{"id":"F2006B08177","name":"AD/CESSNA 310/49 - Auto Pilot System - Disabling and Modification","slug":"ad-cessna-310-49-auto-pilot-system-disabling-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115375,"registerId":"commonwealth-F2006B08177-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 310/49 - Auto Pilot System - Disabling and Modification","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nCessna 310 Series Aeroplanes\n\nAD/CESSNA 310/49 Auto Pilot System \\- Disabling\n\nand Modification\n\n  \n6/78\n\nApplicability: Models 310R, T310R, S/Nos. 310R0501 to 310R1302, 310R1304 to 310R1315, 310R1317 and 310R1318 incorporating ARC Model 400B auto pilot installations.\n\nRequirement: 1. On aircraft not modified in accordance with Cessna SL No. AV78 -6 dated 31 March 1978 or later revision, disable the model 400B auto pilot by pulling and banding AUTO PILOT (COMP) and ACTUATOR (ACT) circuit breakers.\n\n    2. Install a placard in plain view of the pilot indicating “AUTO PILOT INOPERATIVE”.\n\n    3. Upon accomplishment of the electrical auto pilot actuator modification set out in Cessna SL No. AV78-6, the auto pilot may be returned to service and the “AUTO PILOT INOPERATIVE” placard removed.\n\nCompliance: Paras. 1 and 2 \\- Before further flight.\n\nPara. 3 \\- Before further flight using auto pilot.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope. It addresses a specific safety defect in specific aircraft models with a specific autopilot system. There is no evidence of scope creep; the directive remains tightly focused on the autopilot grounding and modification requirements as originally intended."},"complexity_factors":["Very short document (approximately 150 words)","Only 3 operative requirements with clear sequential numbering","Single applicability criterion (specific aircraft models and serial numbers)","No defined terms section or interpretation provisions","No cross-references to other legislation (only references to Cessna Service Letter AV78-6, which is external technical documentation)","Simple conditional logic (if modified per SL AV78-6, placard can be removed)","Clear, immediate compliance deadlines ('Before further flight')"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for specific Cessna 310 aircraft models.\n\n**What it does:**\n- **Grounds the autopilot system** on certain Cessna 310R and T310R planes (specific serial numbers) that have the ARC Model 400B autopilot installed.\n- **Requires immediate action:** Before the aircraft can fly again, operators must physically disable the autopilot by pulling and securing two specific circuit breakers, and install a visible warning placard saying \"AUTO PILOT INOPERATIVE\".\n- **Provides a fix:** Once the aircraft is modified according to Cessna Service Letter AV78-6 (an electrical actuator upgrade), the autopilot can be used again and the warning sign removed.\n\n**Who it affects:**\n- Owners and operators of specific Cessna 310R and T310R aircraft (serial numbers 310R0501 to 310R1302, 310R1304 to 310R1315, 310R1317 and 310R1318) with the ARC 400B autopilot.\n\n**Why it matters:**\nThis directive addresses a serious safety defect in the autopilot system. The mandatory grounding prevents potential accidents caused by autopilot malfunction until a permanent engineering fix is applied. It's a \"fix it before you fly\" order—no exceptions, no delays."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive applies to the specified Cessna 310 serial numbers with ARC Model 400B autopilot installations and requires disabling the autopilot until the electrical actuator modification in Cessna SL No. AV78-6 is completed (Applicability; Requirement 1–3). The text does not indicate any expansion or narrowing of scope from an earlier or original statement within the instrument itself, so there is no change of scope recorded in the provided text."},"complexity_factors":["Narrow applicability tied to specific airframe models and serial numbers (Applicability).","Simple, prescriptive mechanical actions (pull and band two circuit breakers; install placard) reduce procedural complexity (Requirement 1–2).","Reference to an external technical document (Cessna SL No. AV78-6) for the approved corrective modification introduces dependency on another source and potential variation by revision (Requirement 3).","Immediate compliance timing (\"Before further flight\") creates operational urgency and scheduling complexity for operators (Compliance: Paras. 1–2).","No alternative mitigation or approval pathway is provided in the text, so compliance options are binary (disable/modify), which simplifies legal interpretation but concentrates practical burden on operators (Requirement 1–3)."],"plain_english_summary":"This directive requires certain Cessna 310R/T310R airframes (listed serial numbers) with ARC Model 400B autopilots to have the autopilot electrically disabled—pull and band the AUTO PILOT (COMP) and ACTUATOR (ACT) breakers and fit a visible “AUTO PILOT INOPERATIVE” placard—until the actuator modification in Cessna Service Letter AV78‑6 is completed. It affects owners/operators and pilots, who must implement the disablement before flight or pay for the service‑letter modification to restore autopilot use."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-310-49-auto-pilot-system-disabling-and-modification","history":"/api/acts/ad-cessna-310-49-auto-pilot-system-disabling-and-modification/history","analysis":"/api/acts/ad-cessna-310-49-auto-pilot-system-disabling-and-modification/analysis","conflicts":"/api/acts/ad-cessna-310-49-auto-pilot-system-disabling-and-modification/conflicts","importantCases":"/api/acts/ad-cessna-310-49-auto-pilot-system-disabling-and-modification/important-cases","documents":"/api/acts/ad-cessna-310-49-auto-pilot-system-disabling-and-modification/documents"}}