{"id":"F2006B07732","name":"Airworthiness Directives 2004 - Revocation and Remaking - Ayres Thrush (Snow) Commander Series Aeroplanes","slug":"airworthiness-directives-2004-revocation-and-remaking-ayres-thrush-snow-commander-series-aeroplanes","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":50464,"registerId":"commonwealth-F2006B07732-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"Airworthiness Directives 2004 - Revocation and Remaking - Ayres Thrush (Snow) Commander Series Aeroplanes","content":"Airworthiness Directives 2004\n\nI, DAVID ALAN VILLIERS, delegate of the Civil Aviation Safety\n\nAuthority, acting under subregulation 39.001 (1) of the Civil\n\nAviation Safety Regulations 1998:\n\n(a) revoke the Airworthiness Directives mentioned in\n\nSchedule 1; and\n\n(b) make, as separate instruments, each Airworthiness\n\nDirective mentioned in Schedule 1 and attached.\n\n![](image.001.png)\n\nDavid Villiers\n\nDelegate of the Civil Aviation Safety Authority\n\n20 December 2004\n\nNote: Each attached Airworthiness Directive is being re-made in exactly the\n\nsame form as appears in the latest published edition of the Directive.\n\n  \nSchedule 1 Revocation and Remaking of\n\nAirworthiness Directives\n\nAyres Thrush (Snow) Commander Series Aeroplanes\n\nAD Name AD Number\n\nMixture Control Lever Quadrant - Modification AD/AC-SNOW/1\n\nAgricultural Equipment Boom Support - Modification AD/AC-SNOW/2\n\nMain Landing Gear Axle - Inspection and Modification AD/AC-SNOW/3\n\nDeflector Cable Assembly - Modification AD/AC-SNOW/4\n\nFin Bracing Wire Fittings - Modification AD/AC-SNOW/5\n\nTurn and Bank Indicator Installation - Modification AD/AC-SNOW/6\n\nSeat Installation - Reinforcement - CANCELLED AD/AC-SNOW/7 Amdt 2\n\nInstallation of Padding to Cockpit Upper Cross Tube - Modification AD/AC-SNOW/8\n\nSeat Travel Restriction - Modification AD/AC-SNOW/9\n\nSafety Harness - Installation AD/AC-SNOW/10\n\nCarburettor Air Selector Valve Assembly - Inspection AD/AC-SNOW/11\n\nRudder Control Surface Upper Hinge - Inspection and Modification AD/AC-SNOW/12\n\nHorizontal Stabiliser Spar - Fatigue Inspection AD/AC-SNOW/13\n\nWing Spar and Wing Attachments AD/AC-SNOW/14 Amdt 4\n\nForward Fuselage Upper Longerons - Inspection and Modification AD/AC-SNOW/15\n\nRudder Horn Balance/Leading Edge Intersection AD/AC-SNOW/16 Amdt 1\n\nOuter Wing Huck Bolts AD/AC-SNOW/17\n\nWing Front Spar Corrosion AD/AC-SNOW/18\n\nAileron Hinge Brackets - CANCELLED AD/AC-SNOW/19\n\nAileron Hinge Bracket Bolts AD/AC-SNOW/20\n\nVertical Tail Attachment Bracket AD/AC-SNOW/21\n\nHorizontal Stabiliser Front and Rear Spar and Attach Fittings AD/AC-SNOW/22\n\nVertical Fin Rear Spar AD/AC-SNOW/23\n\nWing Spar AD/AC-SNOW/24 Amdt 3\n\nMLG to Fuselage Attach Bolts AD/AC-SNOW/25","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":2,"scope_assessment":{"changed":false,"description":"This instrument does not broaden the substantive scope of the safety requirements. It revokes and re-makes the listed ADs \"in exactly the same form\" as their latest published editions, so the technical obligations on operators remain unchanged. The only scope change evident in the Schedule is the cancellation notation for two AD entries (AD/AC-SNOW/7 and AD/AC-SNOW/19), which reduces obligations where those cancellations apply; otherwise there is no material expansion of purpose beyond administrative re-issuance."},"complexity_factors":["Single short instrument (one page) with a single operative paragraph (revocation and re-making).","Schedule lists 25 AD entries (including two marked CANCELLED) but does not change substantive obligations.","Relies on a single statutory power: subregulation 39.001(1) of the Civil Aviation Safety Regulations 1998.","No nested conditional logic or multiple cross-references within the instrument itself (attached ADs are stated to be identical to published editions).","Some AD entries show prior amendments (e.g. 'Amdt 2', 'Amdt 3') but this instrument does not rework those amendments—merely re-issues the latest edition."],"plain_english_summary":"**What this instrument does (mechanically)\n\n- Revokes a group of existing Airworthiness Directives (ADs) that apply to Ayres Thrush (Snow) Commander series aeroplanes.\n- Re-makes each revoked AD as a separate, standalone legal instrument in exactly the same form as the latest published edition of that AD. In short: old AD instruments are revoked and the same AD requirements are re-issued as individual instruments.\n- Two items in the schedule are marked \"CANCELLED\" (AD/AC-SNOW/7 and AD/AC-SNOW/19); those entries are not being re-made.\n\nWho this affects\n\n- Aircraft owners and operators of Ayres Thrush (Snow) Commander series aeroplanes. They must comply with the ADs that remain in force.\n- Maintenance organisations and engineers who perform inspections, modifications or repairs required by those ADs.\n- The Civil Aviation Safety Authority (CASA) and its delegate who manage, publish and enforce ADs.\n\nWhy it matters (practical effect)\n\n- The substantive safety requirements (inspections, modifications, installations and other mandatory actions) are unchanged by this instrument because each AD is re-issued in the same form. Operators who were already complying will continue to have the same actions and schedules to follow.\n- The immediate administrative effect is to replace older AD instruments with newly issued, separate AD instruments. This can affect record-keeping: operators and maintainers should reference the re-made AD instrument numbers and editions when showing compliance.\n\nLegal basis and mechanics\n\n- The delegate acts under subregulation 39.001(1) of the Civil Aviation Safety Regulations 1998 to revoke and re-make the ADs.\n- The instrument contains a Schedule listing 25 AD entries (including two marked CANCELLED). Each listed AD is revoked and then re-made as a separate instrument attached to this decision. The instrument states each attached AD is identical to its latest published edition.\n\nSource's stated purpose and a practical test of costs, incentives and implementation\n\n- The instrument expressly re-makes the ADs \"in exactly the same form\" as their latest published editions. The stated purpose is therefore procedural (re-issuing ADs) rather than changing safety requirements.\n- Costs and incentives: there is no change to the substantive compliance burden on operators, because the AD requirements remain the same. There is a small administrative cost to operators and maintainers to update references, compliance records, and paperwork to cite the new instrument versions. CASA bears the administrative cost of issuing the separate instruments and maintaining publication records.\n- Bureaucratic discretion and implementation risk: the delegate exercises statutory power to revoke and re-make instruments. Because the re-made ADs are identical to published editions, the risk of inadvertent substantive change is low; the main implementation risk is administrative (document tracking, ensuring operators use the correct instrument references).\n- Effects on private choice and markets: there is no change to operators' technical obligations or to market access for maintenance providers. Competitive effects are minimal because the rule content is unchanged. If any ADs were cancelled (as two are marked), that reduces obligations for affected operators.\n\nWho pays, who decides, and what behaviour changes\n\n- Who pays: operators and maintenance organisations bear any ongoing compliance costs required by the ADs; CASA bears the administrative cost of re-issuing and publishing instruments. The re-making itself does not create new substantive costs.\n- Who decides: a CASA delegate (David Alan Villiers, by this instrument) exercises the statutory power under the referenced subregulation to revoke and re-make the ADs.\n- Behaviour changes: in practice, operators should check their compliance records and update citations to the newly re-made AD instruments. No change in inspection or modification behaviour is mandated except where specific ADs are listed as cancelled.\n\nNotable specifics in the Schedule\n\n- The Schedule lists 25 AD entries covering items such as mixture control lever quadrant, main landing gear axle inspection/modification, wing spar and attach fittings, stabiliser and tail fittings, seat installations, safety harnesses, carburettor air selector inspection, and others.\n- AD/AC-SNOW/7 (Seat Installation - Reinforcement) and AD/AC-SNOW/19 (Aileron Hinge Brackets) are marked as CANCELLED in the Schedule.\n\nBottom line\n\nThis instrument is an administrative re-issuance: it revokes an existing set of AD instruments for Ayres Thrush (Snow) Commander aeroplanes and re-issues them, unchanged in substance, as separate AD instruments. Operators should update records and references but will generally face the same technical obligations as before."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This instrument performs a pure administrative consolidation. The scope remains exactly as intended — maintaining airworthiness requirements for a specific aircraft type. There is no expansion of substantive obligations; the 'revoke and remake' mechanism preserves the status quo while improving legal instrument architecture."},"complexity_factors":["Very short instrument (under 500 words)","Only one operative provision with two simple limbs (revoke and remake)","No defined terms section — relies on external regulations (Civil Aviation Safety Regulations 1998)","No conditional logic or nested exceptions","Straightforward tabular schedule listing 25 directives by name and number","Two directives marked \"CANCELLED\" add minor administrative complexity","Cross-reference to subregulation 39.001(1) of CASR 1998 is the only external citation"],"plain_english_summary":"This CASA safety order cancels 25 current Airworthiness Directives for Ayres Thrush (Snow) Commander agricultural aircraft and immediately remakes them as 25 separate legal instruments. It affects owners, operators and maintenance organisations responsible for these crop-dusters.\n\nThe technical requirements remain unchanged; this is legal housekeeping to put each mandatory safety directive into its own standalone document, making future updates and enforcement simpler."}},"importantCases":[],"_links":{"self":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-ayres-thrush-snow-commander-series-aeroplanes","history":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-ayres-thrush-snow-commander-series-aeroplanes/history","analysis":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-ayres-thrush-snow-commander-series-aeroplanes/analysis","conflicts":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-ayres-thrush-snow-commander-series-aeroplanes/conflicts","importantCases":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-ayres-thrush-snow-commander-series-aeroplanes/important-cases","documents":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-ayres-thrush-snow-commander-series-aeroplanes/documents"}}