-73-14) which operators may need to consult to implement corrective actions (Note).","Applicability limited to several specific DHC-8 variants, requiring accurate applicability checking by operators (Applicability).","Technical maintenance tasks (inspection, torque/seating checks, nacelle sealing) implied by the Background and Requirement — these tasks require skilled maintenance labour and appropriate parts/tools (Background; Requirement).","A fixed compliance effective date that creates a timing constraint for operators (Compliance)."],"plain_english_summary":"This AD mandates operators and maintenance organisations of DHC‑8‑102/103/301/311 aeroplanes to carry out the corrective inspections and repairs set out in FAA AD 92‑13‑11—specifically addressing the fuel heater low fuel pressure switch adapter/snubber and nacelle sealing—to remove a failure mode linked to a nacelle fire caused by overtorquing/improper seating and resultant fuel leak. Compliance is compulsory under the Australian AD (effective 4 Nov 1992); operators bear inspection, repair, parts and downtime costs and must follow the FAA‑prescribed methods."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete, incident-responsive safety directive. It addresses a specific mechanical failure mode identified through accident investigation and mandates a targeted fix. The scope remains tightly focused on the original safety issue without expansion into unrelated systems or aircraft types."},"complexity_factors":["Very short document (under 200 words)","Only 4 defined aircraft model variants in applicability section","Single technical requirement referencing external FAA document rather than spelling out procedures","No nested exceptions or conditional logic — compliance is mandatory and straightforward","Background is narrative explanation rather than legal cross-referencing"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order for aircraft owners and operators. It requires specific fixes to certain **Bombardier DHC-8 aircraft** (also known as Dash 8s, specifically the -102, -103, -301, and -311 models).\n\n**What the problem is:**\nA nacelle fire incident was investigated and found to be caused by a faulty **fuel heater low pressure switch adapter/snubber** — a small component that helps monitor fuel pressure. When this part was overtightened or improperly installed, it could fail and leak fuel into the engine nacelle (the housing around the engine), creating a fire risk.\n\n**What must be done:**\nAircraft operators must follow the technical instructions in **FAA AD 92-13-11** (an American aviation safety order) to inspect and fix the fuel heater component and ensure proper **engine nacelle sealing** (making sure the engine housing is properly closed up to prevent fuel leaks).\n\n**Who this affects:**\n- Owners and operators of specific DHC-8 aircraft models\n- Maintenance engineers working on these aircraft\n- Airlines using these Dash 8 variants\n\n**Why it matters:**\nFuel leaks near engines can cause catastrophic fires. This directive prevents that by mandating a proven fix developed after an actual incident."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-24-fuel-heater-low-fuel-pressure-switch-adapter-snubber-and-engine-nacelle-sealing","history":"/api/acts/ad-dhc-8-24-fuel-heater-low-fuel-pressure-switch-adapter-snubber-and-engine-nacelle-sealing/history","analysis":"/api/acts/ad-dhc-8-24-fuel-heater-low-fuel-pressure-switch-adapter-snubber-and-engine-nacelle-sealing/analysis","conflicts":"/api/acts/ad-dhc-8-24-fuel-heater-low-fuel-pressure-switch-adapter-snubber-and-engine-nacelle-sealing/conflicts","importantCases":"/api/acts/ad-dhc-8-24-fuel-heater-low-fuel-pressure-switch-adapter-snubber-and-engine-nacelle-sealing/important-cases","documents":"/api/acts/ad-dhc-8-24-fuel-heater-low-fuel-pressure-switch-adapter-snubber-and-engine-nacelle-sealing/documents"}}