{"id":"F2006B07286","name":"AD/TB10/19 - Autopilot Master Switch","slug":"ad-tb10-19-autopilot-master-switch","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49242,"registerId":"commonwealth-F2006B07286-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TB10/19 - Autopilot Master Switch","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)  Aerospatiale (Socata) TB9 and TB10 (Tobago) Series Aeroplanes\n\n \n\nAD/TB10/19 Autopilot Master Switch 2/92\n\nApplicability: All model TB10 aircraft series with serial numbers 275 through 1222 fitted with one of the following options:\n\n \n\n668, G668, 669, G669, 670 or G670.\n\n \n\nRequirement: Action in accordance with Aerospatiale SOCATA Service Bulletin No 60.\n\nNote: DGAC AD 91-145A refers.\n\nCompliance: Prior to the next Maintenance Release after 28 February 1992. Background:  To reduce the risk of a short circuit at the “A/P Master” switch.\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 AD as published prescribes a targeted corrective action for a defined set of TB10 aircraft (Applicability) and requires operators to follow Aerospatiale SOCATA Service Bulletin No 60 (Requirement) by a specified Maintenance Release deadline (Compliance) to reduce the risk of a short circuit at the autopilot master switch (Background). Nothing in the text indicates an expansion or narrowing of that scope from an earlier or different stated intent."},"complexity_factors":["Narrow applicability: specific model (TB10) and serial-number range (275–1222) with listed option codes","Single mandated action: compliance with a single manufacturer Service Bulletin (No 60)","Deadline tied to operational event (next Maintenance Release after a given date) rather than complex phased schedule","External technical detail outsourced to the Service Bulletin (requires access to and interpretation of another document)","Regulatory cross-reference to another authority's AD (DGAC AD 91-145A) which may require coordination"],"plain_english_summary":"# What this directive does\n\nThis is an Airworthiness Directive (AD/TB10/19) that requires specific maintenance action on certain Aerospatiale (Socata) TB10 (Tobago) aeroplanes. Mechanically, it orders operators to carry out the work described in Aerospatiale SOCATA Service Bulletin No 60 on affected aeroplanes (Requirement). The AD is limited to TB10 airframes with serial numbers 275 through 1222 that are fitted with option 668, G668, 669, G669, 670 or G670 (Applicability). Compliance must be achieved before the next Maintenance Release after 28 February 1992 (Compliance). The stated reason for the AD is to reduce the risk of a short circuit at the autopilot master (“A/P Master”) switch (Background).\n\n# Who it affects and who pays\n\n- Owners/operators of TB10 aircraft in the serial-number and options range identified are directly affected (Applicability). They are the parties required to arrange and pay for the inspection/modification/work set out in Service Bulletin No 60 (Requirement).\n\n# How it works in practice\n\n- The AD does not set out step-by-step technical instructions itself; it mandates compliance with Aerospatiale SOCATA Service Bulletin No 60, so the specific technical actions, parts and procedures are those described in that Service Bulletin (Requirement).\n- Operators must schedule the required work to be completed no later than the next Maintenance Release after 28 February 1992 (Compliance). That sets a deadline linked to an existing maintenance event rather than a fixed calendar date.\n\n# Why the regulator issued it (stated purpose) and how that trades off against costs\n\n- The AD states its purpose as reducing the risk of an electrical short at the autopilot master switch (Background). That creates an incentive for operators to eliminate a potential electrical-hazard failure mode.\n- The costs imposed are the time, labour and any parts required to carry out the Service Bulletin work. Those costs fall on affected aircraft owners/operators (Applicability, Requirement). The opportunity cost is the maintenance capacity and money diverted from other work to complete this mandated action by the specified Maintenance Release.\n\n# Compliance burden, discretion and implementation risk\n\n- Compliance burden: Operators must obtain the Service Bulletin, arrange qualified personnel and complete the work by the specified maintenance event (Requirement, Compliance). The AD itself gives no technical discretion; it points to the manufacturer’s Service Bulletin for the required technical solution (Requirement).\n- Implementation risk: If the Service Bulletin is ambiguous, if approved parts or skilled labour are unavailable, or if scheduling pushes the work close to the deadline, there is a risk of non-compliance or incomplete mitigation. The AD cross-references DGAC AD 91-145A, indicating related regulatory action by another authority (Note).\n\n# Concentration of benefits and costs\n\n- Costs are concentrated on the operators/owners of the specified TB10 aircraft (Applicability). The stated safety benefit (reduced short-circuit risk) accrues to those same operators and to aircraft users and third parties exposed to the aircraft’s operations (Background).\n\n# Net operational effect\n\n- The AD obliges a one-time technical action tied to a Service Bulletin and a near-term maintenance deadline. It alters private operational planning by requiring scheduling of the Service Bulletin work by the next Maintenance Release after 28 February 1992 and imposes direct maintenance expense on the affected owners/operators (Requirement, Compliance).\n\n(References in parentheses refer to the relevant lines in the AD text: Applicability, Requirement, Compliance, Background, Note.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific technical defect in a limited aircraft population. It has not expanded beyond its original purpose of mandating a particular modification to prevent autopilot switch short circuits."},"complexity_factors":["Single, specific requirement referencing an external technical document (Service Bulletin No. 60)","Narrow applicability limited to specific aircraft serial numbers and equipment options","No defined terms section or complex conditional logic","Straightforward compliance deadline tied to a standard aviation maintenance event","Minimal cross-referencing (only one related French aviation directive mentioned in a note)"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It applies to specific **Socata TB10 Tobago aircraft** (serial numbers 275–1222) that have certain autopilot equipment installed.\n\n**What it requires:**\n- Owners or operators of affected aircraft must carry out a specific repair or modification outlined in **Aerospatiale SOCATA Service Bulletin No. 60**.\n- This involves fixing the **autopilot master switch** to prevent electrical short circuits.\n\n**Who must comply:**\n- Anyone operating or maintaining the specified TB10 aircraft with the listed equipment options (668, G668, 669, G669, 670, or G670).\n\n**When it had to be done:**\n- Before the aircraft's next **Maintenance Release** (a formal certificate allowing the aircraft to fly) after 28 February 1992.\n\n**Why it matters:**\n- Short circuits in the autopilot master switch could cause system failures or safety hazards during flight. This directive ensures a known defect is fixed before the aircraft returns to service."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tb10-19-autopilot-master-switch","history":"/api/acts/ad-tb10-19-autopilot-master-switch/history","analysis":"/api/acts/ad-tb10-19-autopilot-master-switch/analysis","conflicts":"/api/acts/ad-tb10-19-autopilot-master-switch/conflicts","importantCases":"/api/acts/ad-tb10-19-autopilot-master-switch/important-cases","documents":"/api/acts/ad-tb10-19-autopilot-master-switch/documents"}}