{"id":"F2006B10543","name":"AD/HS 748/1 - Landing Gear Selector Lever Assembly","slug":"ad-hs-748-1-landing-gear-selector-lever-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116349,"registerId":"commonwealth-F2006B10543-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 748/1 - Landing Gear Selector Lever Assembly","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)  British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes\n\n \n\nAD/HS 748/1 Landing Gear Selector Lever Assembly 12/94\n\nApplicability: Model HS748 aircraft.\n\n \n\nRequirement: Action in accordance with Jetstream Alert Service Bulletin HS748-A-32-95.\n\n \n\nNote: UK CAA AD 007-07-94 refers.\n\n \n\nCompliance: Unless already accomplished, within 250 landings after 10 November 1994, and thereafter at intervals not to exceed 1500 hours time in service.\n\n \n\nBackground: The UK CAA received reports of incidents where the landing gear selector lever cam detached from the shaft causing the landing gear extension/retraction to malfunction.\n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument, as presented, applies specifically to Model HS748 aircraft and requires action per Jetstream Alert Service Bulletin HS748-A-32-95 with the stated compliance windows. The text contains no indication that the AD's scope was amended or expanded from an earlier version; it addresses the specific landing-gear selector-cam failure mode described in the Background and limits the regulatory obligation to the named aircraft model and the service-bulletin action."},"complexity_factors":["Narrow applicability limited to one aircraft model (reduces complexity).","Mandated compliance references an external manufacturer service bulletin (adds dependency on an external technical document and parts availability).","Two different timing metrics: initial requirement stated in landings after a calendar date, recurring interval in hours time-in-service (requires operators to track both landings and flight hours).","Regulatory enforcement context under Part 39 creates administrative compliance and record-keeping obligations.","Cross-reference to a foreign regulator's AD (UK CAA) introduces a coordination/reference element but does not alter the AD’s operative requirement."],"plain_english_summary":"What this instrument does (mechanical change)\n\n- This airworthiness directive (AD) requires operators of British Aerospace (Hawker Siddeley) HS 748 aircraft to carry out the work specified in Jetstream Alert Service Bulletin HS748-A-32-95 (\"the service bulletin\") (Requirement).\n- The AD applies only to Model HS748 aircraft (Applicability).\n- Compliance timing is: perform the initial action within 250 landings after 10 November 1994, and then repeat the specified action at intervals not to exceed 1500 hours time in service (Compliance).\n\nWhy the regulator issued it (stated purpose)\n\n- The stated reason is that the UK CAA received reports that the landing gear selector lever cam had detached from its shaft and caused landing gear extension/retraction malfunctions (Background). The AD cross-references the UK CAA AD (Note).\n\nWho decides and who pays\n\n- The Civil Aviation Safety Authority issues and enforces this AD under the Civil Aviation Regulations Part 39 / Schedule of Airworthiness Directives (header). The AD binds operators/owners of affected HS 748 aircraft to comply with its requirements.\n- The immediate costs of compliance (labour, inspection time, parts, and aircraft downtime) fall on the aircraft owner/operators because the AD mandates the action in the service bulletin (Requirement; Compliance).\n\nHow it changes behaviour and what that implies\n\n- Operators must schedule and carry out the specified inspection/repair/modification from the service bulletin within the specified initial window (250 landings) and at the recurrent interval (≤1500 hours). This changes maintenance planning, creates recurring maintenance cost and aircraft out-of-service time, and requires record-keeping to show compliance (Requirement; Compliance).\n- The AD relies on a manufacturer-issued service bulletin for the detailed technical steps. That reliance means access to that document, availability of parts and qualified technicians, and the ability to follow its procedures determine how quickly and cheaply operators can comply (Requirement).\n\nCosts, incentives, trade-offs and implementation risks (tested against the stated purpose)\n\n- The stated safety benefit is addressing a specific mechanical failure mode (detached selector cam) that can cause landing-gear malfunctions (Background). The AD targets that failure mode by ordering the service bulletin action.\n- Concentration of costs: all direct costs are concentrated on the relatively small set of HS 748 owners/operators because the AD applies only to that model (Applicability). Safety benefits are diffuse (passengers, crew, public) but the compliance cost is concentrated (Compliance).\n- Implementation risks and opportunity costs include: downtime while work is done, potential scarcity of parts or qualified maintenance resources, and administrative burden of scheduling recurrent checks. The AD text does not state alternative compliance options or exemptions, so operators must follow the service bulletin as the required method (Requirement; Compliance).\n- The AD creates a compliance monitoring burden: operators must track landings and hours to meet the initial and recurrent windows (Compliance).\n\nRelevant citations from the instrument\n\n- Applicability: \"Model HS748 aircraft.\" (Applicability)\n- Requirement: \"Action in accordance with Jetstream Alert Service Bulletin HS748-A-32-95.\" (Requirement)\n- Compliance: \"...within 250 landings after 10 November 1994, and thereafter at intervals not to exceed 1500 hours time in service.\" (Compliance)\n- Background: \"...reports of incidents where the landing gear selector lever cam detached from the shaft causing the landing gear extension/retraction to malfunction.\" (Background)\n- Issuing authority: Civil Aviation Regulations Part 39 / Schedule of Airworthiness Directives (header).\n\nBottom line (neutral)\n\n- The AD imposes a mandatory, model-specific maintenance requirement tied to a manufacturer service bulletin, with a short initial deadline and recurring inspection interval. Owners/operators of HS 748 aircraft bear the financial and operational burden of compliance; the regulator requires the work to reduce a specific mechanical failure risk."},"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 specific aircraft type. It has not expanded beyond its original purpose of mandating a particular inspection and repair."},"complexity_factors":["Single, specific mechanical defect addressed","Only one model of aircraft affected (HS 748)","Clear compliance deadline (250 landings from specified date)","Simple recurring requirement (every 1500 hours thereafter)","No defined terms section, no cross-references to other legislation beyond a single service bulletin reference","Total length is approximately 150 words"],"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 **British Aerospace HS 748 series aircraft** to inspect and fix a problem with the **landing gear selector lever assembly** — the control that pilots use to raise and lower the landing gear.\n\n**The safety problem:**\nThe UK aviation regulator received reports that a small mechanical part (the \"cam\") on the landing gear selector lever could detach from its shaft. If this happens, the landing gear might not extend or retract properly — a serious safety risk during takeoff and landing.\n\n**What must be done:**\n- Aircraft operators must follow the repair instructions in **Jetstream Alert Service Bulletin HS748-A-32-95** (a technical notice from the manufacturer)\n- The work must be completed **within 250 landings** after 10 November 1994\n- After that first fix, the landing gear selector must be **re-checked every 1,500 flight hours**\n\n**Who it affects:**\nAnyone operating HS 748 model aircraft in Australia — typically regional airlines, cargo operators, or charter services using these twin-turboprop planes.\n\n**Why it matters:**\nLanding gear failures can be catastrophic. This directive prevents accidents by forcing operators to fix a known mechanical defect before it causes an in-flight emergency."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-748-1-landing-gear-selector-lever-assembly","history":"/api/acts/ad-hs-748-1-landing-gear-selector-lever-assembly/history","analysis":"/api/acts/ad-hs-748-1-landing-gear-selector-lever-assembly/analysis","conflicts":"/api/acts/ad-hs-748-1-landing-gear-selector-lever-assembly/conflicts","importantCases":"/api/acts/ad-hs-748-1-landing-gear-selector-lever-assembly/important-cases","documents":"/api/acts/ad-hs-748-1-landing-gear-selector-lever-assembly/documents"}}