{"id":"F2006B09188","name":"AD/DHC-8/32 - Landing Gear Hydraulic Selector Valve","slug":"ad-dhc-8-32-landing-gear-hydraulic-selector-valve","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52982,"registerId":"commonwealth-F2006B09188-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-8/32 - Landing Gear Hydraulic Selector Valve","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes\n\n \n\nAD/DHC-8/32 Landing Gear Hydraulic Selector Valve 7/94\n\nApplicability: All DHC-8-100 series aircraft S/N 003 through 038 not incorporating modification 8/0530.\n\n \n\nRequirement: Unless previously carried out action in accordance with de HAVILLAND Dash 8 Alert Service Bulletin A8-32-117.\n\n \n\nNote: Transport Canada AD CF-94-05 refers.\n\n \n\nCompliance: Within 300 hours time in service from 30 June 1994 or by 30 October 1994, whichever occurs first.\n\n \n\nBackground: The manufacturer has advised that pilot valve leakage which has not been corrected may, when combined with a low voltage condition, lead to an inadvertent landing gear retraction.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive addressing a specific mechanical defect in a limited fleet. It has not expanded beyond its original purpose of mandating a manufacturer-recommended fix for a identified safety hazard."},"complexity_factors":["Single, specific technical requirement referencing an external manufacturer bulletin rather than spelling out procedures","Narrow applicability: only 36 specific aircraft serial numbers (003-038) excluding those with one specific modification","Simple compliance deadline structure: two alternative triggers (flight hours or calendar date), take the earlier","No defined terms section, no cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Single background explanation with clear causal chain (leakage + low voltage = inadvertent retraction)","Total length: approximately 150 words of substantive content"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nOrders owners and operators of certain Bombardier DHC-8-100 series aeroplanes (turboprop regional airliners, also known as Dash 8s) to inspect and fix a potentially dangerous fault in the landing gear hydraulic system.\n\n**Who it affects:**\n- **Aircraft affected:** DHC-8-100 series planes with serial numbers 003 through 038 that haven't already had a specific factory modification (modification 8/0530) installed.\n- **People affected:** Airlines, charter operators, and private owners flying these specific aircraft in Australia.\n\n**The safety problem:**\nThe manufacturer discovered that if the pilot valve in the landing gear hydraulic selector leaks *and* there's a low electrical voltage condition at the same time, the landing gear could accidentally retract while the plane is on the ground. This could cause the aircraft to collapse onto its belly, potentially injuring people and damaging the plane.\n\n**What must be done:**\nOperators must follow the repair instructions in **de Havilland Alert Service Bulletin A8-32-117** — a technical notice from the manufacturer describing the inspection and fix.\n\n**When it must be done:**\nWithin 300 flight hours after 30 June 1994, **or** by 30 October 1994 — whichever comes first.\n\n**Why it matters:**\nThis is a classic aviation safety intervention. It catches a rare but catastrophic failure mode (two minor faults combining to cause a major accident) before it happens. The short compliance window (about 4 months maximum) reflects the seriousness of the risk."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive, as written, imposes a corrective maintenance action on a defined subset of DHC-8-100 aircraft (S/N 003–038) that have not incorporated modification 8/0530 and sets a clear compliance deadline (Applicability; Requirement; Compliance). The text does not indicate any expansion or narrowing of that scope beyond those stated limits, so there is no evidence in this document that the scope was changed from the directive’s stated intent."},"complexity_factors":["Narrow applicability limited to specific serial numbers (Applicability).","Dependency on whether modification 8/0530 has been incorporated (Applicability).","Mandatory compliance tied to a manufacturer alert service bulletin rather than detailed steps in the AD (Requirement).","A firm, time-limited compliance window (300 hours or by 30 Oct 1994) creates scheduling constraints (Compliance).","Technical nature of the safety issue (hydraulic selector valve leakage interacting with low electrical voltage) requires qualified maintenance action (Background)."],"plain_english_summary":"This airworthiness directive requires operators of de Havilland DHC‑8‑100 aeroplanes (serials 003–038) that have not installed modification 8/0530 to carry out the work specified in de Havilland Alert Service Bulletin A8‑32‑117 within 300 flight hours of 30 June 1994 or by 30 October 1994, to fix a pilot‑valve leak risk that could permit inadvertent landing‑gear retraction. Costs and scheduling fall to the aircraft owners/operators; CASA enforces the directive."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-32-landing-gear-hydraulic-selector-valve","history":"/api/acts/ad-dhc-8-32-landing-gear-hydraulic-selector-valve/history","analysis":"/api/acts/ad-dhc-8-32-landing-gear-hydraulic-selector-valve/analysis","conflicts":"/api/acts/ad-dhc-8-32-landing-gear-hydraulic-selector-valve/conflicts","importantCases":"/api/acts/ad-dhc-8-32-landing-gear-hydraulic-selector-valve/important-cases","documents":"/api/acts/ad-dhc-8-32-landing-gear-hydraulic-selector-valve/documents"}}