{"id":"F2006B07250","name":"AD/T53/20 - Accessory Drive Carrier","slug":"ad-t53-20-accessory-drive-carrier","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49139,"registerId":"commonwealth-F2006B07250-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.","sortOrder":0},{"sectionNumber":"AD/T53/20 Accessory Drive Carrier 8/2000","sectionType":"part","heading":"AD/T53/20 Accessory Drive Carrier 8/2000","content":"# AD/T53/20 Accessory Drive Carrier 8/2000\n\nApplicability: AlliedSignal (formerly Textron Lycoming) T5313B, T5317A, T53-L-703 series and T53 military series engines.\n\nRequirement: Inspect the accessory drive carrier assembly in accordance with one of the following, as applicable, AlliedSignal Aerospace Service Bulletins.","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The supplied text sets out an AD that applies to specified AlliedSignal/T53 engine models and requires inspection of the accessory drive carrier assembly per AlliedSignal Aerospace Service Bulletins. There is no indication in the supplied extract that the AD’s scope has been changed from its original intent. The extract does omit the compliance section and does not list the specific service bulletin identifiers, so the operational details needed to implement the scope (timing and exact bulletin references) are not included here."},"complexity_factors":["Narrow technical scope: applies only to listed AlliedSignal/T53 engine types (Applicability)","Mandatory action is a single technical task — inspection of the accessory drive carrier assembly (Requirement)","Implementation depends on external documents (manufacturer service bulletins), requiring operators to obtain and follow those documents (Requirement)","Key operational detail — the compliance timing — is referenced but not included in the supplied text, creating practical uncertainty (Preamble clauses (a)–(c))","Legal technicality: issued by a CASA delegate under subregulation 39.1(1) of CAR 1998 introduces standard regulatory formality (Preamble)"],"plain_english_summary":"This Airworthiness Directive from a CASA delegate mandates inspection of the accessory‑drive carrier assembly on specified AlliedSignal/Textron Lycoming T53 engine series, using the referenced AlliedSignal service bulletins. Owners/operators must comply, pay inspection and repair costs, and may face downtime. The AD’s legal force is the CASA delegation; obtain the full AD and the cited service bulletins for exact timing and procedures."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This appears to be the original scope of the directive — a targeted safety inspection for a specific engine component. No evidence of scope creep beyond the original safety purpose."},"complexity_factors":["Very short document (approximately 200 words)","Only 1 substantive requirement (inspection of one component)","No defined terms section","Minimal conditional logic — simply refers to 'as applicable' service bulletins","Single cross-reference to manufacturer's technical documents (Service Bulletins)","Straightforward applicability section listing specific engine models"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by the Civil Aviation Safety Authority (CASA) for aircraft.\n\n**What it does:**\n- Requires owners and operators of specific helicopter engines (AlliedSignal T53 series engines, formerly made by Textron Lycoming) to **inspect the accessory drive carrier assembly** — a component that helps power accessories like generators and fuel pumps.\n\n**Who it affects:**\n- Anyone who owns, operates, or maintains aircraft with these specific engine models: T5313B, T5317A, T53-L-703, and T53 military series engines.\n\n**Why it matters:**\n- The directive addresses an **unsafe condition** that could affect flight safety. The inspection is mandatory and must follow specific technical instructions from the manufacturer (AlliedSignal Aerospace Service Bulletins).\n\n**What must be done:**\n- Inspect the accessory drive carrier assembly following the manufacturer's service bulletins.\n- The exact timing for compliance is set out in the \"compliance section\" (not fully shown in this extract)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-t53-20-accessory-drive-carrier","history":"/api/acts/ad-t53-20-accessory-drive-carrier/history","analysis":"/api/acts/ad-t53-20-accessory-drive-carrier/analysis","conflicts":"/api/acts/ad-t53-20-accessory-drive-carrier/conflicts","importantCases":"/api/acts/ad-t53-20-accessory-drive-carrier/important-cases","documents":"/api/acts/ad-t53-20-accessory-drive-carrier/documents"}}