{"id":"F2006B08565","name":"AD/CIRRUS/3 - Roll and Yaw Trim Cartridges Self-Locking Nuts","slug":"ad-cirrus-3-roll-and-yaw-trim-cartridges-self-locking-nuts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51401,"registerId":"commonwealth-F2006B08565-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CIRRUS/3 - Roll and Yaw Trim Cartridges Self-Locking Nuts","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)  \n\nAIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\nCirrus Design SR20 and SR22 Series Aeroplanes\n\nAD/CIRRUS/3 Roll and Yaw Trim Cartridges Self-Locking Nuts\n\n  \n13/2002\n\nDM\n\nApplicability: Model SR20, serial numbers 1005 through 1241, except 1235, 1237, and 1238.\n\nModel SR22, serial numbers 0002 through 0333, except 0309, 0322, 0323, and 0328.\n\nRequirement: Replace the self- locking retaining nut on the yaw trim cartridge and the roll trim cartridge with a new self- locking retaining nut, MS21044N3.\n\nNote: FAA AD 2002-21-02 Amdt 39-12908 refers.\n\nCompliance: Within 10 hours time in service after 8 November 2002.\n\nThis Airworthiness Directive becomes effective on 30 October 2002.\n\nBackground: The FAA received a report that, during flight test, the self- locking retaining nut on the yaw trim cartridge came off, and the pilot lost right rudder control. This Directive requires retaining nut replacement on both roll and yaw trim cartridges with new self- locking nuts with a higher axial load capability. Loss of a retaining nut during flight could result in jamming of corresponding flight control system, and loss of control of the aircraft.\n\n![Signature of David Alan Villiers Delegate of the Civil Aviation Safety Authority](image.002.jpeg)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 24 October 2002\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 30 October 2002.\n\n  \nPage 1 of 1","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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a targeted airworthiness directive addressing a specific mechanical defect in specific aircraft. It has not expanded beyond its original safety purpose."},"complexity_factors":["Single, specific mechanical action required (nut replacement)","Limited applicability — only 2 aircraft models with explicitly listed serial number ranges","No nested exceptions or conditional logic beyond simple serial number exclusions","Clear, single compliance deadline (10 hours time in service after specified date)","No cross-references to other legislation beyond a single note referencing the related FAA directive","Short document (1 page) with minimal defined terms"],"plain_english_summary":"CASA orders owners/operators of certain Cirrus SR20 (S/N 1005–1241, excl. 1235, 1237, 1238) and SR22 (S/N 0002–0333, excl. 0309, 0322, 0323, 0328) to replace the self‑locking nuts on the roll and yaw trim cartridges with MS21044N3 nuts within 10 hours' flying time after 8 Nov 2002.  \n\nThe change prevents loose nuts from jamming trim controls and risking loss of control, following an FAA in‑flight failure."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD remains tightly focused on correcting a single safety defect reported in flight testing: removal/loss of a self-locking retaining nut on trim cartridges. It does not expand beyond that remedial purpose (it prescribes a single part replacement on specified serial-numbered aircraft). There is no evidence in the text that the AD's scope grew beyond the original safety-correction objective."},"complexity_factors":["Very short document (single-page AD)","Clear applicability via serial-number ranges with a few explicit exclusions","Single mandatory action: replace two retaining nuts with specified part MS21044N3","One short, concrete compliance deadline (within 10 hours TIS after specified date)","Minor cross-reference to CAR 1998 subregulation 39.1(1) and to FAA AD 2002-21-02 (informational)","No layered conditions, no multiple exceptions or nested conditional logic"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- This is an Airworthiness Directive (AD) that orders a specific hardware change on certain Cirrus Design SR20 and SR22 aeroplanes. (See the \"Applicability\" section for the exact serial numbers affected.)\n- The \"Requirement\" is simple: replace the self-locking retaining nut on both the yaw-trim cartridge and the roll-trim cartridge with a specified part number, MS21044N3.\n- The \"Compliance\" deadline is short: the replacement must be done within 10 hours time-in-service after 8 November 2002. The AD became effective on 30 October 2002.\n\n**Who it affects**\n\n- Owners and operators of the listed Cirrus SR20 and SR22 aircraft (specific serial numbers are given in the Applicability section). Excluded serial numbers are listed as exceptions in that same section.\n- Maintenance organisations, mechanics and parts suppliers who perform or supply the mandated replacement.\n\n**Why it matters (stated purpose and mechanical effect)**\n\n- The Background section reports an in-flight incident where a self-locking retaining nut on a yaw-trim cartridge came off during flight, causing loss of right rudder control.\n- The AD requires replacement nuts with a higher axial load capability. The declared safety rationale is to prevent loss of a retaining nut, which could jam the flight control system and lead to loss of control.\n\n**Who pays, who decides, and what behaviour changes**\n\n- Who pays: aircraft owners/operators pay for the replacement parts (MS21044N3) and labour. If maintenance is contracted out, operators pay the maintenance provider.\n- Who decides: the Civil Aviation Safety Authority (CASA) delegate issued the AD under subregulation 39.1(1) of the Civil Aviation Regulations 1998; compliance decisions (when and where the work is done) are made by the operator/maintenance organisation subject to the AD timing.\n- Behaviour changes: operators must schedule the replacement promptly (within the 10-service-hour window) and record compliance in the aircraft maintenance log. Maintenance providers must stock or source the specific MS21044N3 nuts and install them per standard practice.\n\n**Costs, incentives and trade-offs**\n\n- Direct costs: purchase of specified nuts and labour to replace two nuts per aircraft (roll and yaw cartridges). These are concentrated costs borne by affected owners/operators.\n- Supply and scheduling risk: the short compliance window elevates the importance of parts availability and may force operators to ground aircraft briefly or reassign flights to meet the deadline. Independent MROs (maintenance, repair and overhaul businesses) may capture additional business from operators who outsource the work.\n- Implementation risk: improper installation or use of incorrect nuts could leave the unsafe condition uncorrected. The AD specifies the part number (MS21044N3) to reduce ambiguity.\n- Administrative burden: operators must ensure maintenance records document the replacement to demonstrate compliance; regulators may audit records.\n\n**How it affects markets and private choice**\n\n- Competition and suppliers: specifying a military/specification part number (MS21044N3) focuses demand on suppliers who carry that part; it does not mandate a single proprietary supplier but does narrow acceptable substitutes.\n- Productivity and operation: short-term aircraft availability may be reduced while replacements occur; beyond the replacement, normal operations resume.\n- Contract freedom: operators remain free to choose an approved maintenance provider, but must meet the AD requirement and deadline.\n\n**Net scope and mechanism**\n\n- The AD is narrowly targeted: it applies only to listed serial numbers of SR20 and SR22 aeroplanes and requires a single, defined hardware swap intended to mitigate a particular mechanical failure mode (loss of the retaining nut leading to possible flight control jam). (See the \"Applicability\", \"Requirement\" and \"Background\" sections.)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-cirrus-3-roll-and-yaw-trim-cartridges-self-locking-nuts","history":"/api/acts/ad-cirrus-3-roll-and-yaw-trim-cartridges-self-locking-nuts/history","analysis":"/api/acts/ad-cirrus-3-roll-and-yaw-trim-cartridges-self-locking-nuts/analysis","conflicts":"/api/acts/ad-cirrus-3-roll-and-yaw-trim-cartridges-self-locking-nuts/conflicts","importantCases":"/api/acts/ad-cirrus-3-roll-and-yaw-trim-cartridges-self-locking-nuts/important-cases","documents":"/api/acts/ad-cirrus-3-roll-and-yaw-trim-cartridges-self-locking-nuts/documents"}}