{"id":"F2006B07722","name":"Airworthiness Directives 2004 - Revocation and Remaking - Allison Turbine Engines - 250 Series","slug":"airworthiness-directives-2004-revocation-and-remaking-allison-turbine-engines-250-series","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":50454,"registerId":"commonwealth-F2006B07722-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 - Allison Turbine Engines - 250 Series","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\nAllison Turbine Engines - 250 Series\n\nAD Name AD Number\n\nLife Limited Components - CANCELLED AD/AL 250/1 Amdt 12\n\nCompressor Front Bearing Thrust Washer and Spring - Replacement AD/AL 250/2\n\nOil Filter By-Pass Valve Poppet Guide - Replacement AD/AL 250/3\n\nSixth Stage Compressor Blades - Modification AD/AL 250/4\n\nEngine Compressor - Modifications AD/AL 250/5 Amdt 1\n\nPower Turbine Governor - Modification AD/AL 250/6 Amdt 1\n\nCANCELLED AD/AL 250/7\n\nHelical Power Train Drive Gear Internal Spline Inspection AD/AL 250/8 Amdt 1\n\nEngine Operating Restrictions to Reduce Torque-Meter Shaftgears Stress AD/AL 250/9\n\nCANCELLED AD/AL 250/10\n\nEngine Improvement - Introduction of Blue Ribbon Modifications AD/AL 250/11 Amdt 3\n\nPc Filter Flanged Insert - Inspection AD/AL 250/12 Amdt 2\n\nImproved Indicating Magnetic Drain Plugs - Introduction AD/AL 250/13\n\nCompressor Wheels, Glass Bead Peening AD/AL 250/14\n\nEngine Parts - Time Limitations - CANCELLED AD/AL 250/15 Amdt 9\n\nCeco Fuel Control and Governor External Plug and Lever - Replacement AD/AL 250/16\n\nLife Limited Components - CANCELLED AD/AL 250/17 Amdt 5\n\nCompressor Bleed Valve Orifice - Installation AD/AL 250/18\n\nFuel System - Power Turbine Governor to Control Fuel Tube Clamp - Installation AD/AL 250/19\n\nFuel Pump Drive Shaft - Inspection AD/AL 250/20 Amdt 1\n\nCeco F.C.U. Throttle Shaft and Governor Quadrant and Shaft Assembly - AD/AL 250/21\n\nCANCELLED AD/AL 250/22\n\nEngine Parts - Time Limitations - CANCELLED AD/AL 250/23 Amdt 3\n\nLife Limited Components - CANCELLED AD/AL 250/24 Amdt 5\n\nPower Turbine Outer Coupling Nut - Inspection AD/AL 250/25 Amdt 1\n\nThird Stage Turbine Wheel Replacement - CANCELLED AD/AL 250/26 Amdt 1\n\nCompressor Bleed Valve Strainer - Installation AD/AL 250/27\n\nN1 and N2 Operating Restrictions and Placard Installation - CANCELLED AD/AL 250/28 Amdt 1\n\nCANCELLED AD/AL 250/29 Amdt 1\n\n  \nFuel System - Fuel Pump to Control and Fuel Control to Pump By-Pass Tube AD/AL 250/30\n\nFuel System - Check Valve Assembly - Installation AD/AL 250/31\n\nEngine Fuel and Control, Electrical Harness - Replacement AD/AL 250/32\n\nFourth Stage Compressor Wheel - Retirement AD/AL 250/33\n\nN2 Overspeed Protection: De-Activation and Replacement - CANCELLED AD/AL 250/34\n\nLife Limited Components - CANCELLED AD/AL 250/35 Amdt 2\n\nLife Limited Components - CANCELLED AD/AL 250/36 Amdt 4\n\nThird Stage Turbine Wheel - Replacement AD/AL 250/37\n\nIdler Gearshafts - Replacement AD/AL 250/38\n\nCancelled AD/AL 250/39\n\nThird Stage Turbine Wheel - Overheat and Replacement - CANCELLED AD/AL 250/40 Amdt 1\n\nThird Stage Turbine Wheel - Inspection and RPM Operational Restrictions AD/AL 250/41 Amdt 5\n\nCANCELLED AD/AL 250/42\n\nSecond Stage Turbine Nozzle AD/AL 250/43 Amdt 3\n\nTurbine Support and Exhaust Collector Flow Divider Cracking - CANCELLED AD/AL 250/44 Amdt 1\n\nPower Turbine Inner and Outer Coupling Shaft - Replacement AD/AL 250/45\n\nPower Turbine Governor (Bendix) - Inspection of Drive Shaft AD/AL 250/46 Amdt 1\n\nFirst Stage Turbine Wheel P/N 6853306 - Replacement AD/AL 250/47\n\nFourth Stage Turbine Nozzle P/N 6898694 - Inspection AD/AL 250/48 Amdt 3\n\nN2 Overspeed Control System - Disarming AD/AL 250/49\n\nN2 Overspeed Control Assembly - Addition of Lockwashers to Ground Jumper AD/AL 250/50 Amdt 1\n\nHigh Pressure Fuel Control Filter Assembly - Modification AD/AL 250/51 Amdt 1\n\nEngine Fuel and Control - Bendix Fuel Control Assemblies and Power Turbine AD/AL 250/52 Amdt 1\n\nCompressor Mount Assembly AD/AL 250/53 Amdt 1\n\nEngine Turbine Assembly No. 8 Bearing U-Ring Installation AD/AL 250/54 Amdt 1\n\nGas Producer Rotor Assembly - Tie Bolt P/N 6843388, 6876991 and 6889320 AD/AL 250/55 Amdt 3\n\nEngine Quick Disconnect Magnetic Plugs - Inspection of Lockpins and Slots for AD/AL 250/56 Amdt 1\n\nTurbine Shaft - Inspection - CANCELLED AD/AL 250/57\n\nGearbox Assembly - PTO Helical Gearshaft Assembly - Replacement AD/AL 250/58 Amdt 2\n\nOuter Combustion Case Assemblies P/N 6899237 and 23009569 AD/AL 250/59 Amdt 3\n\nNI Shafting - Inspection - CANCELLED AD/AL 250/60 Amdt 2\n\nGas Producer Turbine Assembly and Second Stage Nozzle Seal AD/AL 250/61 Amdt 3\n\nFourth Stage Nozzle Assembly - Replacement AD/AL 250/62 Amdt 1\n\nTurbine to Compressor Coupling Shaft Inspection and Modifications to Prevent AD/AL 250/63 Amdt 7\n\nInternal Energy Absorbing Ring AD/AL 250/64 Amdt 3\n\nEngine Power and Accessory Gearbox - New Magnetic Plug Introduction AD/AL 250/65\n\n  \nSecond Stage Turbine Wheel AD/AL 250/66 Amdt 2\n\nIncreased Labyrinth Seal Clearance Second Stage Turbine Nozzle AD/AL 250/67 Amdt 1\n\nTurbine to Compressor Coupling Shaft Inspection and Modifications to Prevent AD/AL 250/68 Amdt 2\n\nInstallation of Internal Energy Absorbing Ring AD/AL 250/69\n\nNo. 8 Bearing Scavenge Line Air/Oil Separator AD/AL 250/70\n\nTurbine Splined Adapter Locknut Torque AD/AL 250/71\n\nNo. 8 Bearing Oil Supply Tube AD/AL 250/72 Amdt 1\n\nBendix Power Turbine Governor AD/AL 250/73 Amdt 2\n\nLife Limited Components - CANCELLED AD/AL 250/74\n\nLife Limited Components - CANCELLED AD/AL 250/75\n\nFalcon Helicopters AD/AL 250/76\n\nThird Stage Turbine Wheel P/N 23001977 AD/AL 250/77\n\nSuperior Turbine Bearings AD/AL 250/78\n\nFuel Control Bellows Replacement AD/AL 250/79\n\nGearbox - Torquemeter Gearshaft Assembly AD/AL 250/80 Amdt 1\n\nThird Stage Turbine Wheels AD/AL 250/81\n\nHydromechanical Unit Power Lever Angle Potentiometer AD/AL 250/82\n\nThird-Stage Turbine Wheels AD/AL 250/83","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument performs exactly the function described in its title — revoking and remaking ADs for Allison 250 engines. The scope is limited to administrative consolidation of existing safety requirements. No expansion beyond the original regulatory purpose of maintaining current airworthiness standards."},"complexity_factors":["Single, clear operative provision with two straightforward actions (revocation and remaking)","No defined terms section — relies on external understanding of 'Airworthiness Directive' and 'Civil Aviation Safety Regulations 1998'","Extensive schedule (83 items) but purely tabular/list format with no conditional logic","No cross-references to other legislation beyond the enabling regulation (subregulation 39.001(1))","Simple binary status for each item (active or cancelled)","No exceptions, nested conditions, or interpretive provisions"],"plain_english_summary":"CASA is tidying its airworthiness database for Allison 250 turbine engines by revoking 83 existing Airworthiness Directives and immediately reissuing most as fresh legal instruments, while permanently cancelling a subset that are obsolete.  \n\nThis is an administrative housekeeping action affecting helicopter/aircraft operators, owners and maintenance providers; remade ADs are identical to the latest versions, so it updates legal formality without changing safety requirements."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"No substantive change. The instrument revokes listed ADs and re-issues them unchanged (see Schedule 1 and accompanying note), preserving existing compliance obligations; the change is administrative and affects how the directives are recorded and referenced rather than their substance."},"complexity_factors":["Delegated action under subregulation 39.001(1) — legal authority is concentrated in the CASA delegate rather than Parliament (text: 'acting under subregulation 39.001 (1)').","Large Schedule 1 listing many ADs (including multiple 'CANCELLED' items and amended entries) increases administrative mapping between old and re-made instruments.","Note requiring each re-made AD to match the 'latest published edition' ties legal force to external published materials — creates dependency on publication records for authoritative content.","Procedure is mainly administrative (revocation and separate re-making) so substantive obligations remain but recordkeeping and cross-referencing burdens fall on operators and maintainers.","Potential for temporary confusion or compliance risk from reissued instrument identifiers and cancelled entries, requiring careful implementation by regulators and industry (Schedule 1 structure and note)."],"plain_english_summary":"This instrument revokes the Airworthiness Directives listed in Schedule 1 and re-issues each as a separate directive in the same form as the latest published edition (action taken under subregulation 39.001(1)). It affects owners, operators and maintenance organisations using Allison 250-series turbine engines by preserving existing mandatory inspection, modification and retirement requirements. The practical effect is administrative continuity: regulated parties must continue to comply and update records, while the CASA delegate carries out the re-issuance."}},"importantCases":[],"_links":{"self":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-allison-turbine-engines-250-series","history":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-allison-turbine-engines-250-series/history","analysis":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-allison-turbine-engines-250-series/analysis","conflicts":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-allison-turbine-engines-250-series/conflicts","importantCases":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-allison-turbine-engines-250-series/important-cases","documents":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-allison-turbine-engines-250-series/documents"}}