{"id":"F2006B01798","name":"AD/A109/14 - Main Landing Gear Wheels","slug":"ad-a109-14-main-landing-gear-wheels","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":40996,"registerId":"commonwealth-F2006B01798-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/A109/14 - Main Landing Gear Wheels","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-description: CASA Airworthiness Directive\nmeta-generator: Aspose.Words for .NET 22.10.0\nmeta-keywords: Issue 13/1988,Rotorcraft,Agusta A109 Series Helicopters,Main Landing Gear Wheels,14\ntitle: Airworthiness Directive - AD/A109/14 - Main Landing Gear Wheels\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)  Agusta A109 Series Helicopters\n\n \n\nAD/A109/14 Main Landing Gear Wheels 13/88\n\nApplicability: A109A and A109AII.\n\n \n\nRequirement: Action in accordance with Bollettino Tecnico 109-71.\n\n \n\nNote: RAI AD 88-142 refers.\n\n \n\nCompliance: Before 30 March 1989.\n\n \n\nBackground: Excessive torque on the retaining nut has caused failure of the aluminium retaining washer and loss of the wheel.\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":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive's scope is limited and targeted: it applies only to Agusta A109A and A109AII helicopters and requires the actions specified in Bollettino Tecnico 109-71 to mitigate retaining washer failure and potential wheel loss. The textual material provided shows no expansion or narrowing beyond that original targeted safety intervention (Applicability; Requirement; Background)."},"complexity_factors":["Narrow applicability limited to two Agusta A109 models (A109A and A109AII) (Applicability)","Single mandatory action but technical details are delegated to an external document (Bollettino Tecnico 109-71), which increases practical complexity for implementers (Requirement)","Fixed compliance deadline creates scheduling and operational constraints (Compliance)","Safety-critical subject matter raises implementation risk if instructions are misunderstood or improperly executed (Background)","Cross-reference to another directive (RAI AD 88-142) requires consult of multiple documents (Note)"],"plain_english_summary":"What this directive does (mechanics)\n\n- The Civil Aviation Safety Authority (CASA) requires owners/operators of Agusta A109 helicopters of models A109A and A109AII to carry out the maintenance action set out in Bollettino Tecnico 109-71. (Requirement; Applicability)\n- The work must be completed before 30 March 1989. (Compliance)\n\nWho this affects\n\n- Aircraft owners and operators of Agusta A109A and A109AII helicopters. (Applicability)\n- People or businesses who perform helicopter maintenance for those helicopters, because they will be asked to perform whatever task Bollettino Tecnico 109-71 specifies. (Requirement)\n\nWhy the directive was issued (official rationale)\n\n- CASA states the directive responds to incidents where excessive torque on a retaining nut caused the aluminium retaining washer to fail and a wheel to be lost. The Bollettino is the prescribed corrective or preventive action. (Background; Requirement)\n\nPractical consequences, incentives and trade-offs\n\n- Who pays: Operators/owners will bear the direct cost of complying with the directive because they must implement the Bollettino's instructions by the compliance date. (Requirement; Compliance)\n- What must change: Operators must arrange the specified inspections, adjustments, repairs or replacements contained in Bollettino Tecnico 109-71. The AD itself defers technical detail to that Bollettino. (Requirement)\n- Timing and operational cost: The fixed deadline (before 30 March 1989) creates a window in which maintenance, part replacement or inspections must be scheduled, causing aircraft downtime and use of maintenance resources. (Compliance)\n- Compliance burden and implementation risk: The AD is safety-motivated; failing to comply leaves the underlying mechanical risk (retaining washer failure and wheel loss) unaddressed. The Bollettino will determine the technical scope and therefore the labour, parts and certification steps required. (Background; Requirement)\n- Decision authority and discretion: The AD prescribes following the Bollettino but does not itself set technical tolerances; it directs operators to implement the external technical document. That concentrates regulatory command on CASA to require the action and on the Bollettino author to set the technical method, while operators decide how (in-house or contracted maintenance) to meet it. (Requirement)\n- Effects on maintenance market and choice: Because operators must have the Bollettino work done, there is demand for maintenance services; operators can choose service providers or use their own maintenance capability subject to applicable aviation maintenance standards. The AD does not, in its text, restrict which certified maintenance organisation may perform the work. (Requirement)\n\nImplementation note\n\n- The AD references another directive (RAI AD 88-142) for related material. Operators should consult Bollettino Tecnico 109-71 and the referenced AD for full technical and procedural requirements. (Note; Requirement)\n\nBottom line\n\n- Mechanically, the AD mandates a specific maintenance action (as detailed in Bollettino 109-71) for Agusta A109A and A109AII helicopters to address a known failure mode (excessive torque causing retaining washer failure and wheel loss). It sets a firm compliance deadline, shifting the practical costs and scheduling decisions to operators and maintenance providers. (Applicability; Requirement; Compliance; Background)"},"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 specific helicopter models. It has not expanded beyond its original purpose of mandating a wheel inspection/fix."},"complexity_factors":["Extremely short document (under 200 words)","Only 2 defined applicability criteria (A109A and A109AII models)","Single requirement referencing an external technical document rather than spelling out detailed steps","No nested exceptions, conditional logic, or internal cross-references","Simple linear structure: applicability → requirement → compliance date → background","Minimal legislative drafting — essentially a safety notice format"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA). Think of it as a mandatory safety recall for aircraft — but instead of cars, it's for helicopters.\n\n**What it does:** It requires owners and operators of specific Agusta A109 helicopters (the A109A and A109AII models) to take corrective action on their main landing gear wheels. Specifically, they must follow the instructions in a technical bulletin called \"Bollettino Tecnico 109-71\" (an official document from the helicopter manufacturer).\n\n**Why it matters:** The wheels could fail. The problem is that if mechanics tighten the retaining nut too much (excessive torque), it can break the aluminium washer that holds the wheel in place. If that washer fails, the wheel can fall off — obviously catastrophic for a helicopter.\n\n**Who must act:** Anyone operating the affected helicopter models in Australia.\n\n**Deadline:** The fix had to be completed before 30 March 1989.\n\n**Cross-reference:** This aligns with a US Federal Aviation Administration directive (RAI AD 88-142), showing this was a known international safety issue."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a109-14-main-landing-gear-wheels","history":"/api/acts/ad-a109-14-main-landing-gear-wheels/history","analysis":"/api/acts/ad-a109-14-main-landing-gear-wheels/analysis","conflicts":"/api/acts/ad-a109-14-main-landing-gear-wheels/conflicts","importantCases":"/api/acts/ad-a109-14-main-landing-gear-wheels/important-cases","documents":"/api/acts/ad-a109-14-main-landing-gear-wheels/documents"}}