{"id":"F2006B04312","name":"AD/BEECH 99/2 - Stabiliser Actuator - Replacement","slug":"ad-beech-99-2-stabiliser-actuator-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44127,"registerId":"commonwealth-F2006B04312-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEECH 99/2 - Stabiliser Actuator - Replacement","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)  Beechcraft 99 Series Aeroplanes\n\n \n\nAD/BEECH 99/2 Stabiliser Actuator - Replacement 2/94\n\nApplicability: Serial No’s U-2 to U-64 except U-36.\n\n \n\nRequirement: Action in accordance with the technical requirements of 0172-132. Compliance: Effective 3 February 1994.\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":true,"description":"The AD’s title includes the word 'Replacement', indicating it replaces or supersedes an earlier instruction. The supplied text sets a replacement requirement for stabiliser actuators on the specific serial-numbered Beechcraft 99 aircraft and fixes an effective compliance date (Applicability; Requirement; Compliance). No prior or earlier instrument text is provided here, so the exact differences from any predecessor cannot be determined from the supplied document alone."},"complexity_factors":["Very narrow technical scope limited to specific serial numbers (Applicability).","Mandates action by reference to an external technical document (0172-132), requiring access to and interpretation of that document (Requirement).","Immediate compliance date creates scheduling and potential operational-disruption complexity (Compliance).","The AD text supplied lacks explanatory detail on enforcement, acceptable alternatives, or record-keeping formats, increasing implementation ambiguity.","Little regulatory discretion within the AD itself (it prescribes a single required action), but practical discretion sits with maintenance providers and operators on timing and execution."],"plain_english_summary":"### What this instrument does (mechanically)\nThis Airworthiness Directive (AD) orders replacement of the stabiliser actuator on certain Beechcraft 99 series aeroplanes. It applies to aeroplanes with serial numbers U-2 through U-64 except U-36 (Applicability). The replacement work must be carried out in accordance with the technical instructions identified as 0172-132 (Requirement). The directive was required to be complied with from 3 February 1994 (Compliance).\n\n### Who this affects\n- Aircraft owners and operators of Beechcraft 99 series aeroplanes that match the listed serial numbers (Applicability).  \n- Maintenance organisations and technicians who perform or certify the replacement work (Requirement).  \n- Any organisation that keeps airworthiness records and demonstrates regulatory compliance to the Civil Aviation Safety Authority or its authorised delegates (Compliance).\n\n### Why it matters (as stated and as implied)\nThe text of the AD itself sets a mandatory technical action (replacement of the stabiliser actuator per 0172-132) and a clear applicability and compliance date. The document does not include an explanatory narrative or background within the supplied text; it does not state the specific operational problem prompting the replacement. Because it is an airworthiness directive, the mandatory mechanism is the central effect: specified aircraft must have the part replaced according to the referenced technical procedure (Requirement).\n\n### Who pays, who decides, and the immediate effects on behaviour\n- Who pays: Aircraft owners/operators will bear the direct costs of parts, labour and any aircraft downtime needed to perform the replacement (Requirement; Applicability).  \n- Who decides: The regulator has issued the mandatory requirement; compliance method and timing are defined by the technical instructions 0172-132 that the AD references. Maintenance providers implement the work and certify compliance (Requirement).  \n- Behaviour changes: Operators must schedule and complete the replacement by following 0172-132. Operators may ground affected aircraft until the action is complete, or impose operational restrictions until compliance is proven (Compliance).\n\n### Costs, incentives, trade-offs and implementation risks (source-grounded)\n- Cost concentration and incidence: Costs are concentrated on the owners/operators of the listed serial-number aircraft (Applicability). There is likely short-run demand for replacement parts and maintenance labour, which benefits maintenance providers and parts suppliers.  \n- Compliance burden and paperwork: The AD requires following an external technical document (0172-132). That creates an administrative step: obtain the technical instructions, schedule the work, and document compliance for the regulator (Requirement). The AD text supplied does not include enforcement or record-keeping detail; those processes will rely on standard regulatory practice and therefore create implementation tasks for operators.  \n- Discretion and room for variation: The directive prescribes the action by reference to a specific technical document, which constrains discretion about how the replacement should be performed. The AD text does not offer alternative methods or deviations; therefore discretion for operators is limited to scheduling and contractor selection (Requirement).  \n- Opportunity costs and operational disruption: Aircraft downtime to complete the replacement is an operational cost and could reduce service availability for operators during compliance (Compliance).  \n- Information completeness and reliance on external document: Because the AD refers to 0172-132 for technical detail, parties must obtain and follow that document to understand exact parts, procedures and certification steps. The AD’s effectiveness therefore depends on access to and clarity of 0172-132 (Requirement).\n\n### Implementation checkpoints (source references)\n- Confirm whether your aircraft serial number is within U-2 to U-64 excluding U-36 (Applicability).  \n- Obtain technical requirements document 0172-132 and arrange replacement work per that document (Requirement).  \n- Complete replacement and satisfy any required certification/records by or following the compliance date specified (Effective 3 February 1994) (Compliance)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-limited safety directive targeting a specific mechanical defect in a narrow aircraft fleet. It has not expanded beyond its original purpose of mandating a single component replacement."},"complexity_factors":["Extremely short document (under 150 words)","Only one substantive requirement (replacement of a single component)","Single applicability criterion (serial number range with one exception)","No defined terms section","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Single compliance date with no conditional triggers or phased implementation","References external technical document (0172-132) but does not reproduce its contents"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific **Beechcraft 99 series aeroplanes** to replace a faulty **stabiliser actuator** (a mechanical device that controls the horizontal tail surface, crucial for keeping the aircraft level during flight).\n\n**Who it affects:**\n- Owners and operators of Beechcraft 99 aircraft with serial numbers U-2 through U-64, **except** serial number U-36.\n\n**What must be done:**\n- Replace the stabiliser actuator following the technical instructions in document **0172-132** (likely a manufacturer service bulletin or engineering order).\n\n**When:**\n- Compliance was required from **3 February 1994**.\n\n**Why it matters:**\nStabiliser actuators are critical flight control components. A malfunction could cause loss of pitch control — the ability to raise or lower the aircraft's nose — potentially leading to catastrophic accidents. This AD ensures unsafe components are removed from service before they fail."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-99-2-stabiliser-actuator-replacement","history":"/api/acts/ad-beech-99-2-stabiliser-actuator-replacement/history","analysis":"/api/acts/ad-beech-99-2-stabiliser-actuator-replacement/analysis","conflicts":"/api/acts/ad-beech-99-2-stabiliser-actuator-replacement/conflicts","importantCases":"/api/acts/ad-beech-99-2-stabiliser-actuator-replacement/important-cases","documents":"/api/acts/ad-beech-99-2-stabiliser-actuator-replacement/documents"}}