{"id":"F2006B10820","name":"AD/INST/19 - ARC PA 500A Actuators - Cessna Auto Pilot, AFCS & Yaw Damper - Inspection and Modification","slug":"ad-inst-19-arc-pa-500a-actuators-cessna-auto-pilot-afcs-yaw-damper-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56298,"registerId":"commonwealth-F2006B10820-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/INST/19 - ARC PA 500A Actuators - Cessna Auto Pilot, AFCS & Yaw Damper - Inspection and Modification","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 - 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Instruments and Automatic Pilots\n\n \n\n# AD/INST/19  ARC PA 500A Actuators - Cessna Auto Pilot, AFCS & Yaw Damper - Inspection and Modification\n\nApplicability: ARC PA500A actuators S/Nos. 6265 and below. Document:  1. ARC Field Engineering SB No. 181; or\n\n2. Cessna Avionics SL AV75-10; or 3. FAA AD 76-04-03.\n\n# 6/76\n\nCompliance: Inspection - within 100 hours time in service after 30 July 1976 and thereafter at intervals not exceeding 100 hours time in service until actuator is modified.\n\nModification -Before 30 April 1977.\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":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted Airworthiness Directive addressing a specific safety defect in a specific aircraft component. It has not expanded beyond its original scope — it remains focused solely on the ARC PA500A actuator inspection and modification requirements as originally intended."},"complexity_factors":["Very short document (approximately 150 words)","Only 3 defined applicability criteria (specific actuator model, serial number range, and reference documents)","Simple binary compliance structure (inspection + modification)","No nested exceptions or conditional logic","Clear deadlines and intervals specified in plain calendar/flight hours","Only 3 reference documents cited","Single purpose: address one specific mechanical defect in one component"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It applies to specific aircraft equipment: **ARC PA500A actuators** (mechanical devices that move control surfaces) with serial numbers 6265 and below, used in Cessna aircraft for autopilot systems, automatic flight control systems (AFCS), and yaw dampers (which help keep the plane stable).\n\n**What it requires:**\n- **Inspections**: Aircraft operators must inspect these actuators every 100 hours of flight time, starting from 30 July 1976, and keep doing so until the part is permanently modified.\n- **Modification**: The actuator must be permanently modified before 30 April 1977.\n\n**Why it matters:**\nThis directive addresses a safety defect in these specific actuators. Without inspection and modification, the equipment could fail during flight, potentially compromising the autopilot or flight stability systems. This is a **time-critical safety mandate** — operators who don't comply risk certificate cancellation or grounding of their aircraft.\n\n**Who it affects:**\nOwners and operators of Cessna aircraft equipped with these specific ARC PA500A actuators, particularly those in commercial or private aviation using older Cessna models with these autopilot systems."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The supplied text sets out a single, narrow scope: inspections and a mandatory modification for ARC PA500A actuators S/N 6265 and below, with specified inspection intervals and a modification deadline. The excerpt contains no indications that the scope has been expanded or altered from an earlier or different intent; no amendments or alterations to applicability or compliance requirements are shown in the provided material."},"complexity_factors":["Narrow, serial-number-based applicability (ARC PA500A S/N 6265 and below) reduces scope complexity","Strict, short inspection interval (every 100 hours TIS) until modification increases operational/administrative burden","Fixed modification deadline adds urgency and a one-time compliance action","References to three external technical documents (ARC Field Engineering SB No.181; Cessna Avionics SL AV75-10; FAA AD 76-04-03) require operators to locate and follow external material","No text in the excerpt about exemptions, alternative compliance, or enforcement discretion creates possible ambiguity for practitioners seeking relief or clarification"],"plain_english_summary":"This Airworthiness Directive applies to ARC PA500A actuators with serial numbers 6265 and below, requiring inspections within 100 hours TIS after 30 July 1976 and every 100 hours thereafter until the actuator is modified, with modification mandated by 30 April 1977. It directs compliance via one of three referenced technical documents, affects owners/operators who bear inspection/modification costs, and is issued/enforced by the Civil Aviation Safety Authority to manage the equipment risk."}},"importantCases":[],"_links":{"self":"/api/acts/ad-inst-19-arc-pa-500a-actuators-cessna-auto-pilot-afcs-yaw-damper-inspection-and-modification","history":"/api/acts/ad-inst-19-arc-pa-500a-actuators-cessna-auto-pilot-afcs-yaw-damper-inspection-and-modification/history","analysis":"/api/acts/ad-inst-19-arc-pa-500a-actuators-cessna-auto-pilot-afcs-yaw-damper-inspection-and-modification/analysis","conflicts":"/api/acts/ad-inst-19-arc-pa-500a-actuators-cessna-auto-pilot-afcs-yaw-damper-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-inst-19-arc-pa-500a-actuators-cessna-auto-pilot-afcs-yaw-damper-inspection-and-modification/important-cases","documents":"/api/acts/ad-inst-19-arc-pa-500a-actuators-cessna-auto-pilot-afcs-yaw-damper-inspection-and-modification/documents"}}