{"id":"F2006B08263","name":"AD/CESSNA 340/17 - Auto Pilot System - Disabling - Modification","slug":"ad-cessna-340-17-auto-pilot-system-disabling-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115570,"registerId":"commonwealth-F2006B08263-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 340/17 - Auto Pilot System - Disabling - 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 340 Series Aeroplanes\n\nAD/CESSNA 340/17 Auto Pilot System \\- Disabling \\- Modification 6/78\n\nApplicability: Model 340A S/Nos. 340A0001 to 340A0458, 340A0460 to 340A0466, 340A0468 and 340A0470 to 340A0483; 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 autopilot by pulling and banding AUTO PILOT COMPUTER (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 autopilot.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive, as presented, sets a narrow, specific scope: it applies only to the listed Cessna 340A serial numbers with ARC Model 400B autopilot installations and prescribes disablement and a specific modification pathway (Applicability; Requirement 1–3). The provided text does not indicate any expansion or contraction of that scope beyond those explicit provisions."},"complexity_factors":["Narrow applicability limited to specific Cessna 340A serial numbers and ARC Model 400B installations (Applicability).","Simple, prescriptive technical actions (pull and band two circuit breakers; install placard) that are easy to describe but require physical access and maintenance action (Requirement 1–2).","Dependency on an external technical document (Cessna SL No. AV78-6) to restore full functionality, creating a coordination requirement with manufacturer guidance (Requirement 3).","Immediate compliance timing (must be done before further flight) increases operational urgency (Compliance: Paras. 1 and 2).","No alternative compliance paths or waiver language in the provided text, limiting regulatory flexibility and increasing binary compliance choices (Requirement 1–3)."],"plain_english_summary":"This directive applies to specified Cessna 340A serial numbers with an ARC Model 400B autopilot and requires operators to disable that autopilot (pull and band the AUTO PILOT COMPUTER and ACTUATOR circuit breakers) and fit a visible “AUTO PILOT INOPERATIVE” placard before the next flight unless the aircraft has already been modified per Cessna Service Letter AV78‑6. It affects owners/operators, maintenance organisations, and pilots because autopilot use is barred until the specified modification is completed."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with a narrow, targeted scope addressing a specific safety defect in a specific aircraft model. The scope remains tightly focused on the autopilot safety issue as originally intended."},"complexity_factors":["Single, specific aircraft model and limited serial number range","Only 3 straightforward compliance requirements","No defined terms section or complex interpretation provisions","Simple conditional logic (if modified do X, if not modified do Y)","Clear, immediate compliance deadlines","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for specific Cessna 340A aircraft.\n\n**What it does:**\n- **Grounds the autopilot** on certain Cessna 340A planes until a safety fix is applied\n- Requires pilots to physically disable the autopilot system by pulling specific circuit breakers\n- Mandates a visible warning placard stating \"AUTO PILOT INOPERATIVE\"\n- Allows the autopilot to be reactivated only after a specific electrical modification is completed\n\n**Who it affects:**\n- Owners and operators of Cessna 340A aircraft with serial numbers 340A0001 to 340A0458, 340A0460 to 340A0466, 340A0468, and 340A0470 to 340A0483\n- Specifically targets planes with ARC Model 400B autopilot systems that haven't been modified per Cessna Service Letter AV78-6\n\n**Why it matters:**\nThis directive addresses a critical safety defect in the autopilot system. The aircraft cannot legally fly with the autopilot engaged until the modification is completed. The requirements are immediate — operators must comply before the next flight."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-340-17-auto-pilot-system-disabling-modification","history":"/api/acts/ad-cessna-340-17-auto-pilot-system-disabling-modification/history","analysis":"/api/acts/ad-cessna-340-17-auto-pilot-system-disabling-modification/analysis","conflicts":"/api/acts/ad-cessna-340-17-auto-pilot-system-disabling-modification/conflicts","importantCases":"/api/acts/ad-cessna-340-17-auto-pilot-system-disabling-modification/important-cases","documents":"/api/acts/ad-cessna-340-17-auto-pilot-system-disabling-modification/documents"}}