{"id":"F2006B10846","name":"AD/INST/42 - KSA 470 Autopilot Servo Actuator","slug":"ad-inst-42-ksa-470-autopilot-servo-actuator","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56335,"registerId":"commonwealth-F2006B10846-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/INST/42 - KSA 470 Autopilot Servo Actuator","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png) \nInstruments and Automatic Pilots\n\nAD/INST/42 KSA 470 Autopilot Servo Actuator 7/98\n\nApplicability: Allied Signal Bendix/King Model KSA-470 autopilot servo actuators, part numbers 065-0076-10 through 065-0076-15, serial numbers 0001 through 3081 inclusive.\n\nNote: The actuators are known to be fitted to, but not limited to the aircraft listed below:\n\n```html\n

Aircraft Flight

Part Number

Location

Director/Auto pilot System

Raytheon (Beech) 400 Series

KFC 400

065-0076-11

Yaw Axis

065-0076-15

Roll Axis

Raytheon (Beech) 200 Series

KFC 400

065-0076-11

Yaw Axis

Raytheon (Beech) 300 Series

KFC 400

065-0076-15

Yaw Axis

Dassault Falcon 20

KFC 400

065-0076-15

Pitch Axis

065-0076-15

Roll Axis

Fairchild C26A/C26B

KFC 400

065-0076-11

Yaw Axis

Fairchild SA227- AC/AT/BC/CC/DC

KFC 400

065-0076-15

Roll Axis

Learjet 31A

KFC 3100

065-0076-12

Pitch Axis

065-0076-14

Yaw Axis

065-0076-15

Roll Axis

Lockheed (Grumman) S-2 Tracker

KFC 325

065-0076-10

Special

Piper 400LS and PA-42-1000

KFC 400

065-0076-15

Yaw Axis

\n```\n\nRequirement: 1. Replace the autopilot servo actuator with an actuator that incorporates Mod 3, in accordance with procedures in the applicable maintenance manual.\n\n2. An actuator, listed in the Applicability Statement, that has not had Mod 3 incorporated may not be installed on any aeroplane.\n\nNote: FAA AD 98-08-20 Amdt 39-10469 refers.\n\nCompliance: 1. Within the next 100 hours time in service after the effective date of this directive.\n\n2. As of the effective date of this directive.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nThis airworthiness directive becomes effective on 18 June 1998.\n\nBackground: This directive requires the replacement of the autopilot servo actuator with a modified servo actuator. This is a result of the FAA receiving two reports of the affected actuators containing loose roll pins within the servo housing. Loose pins could fall out and become lodged in the output shaft, preventing this mechanism from disengaging.\n\nThe actions mandated by this directive are intended to prevent such an occurrence, which could result in an increased effort by the pilot to control the aircraft and possible loss of control of the affected flight control axis.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This directive remains narrowly focused on the original safety problem: preventing loose roll pins in certain KSA-470 autopilot servo actuators from causing jamming. It mandates a specific mechanical fix (Mod 3) and prohibits fitting unmodified units. It does not expand the subject matter beyond that original safety remedy, add unrelated obligations, or broaden applicability beyond the stated part/serial ranges."},"complexity_factors":["Single, focused safety action (replace units with Mod 3) with two clear requirements","Applicability defined by a contiguous range of part numbers (065-0076-10 through -15) and serial numbers (0001–3081)","Compliance timing has two simple conditions (within 100 flight hours; immediate prohibition on installation)","Cross-reference to FAA AD 98-08-20 (external document) for background/detail","Table of example aircraft types included but not limiting (adds minor interpretive step for operators checking fitment)","No nested exceptions or multiple conditional pathways"],"plain_english_summary":"**What this directive does (mechanical change)\n\n- **Replaces certain autopilot servo actuators**: Every Allied Signal Bendix/King KSA-470 servo actuator with part numbers 065-0076-10 through 065-0076-15 and serial numbers 0001–3081 must be replaced by an actuator that has “Mod 3” incorporated (Requirement 1).\n- **Bans unmodified units from being fitted**: Any actuator in the applicability list that has not had Mod 3 fitted may not be installed on any aircraft from the effective date onward (Requirement 2).\n- **Timing**: Replacement must be done within the next 100 flight hours after the directive takes effect; the installation ban is immediate as of the effective date (Compliance).\n\nWho is affected\n\n- Aircraft owners and operators that have any of the listed KSA-470 actuators installed (Applicability). The directive lists a number of aircraft types known to use these actuators, but it applies to the actuator part/serial ranges regardless of aircraft model.\n- Maintenance organisations and licensed engineers who carry out the replacement and approve the aircraft for return to service (Requirement 1).\n\nWhy the regulator says this matters (stated rationale)\n\n- The FAA reported two instances where roll pins inside affected actuators were loose. Loose pins can fall into the output shaft and prevent the actuator from disengaging, which could increase pilot control effort or lead to loss of control of the affected axis (Background). The directive points to FAA AD 98-08-20 for related details.\n\nPractical effects, who pays, who decides, and what changes\n\n- Who pays: aircraft owners/operators bear the cost of procuring Mod 3 actuators (or modifying existing units if allowed by the maintenance manual) and the labour/downtime for installation.\n- Who decides/executes: licensed maintenance personnel must perform the replacement “in accordance with procedures in the applicable maintenance manual” and sign off the work (Requirement 1).\n- Behaviour change required: operators must schedule and complete the replacement within 100 flight hours or remove the aircraft from operations if the actuator remains unmodified; aftermarket or used unmodified actuators cannot be installed after the effective date (Requirement 2).\n\nCosts, incentives and trade-offs\n\n- Direct costs: purchase or modification of actuators and maintenance labour; aircraft downtime while the work is done.\n- Incentives: maintenance providers and authorised parts suppliers gain immediate demand for Mod 3 actuators and installation services. Operators face an incentive to prioritise affected aircraft with higher utilisation.\n- Opportunity costs: time and funds spent on this action cannot be used elsewhere (other maintenance, upgrades). If Mod 3 parts are scarce, operators could face grounding or deferred operations.\n- Compliance burden and implementation risk: record-keeping and verification that the installed actuator has Mod 3; possible supply-chain delays for Mod 3 parts; minor risk of incorrect installation if procedures are not followed exactly.\n\nEffects on private enterprise and competition\n\n- Market effect: increased short-term demand for Mod 3 actuators and MRO (maintenance, repair, overhaul) services. If only a limited number of authorised suppliers or repair stations can produce or certify Mod 3 units, that may temporarily concentrate demand with those providers.\n- Prices/productivity: operators incur costs that could temporarily reduce productivity (aircraft out of service) and increase operating costs. MROs and parts suppliers may raise prices in response to demand, though the directive itself does not impose prices or supplier restrictions.\n- Contract freedom/installation choice: installers and operators lose the option to fit unmodified actuators in affected part/serial ranges; compliance is mandatory under airworthiness rules (Requirement 2).\n\nEnforcement and residual risks\n\n- This is a mandatory airworthiness directive: non-compliance results in the aircraft being unairworthy under the regulator's rules. The directive gives no discretionary exception beyond following the maintenance manual procedures.\n- Residual risk if compliance is delayed or done improperly: continued exposure to the reported failure mode (loose roll pins) until Mod 3 is correctly fitted.\n\nSource claims and testing them against practical costs\n\n- Source claim: replacing or modifying the actuator to Mod 3 prevents pins becoming loose and jamming the mechanism (Background). Mechanically, the intervention targets the reported root cause (loose roll pins).\n- Test against costs/trade-offs: the measure imposes upfront parts and labour costs and potential short-term operational disruption; it does not impose ongoing regulatory fees or new recurring obligations beyond ensuring only Mod 3 units are installed going forward.\n\nKey textual references: Applicability; Requirement 1 and 2; Compliance; Background.**"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a standard, targeted airworthiness directive addressing a specific safety defect in a particular aircraft component. The scope remains precisely limited to the identified autopilot servo actuator issue and has not expanded beyond its original safety purpose."},"complexity_factors":["Single, specific technical requirement with clear compliance deadline","Limited applicability scope (one manufacturer, specific part/serial number ranges)","Straightforward two-part requirement structure (replacement + installation ban)","No nested exceptions, conditional logic, or cross-references to other legislation beyond a single FAA AD reference for background","Technical table of affected aircraft adds visual complexity but does not create legal ambiguity","No defined terms section — uses plain technical language"],"plain_english_summary":"This AD mandates that operators of certain aircraft fitted with Allied Signal/Bendix/King KSA‑470 autopilot servo actuators replace the flawed unit with the modified \"Mod 3\" version within 100 flight hours and prohibits installing unmodified actuators. The actuator’s loose internal roll pins can jam the autopilot so it cannot be disengaged, risking loss of control. It affects operators of various business, commuter, and military types (e.g., Beech, Falcon, Learjet, Piper, Fairchild)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-inst-42-ksa-470-autopilot-servo-actuator","history":"/api/acts/ad-inst-42-ksa-470-autopilot-servo-actuator/history","analysis":"/api/acts/ad-inst-42-ksa-470-autopilot-servo-actuator/analysis","conflicts":"/api/acts/ad-inst-42-ksa-470-autopilot-servo-actuator/conflicts","importantCases":"/api/acts/ad-inst-42-ksa-470-autopilot-servo-actuator/important-cases","documents":"/api/acts/ad-inst-42-ksa-470-autopilot-servo-actuator/documents"}}