{"id":"F2006B11074","name":"AD/LA-4/24 - Automatic Flight Control System","slug":"ad-la-4-24-automatic-flight-control-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56710,"registerId":"commonwealth-F2006B11074-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/LA-4/24 - Automatic Flight Control System","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)  \nConsolidated Aeronautics, Colonial and LA-4 Series Aeroplanes\n\nAD/LA-4/24 Automatic Flight Control System 1/95 DM\n\nApplicability: All Lake Model 250 aircraft that are equipped with a Bendix/King KFC 150 Automatic Flight Control System.\n\nRequirement: 1. Deactivate the automatic flight control by pulling the circuit breakers marked 'A/P' and 'TRIM' and attach a collar or tie-wrap to the circuit breakers to prevent their resetting.\n\n2. Fabricate a placard with the words \\`USE MANUAL TRIM ONLY’ and install this placard on the instrument panel within the pilot’s clear view.\n\nNote: FAA AD 94-22-02 Amdt 39-9051 refers.\n\nCompliance: Within ten hours time in service from 9 November 1994.\n\nBackground: The FAA has received a report where the Bendix/King KFC 150 system malfunctioned because the elevator trim spring lever failed to return to neutral following automatic flight control system autotrim operation resulting in the aircraft deviating from its flight path. Compliance with this Directive is designed to prevent flight path deviations caused by failure of the elevator autotrim to disengage.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical fault in a specific aircraft model. It has not expanded beyond its original purpose of grounding/disabling a faulty autopilot system pending proper repair."},"complexity_factors":["Very short document (under 300 words)","Only 2 operative requirements with clear, sequential steps","Single defined term: 'Applicability' clearly specifies affected aircraft by model and equipment","No cross-references to other legislation (only a non-binding reference to related FAA directive)","Simple conditional logic: if aircraft matches description, requirements apply","No exceptions, exemptions, or nested conditions"],"plain_english_summary":"This CASA Airworthiness Directive affects Lake Model 250 seaplanes fitted with the Bendix/King KFC‑150 autopilot. It requires operators to disable the autopilot and mark the panel to use manual trim, within 10 flight hours of 9 Nov 1994, because a trim‑spring fault can leave the elevator trimmed away from neutral and cause sudden loss of control. It mirrors prior FAA action."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive's scope is confined to Lake Model 250 aircraft equipped with the specified KFC 150 unit and prescribes disabling that system plus a placard; nothing in the instrument text indicates an expansion or narrowing beyond that stated applicability and the two specified requirements (Applicability; Requirement 1–2)."},"complexity_factors":["Narrow applicability: only Lake Model 250 aircraft with Bendix/King KFC 150 are affected (Applicability).","Immediate, short compliance window: actions required within ten hours time in service from 9 November 1994 (Compliance).","Simple, low-technical actions: pull two labelled circuit breakers, secure them, and install a placard (Requirement 1–2).","Operational impact: disables automatic flight control/autotrim and forces manual trim use for pilots (Requirement 1; Background).","Cross-reference to FAA directive shows reliance on foreign-sourced failure report for the safety rationale (Note; Background)."],"plain_english_summary":"**What it does:** This Airworthiness Directive requires owners/operators of Lake Model 250 aeroplanes fitted with a Bendix/King KFC 150 automatic flight control system to disable the autopilot and trim (pull the 'A/P' and 'TRIM' circuit breakers and secure them) and to install a visible placard reading \"USE MANUAL TRIM ONLY.\"  \n\n**Why it matters:** The measure responds to an FAA report that the autotrim failed to return to neutral and caused a flight-path deviation; compliance is required within ten hours to prevent similar incidents (Applicability; Requirement 1–2; Compliance; Background)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-la-4-24-automatic-flight-control-system","history":"/api/acts/ad-la-4-24-automatic-flight-control-system/history","analysis":"/api/acts/ad-la-4-24-automatic-flight-control-system/analysis","conflicts":"/api/acts/ad-la-4-24-automatic-flight-control-system/conflicts","importantCases":"/api/acts/ad-la-4-24-automatic-flight-control-system/important-cases","documents":"/api/acts/ad-la-4-24-automatic-flight-control-system/documents"}}