{"id":"F2006B06782","name":"AD/SA-TP/7 - Throttle and CSU Controls","slug":"ad-sa-tp-7-throttle-and-csu-controls","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114628,"registerId":"commonwealth-F2006B06782-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SA-TP/7 - Throttle and CSU Controls","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 (Scottish Aviation) Twin Pioneer Series Aeroplanes\n\n \n\nAD/SA-TP/7 Throttle and CSU Controls NK\n\nApplicability: S/Nos. 501 to 505.\n\n \n\nDocument: Scottish Aviation Mod. No. C344. Compliance: Forthwith.\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\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The source text sets a single, narrowly focused requirement: apply Scottish Aviation Modification No. C344 to Twin Pioneer aeroplanes S/Nos 501–505 immediately. There is no information in the provided text indicating a change from an earlier or different scope; the directive’s scope as stated appears to be its original and operative scope. (Applicability; Document; Compliance.)"},"complexity_factors":["Very narrow applicability (only S/Nos 501–505). (Applicability)","Single required action pointed to an external technical document (Scottish Aviation Mod. No. C344). (Document)","Immediate compliance timing (‘Forthwith’) reduces scheduling flexibility. (Compliance)","Implementation depends on availability and clarity of the external modification document and of qualified maintenance resources. (Document; Compliance)"],"plain_english_summary":"### What this instrument does (mechanically)\n\n- It is an Airworthiness Directive titled “AD/SA-TP/7 Throttle and CSU Controls” issued under the Civil Aviation Regulations 1998, Part 39, and appears in the Civil Aviation Safety Authority schedule of airworthiness directives. (See header.)\n- It applies only to British Aerospace (Scottish Aviation) Twin Pioneer aeroplanes with serial numbers 501 to 505. (Applicability: S/Nos. 501 to 505.)\n- It requires compliance with a specific modification — Scottish Aviation Modification No. C344 — and sets the compliance time as “Forthwith.” (Document: Scottish Aviation Mod. No. C344. Compliance: Forthwith.)\n\n### Who this affects\n\n- The immediate legal obligation falls on the registered owners/operators of Twin Pioneer aeroplanes S/Nos 501–505. They must implement Modification C344 without delay. (Applicability; Document; Compliance.)\n\n### Official purpose and how it operates\n\n- As an airworthiness directive, the measure is presented as addressing a safety/airworthiness matter relating to “Throttle and CSU Controls” (title). The directive operates by mandating a specified modification (Scottish Aviation Mod. No. C344) and making that modification a mandatory compliance action for the named serial-numbered aircraft. (Title; Document; Applicability.)\n\n### Practical effects, costs and incentives\n\n- Who pays: Owners/operators of the five affected aircraft will bear the direct financial cost of carrying out Mod. No. C344 (parts, labour, any required inspections). (Document; Applicability.)\n- Who decides: The regulator (Civil Aviation Safety Authority, via this AD) sets the requirement; owners/operators decide how and when to schedule the work, subject only to the AD’s timing instruction “Forthwith.” (Header; Compliance.)\n- Behaviour changes required: Operators must arrange for the modification to be performed — which will typically require booking maintenance support, obtaining any parts or documentation, and taking the aircraft out of service for the work until it is completed. (Document; Compliance.)\n- Time pressure and flexibility: The command “Forthwith” gives minimal discretion on timing, increasing the immediacy of costs and operational disruption for affected operators. (Compliance: Forthwith.)\n\n### Implementation risk and compliance burden\n\n- Implementation depends on the availability of the modification parts, instructions and suitably qualified maintenance personnel to carry out Mod. No. C344. If any of those are limited, operators may face delays, additional expense, or operational downtime. (Document; Compliance.)\n- Compliance requires interpreting and applying a separate technical document (Scottish Aviation Mod. No. C344). That creates a dependency on the clarity and completeness of that modification document and on the expertise of maintenance providers. (Document.)\n\n### Trade‑offs and opportunity costs\n\n- Operators must allocate funds and maintenance capacity to this mandated modification rather than to other investments or maintenance tasks; they also may lose revenue while the aeroplane is unavailable. (Applicability; Document; Compliance.)\n\n### Concentration of impact and discretion\n\n- The impact is narrowly concentrated (only five serial numbers). The regulator’s decision to make the modification mandatory and immediate concentrates decision power with the issuing authority while shifting implementation costs to the affected operators. (Applicability; Compliance.)\n\n### Net effect summary\n\n- Mechanically, this AD changes nothing except to convert Scottish Aviation Mod. No. C344 into a mandatory, immediate requirement for Twin Pioneer aircraft S/Nos 501–505. Practically, it imposes an immediate compliance cost and operational disruption on the owners/operators of those aircraft and requires those operators to secure the necessary technical resources to implement the specified modification. (Applicability; Document; Compliance.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific technical issue on a limited fleet of vintage aircraft. It remains precisely scoped to its original safety purpose with no evidence of scope creep."},"complexity_factors":["Extremely short document (under 100 words of substantive content)","Only one defined applicability criterion (serial numbers 501–505)","Single compliance requirement with reference to external technical document","No nested conditions, exceptions, or cross-references to other legislation","No interpretive provisions or defined terms section","Straightforward imperative language ('Forthwith') with no temporal calculations or alternative compliance methods"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for a specific type of aircraft: the **British Aerospace (Scottish Aviation) Twin Pioneer** series.\n\n**What it does:**\n- Requires owners/operators of specific Twin Pioneer aircraft (serial numbers 501 to 505) to carry out a modification to the **throttle and Constant Speed Unit (CSU) controls**. The CSU is a device that automatically adjusts aircraft propeller pitch to maintain constant engine speed.\n- The modification must follow **Scottish Aviation Modification No. C344**.\n- **Compliance is immediate** (\"Forthwith\") — meaning it must be done right away, not at the next scheduled maintenance.\n\n**Who it affects:**\n- Owners and operators of the five specific Twin Pioneer aircraft with serial numbers 501–505.\n\n**Why it matters:**\n- This directive addresses a safety issue with the throttle and propeller control systems. These controls are critical for managing engine power and aircraft performance. A defect here could lead to loss of engine control or asymmetric thrust, potentially causing loss of aircraft control."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sa-tp-7-throttle-and-csu-controls","history":"/api/acts/ad-sa-tp-7-throttle-and-csu-controls/history","analysis":"/api/acts/ad-sa-tp-7-throttle-and-csu-controls/analysis","conflicts":"/api/acts/ad-sa-tp-7-throttle-and-csu-controls/conflicts","importantCases":"/api/acts/ad-sa-tp-7-throttle-and-csu-controls/important-cases","documents":"/api/acts/ad-sa-tp-7-throttle-and-csu-controls/documents"}}