{"id":"F2006B03952","name":"AD/BEECH 50/28 - Wheel Well Fuel Lines","slug":"ad-beech-50-28-wheel-well-fuel-lines","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43561,"registerId":"commonwealth-F2006B03952-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEECH 50/28 - Wheel Well Fuel Lines","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)  \nBeechcraft 50 (Twin Bonanza) Series Aeroplanes\n\nAD/BEECH 50/28 Wheel Well Fuel Lines 4/79\n\nApplicability: All models.\n\nRequirement: Replace all aluminium fuel lines upstream of the fuel selector valve in each main landing gear wheel well with lines fabricated from stainless steel.\n\nNote: This requirement does not include the large diameter fuel tank interconnect line situated in the aft section of the wheel wells.\n\nCompliance: Before 1 July 1979.\n\nBackground: In the event of an uncontained engine compartment fire it is known that flames will be directed by the slipstream into the main landing gear wheel wells, through which unprotected aluminium fuel lines of small diameter are located. Should any line burn through upstream of the fuel selector valve an uncontrollable amount of fuel will be added to the fire and the integrity of the wing main spar will be endangered. In order to reduce this threat, the aluminium fuel lines are to be replaced with those of stainless steel.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive focused specifically on fuel line replacement in one aircraft type. It has not expanded beyond its original narrow technical purpose."},"complexity_factors":["Very short document (under 200 words)","Only 1 defined term implicitly understood ('uncontained engine compartment fire' — explained in plain language in the Background)","Single, unambiguous requirement with one clear exception noted","No cross-references to other legislation or regulations beyond the enabling authority (Civil Aviation Regulations 1998, Part 39)","No conditional logic or nested exceptions — just one straightforward replacement task with a simple carve-out for the large diameter interconnect line"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). Think of it as a \"recall notice\" for aircraft, but legally binding.\n\n**What it does:** It orders owners and operators of Beechcraft 50 \"Twin Bonanza\" aircraft to replace certain fuel pipes in the main landing gear wheel wells. Specifically, all small aluminium fuel lines located *before* the fuel selector valve must be swapped out for stainless steel versions.\n\n**Why:** If there's an engine fire, flames can get blown back into the wheel wells by the airflow around the plane. The original aluminium fuel lines can burn through, causing fuel to pour onto the fire and potentially weakening the wing's main structural beam (the \"main spar\"). Stainless steel lines are much harder to burn through, so this reduces the risk of a catastrophic fire.\n\n**Who it affects:** Anyone who owns or operates a Beechcraft 50 series aircraft (all models).\n\n**What's excluded:** The big fuel pipe that connects the fuel tanks together at the back of the wheel well doesn't need to be replaced.\n\n**When it had to be done:** Before 1 July 1979 (this is a historical directive from 1979)."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument sets a single, safety‑driven replacement requirement with a specific exclusion and a compliance date. The text shows no amendment or scope expansion beyond that stated purpose; therefore there is no evident change from the directive's stated scope."},"complexity_factors":["Single, narrowly framed technical action: replace aluminium lines with stainless steel (Requirement) — straightforward mandate.","Fleet-wide applicability to all Beechcraft 50 models (Applicability) increases operational scale of compliance.","Technical location specified as 'upstream of the fuel selector valve' (Requirement) requires maintenance judgment to identify affected runs.","Explicit exclusion of the large‑diameter tank interconnect (Note) creates a boundary that implementers must observe.","Fixed compliance date (before 1 July 1979) imposes a hard rollout schedule (Compliance).","Safety‑critical justification (Background) implies certified workmanship and possible parts‑sourcing burdens; no methods, materials specifications or cost allocation are provided (Requirement/Note), leaving practical implementation decisions to operators/maintainers."],"plain_english_summary":"Replaces all small aluminium fuel lines upstream of the fuel‑selector valve in each main landing‑gear wheel well on Beechcraft 50 (Twin Bonanza) aeroplanes with stainless‑steel lines (Requirement). The rule applies to all models (Applicability), excludes the large‑diameter tank interconnect (Note), and had to be completed by 1 July 1979 (Compliance). The stated aim is to reduce the risk that wheel‑well line burn‑through during an engine‑compartment fire will feed uncontrolled fuel to the fire and threaten the wing main spar (Background)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-50-28-wheel-well-fuel-lines","history":"/api/acts/ad-beech-50-28-wheel-well-fuel-lines/history","analysis":"/api/acts/ad-beech-50-28-wheel-well-fuel-lines/analysis","conflicts":"/api/acts/ad-beech-50-28-wheel-well-fuel-lines/conflicts","importantCases":"/api/acts/ad-beech-50-28-wheel-well-fuel-lines/important-cases","documents":"/api/acts/ad-beech-50-28-wheel-well-fuel-lines/documents"}}