{"id":"F2006B08359","name":"AD/CESSNA 400/76 - King Automatic Pilot Roll Axis Slip Clutch Setting","slug":"ad-cessna-400-76-king-automatic-pilot-roll-axis-slip-clutch-setting","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115766,"registerId":"commonwealth-F2006B08359-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 400/76 - King Automatic Pilot Roll Axis Slip Clutch Setting","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 400 Series Aeroplanes\n\nAD/CESSNA 400/76 King Automatic Pilot Roll Axis\n\nSlip Clutch Setting\n\n  \n12/80\n\nApplicability: Model 421C with S/Nos. 421C0401 and up which have King Radio Model KFC-200 Flight Control System installed under Supplemental Type Certificate SA1246CE.\n\nDocument: 1. FAA AD 80-20-06, Amdt. 39-3937. Or\n\n2. King Radio Installation Bulletin No. 167. Compliance: Within 25 hours time in service after 27 October 1980.\n\nBackground: Cessna Aircraft made an aileron tab actuator change in 421C aeroplanes effective with S/No. 421C0401. This change has made it necessary to decrease the roll axis clutch torque in the KFC-200 Flight Control System to prevent the aircraft from exceeding 60 degrees bank angle in the event of a hardover roll axis malfunction.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive is corrective and narrowly focused: it addresses a particular hardware change (aileron tab actuator introduced from S/N 421C0401) by mandating a specific adjustment to an installed autopilot. It does not broaden the regulated population beyond the identified serial numbers and STC installation, nor does it add ongoing new categories of regulatory control—it imposes a one-off maintenance action within a short compliance window. (Applicability; Background; Compliance)"},"complexity_factors":["Narrow applicability limited to Model 421C S/N 421C0401 and up with a specific STC-installed autopilot (low population of affected aircraft). (Applicability)","Single technical action required (reduce roll-axis clutch torque) rather than multiple conditional steps. (Background)","Clear, short compliance deadline (25 hours TIS after 27 October 1980) increases urgency but not legal complexity. (Compliance)","Dependence on external technical documents (FAA AD and King Radio Installation Bulletin) requires access to and reliance on those texts for the exact procedure. (Document)","Technical task requires qualified maintenance personnel and equipment, adding operational (not regulatory) complexity."],"plain_english_summary":"This directive requires lowering the roll‑axis slip‑clutch torque on King KFC‑200 autopilots installed on Cessna 421C (S/N 421C0401 and up, STC SA1246CE) so the autopilot will apply less roll torque during a hardover. Owners/operators must have the adjustment done per FAA AD 80‑20‑06 or King Bulletin No. 167 within 25 hours TIS after 27 Oct 1980, at their expense.\n\nThe change limits maximum bank in a roll‑axis malfunction (preventing >60° bank)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical incompatibility between a design change and an installed autopilot system. It has not expanded beyond its original technical safety purpose."},"complexity_factors":["Single, specific technical requirement (adjust clutch torque setting)","Narrow applicability (one aircraft model, specific serial number range, specific autopilot system)","No defined terms section or complex interpretive provisions","Simple compliance pathway (two alternative reference documents)","Clear deadline (25 hours time in service after specified date)","No nested exceptions, conditional logic, or cross-references to other legislation"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific Cessna 421C aircraft to adjust the automatic pilot (autopilot) system.\n\n**What it does:**\n- Targets Cessna 421C aircraft (serial numbers 421C0401 and higher) that have a King KFC-200 autopilot system installed\n- Requires a mechanical adjustment to the \"slip clutch\" in the autopilot's roll (banking/turning) axis\n- The clutch torque setting must be reduced to a lower level\n\n**Why it matters:**\nCessna changed the aileron tab actuator design in these aircraft. Without this adjustment, if the autopilot malfunctioned and commanded a hard turn (\"hardover\"), the aircraft could bank beyond 60 degrees — a dangerous situation that could lead to loss of control.\n\n**Who must comply:**\n- Owners/operators of affected Cessna 421C aircraft\n- Must complete the fix within 25 flight hours after 27 October 1980\n\n**How to comply:**\nFollow either FAA Airworthiness Directive 80-20-06 or King Radio Installation Bulletin No. 167"}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-400-76-king-automatic-pilot-roll-axis-slip-clutch-setting","history":"/api/acts/ad-cessna-400-76-king-automatic-pilot-roll-axis-slip-clutch-setting/history","analysis":"/api/acts/ad-cessna-400-76-king-automatic-pilot-roll-axis-slip-clutch-setting/analysis","conflicts":"/api/acts/ad-cessna-400-76-king-automatic-pilot-roll-axis-slip-clutch-setting/conflicts","importantCases":"/api/acts/ad-cessna-400-76-king-automatic-pilot-roll-axis-slip-clutch-setting/important-cases","documents":"/api/acts/ad-cessna-400-76-king-automatic-pilot-roll-axis-slip-clutch-setting/documents"}}