{"id":"F2006B07918","name":"Airworthiness Directives 2004 - Revocation and Remaking - Lycoming Piston Engines","slug":"airworthiness-directives-2004-revocation-and-remaking-lycoming-piston-engines","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":50956,"registerId":"commonwealth-F2006B07918-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 - Lycoming Piston Engines","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\nLycoming Piston Engines\n\nAD Name AD Number\n\nCentre Main Through Studs Re-Torqueing - CANCELLED AD/LYC/1 Amdt 1\n\nCast Counterweight - Replacement - CANCELLED AD/LYC/2\n\nIntercylinder Baffle Clamps - Replacement or Modification AD/LYC/3\n\nCylinder Head P/N 73114 - Cracking - CANCELLED AD/LYC/4 Amdt 1\n\nPiston P/N 71594 - Replacement - CANCELLED AD/LYC/5\n\nInstallation of Modified Hydraulic Tappet Body and Plunger Assemblies - AD/LYC/6 Amdt 2\n\nPropeller Shaft Oil Seal Ring - Inspection and Modification - CANCELLED AD/LYC/7\n\nExhaust Valve Guide - Inspection - CANCELLED AD/LYC/8 Amdt 1\n\nIntake Hose Clamps - Replacement - CANCELLED AD/LYC/9\n\nSuperseded by AD/LYC/15 - CANCELLED AD/LYC/10\n\nOil Pump Drive Shaft - Inspection and Replacement - CANCELLED AD/LYC/11\n\nCrankshaft Counterweight Bushings - Inspection and Replacement - AD/LYC/12 Amdt 2\n\nMagneto Drive Gear Cushion Retainer - Replacement - CANCELLED AD/LYC/13\n\nFuel and Oil Vent Restriction For A.C Lightweight Diaphragm Fuel Pumps - AD/LYC/14\n\nConnecting Rod - Replacement - CANCELLED AD/LYC/15 Amdt 4\n\nCrankshaft Propeller Flange - Inspection - CANCELLED AD/LYC/16\n\nDiaphragm - Fuel Injector Modification - CANCELLED AD/LYC/17 Amdt 2\n\nConnecting Rods - Replacement - CANCELLED AD/LYC/18\n\nMagneto Rotor Shaft Nut - Inspection - CANCELLED AD/LYC/19 Amdt 1\n\nCrankshaft Idler Gear Shafts - Replacement - CANCELLED AD/LYC/20\n\nAC Oil Filter Adapter Gasket - Replacement - CANCELLED AD/LYC/21\n\nConnecting Rod Bolt - Replacement - CANCELLED AD/LYC/22\n\nSupercharger Air Inlet Housing Assembly Inspection - CANCELLED AD/LYC/23\n\nIncreased Torque for Connecting Rod Bolt P/N 74644 - CANCELLED AD/LYC/24\n\nReduction Gear Assembly - Inspection and Modification - CANCELLED AD/LYC/25\n\nTurbine Housing - Inspection - CANCELLED AD/LYC/26\n\nFuel Line Heat Shield - Inspection - CANCELLED AD/LYC/27\n\nMain Bearing Retention and Oil Filter - Inspection - CANCELLED AD/LYC/28 Amdt 2\n\nExhaust Manifold Couplings - Replacement - CANCELLED AD/LYC/29\n\n  \nCarburettor Throttle Arm Screw - Retorque and Locking - CANCELLED AD/LYC/30\n\nFuel Line - Inspection and Clamp Installation - CANCELLED AD/LYC/31 Amdt 1\n\nCrankcase Bearing Dowel - CANCELLED AD/LYC/32 Amdt 2\n\nCrankcase Bearing Dowel - Replacement - CANCELLED AD/LYC/33 Amdt 1\n\nLimited Travel Valve Lifter - Replacement - CANCELLED AD/LYC/34\n\nCylinder Assemblies - Life Limits - CANCELLED AD/LYC/35 Amdt 1\n\nTurbocharger Exhaust System - Inspection and Modification - CANCELLED AD/LYC/36\n\nMandatory Replacement of Parts During Reconditioning - CANCELLED AD/LYC/37 Amdt 6\n\n7/16 inch Exhaust Valves and Guides - Retirement - CANCELLED AD/LYC/38\n\nCrankshaft Counterweight - Inspection and Replacement - CANCELLED AD/LYC/39\n\nFuel Line - Inspection and Clamp Installation - CANCELLED AD/LYC/40\n\nConnecting Rod - Replacement - CANCELLED AD/LYC/41\n\nTurbocharger Housing - Inspection and Replacement - CANCELLED AD/LYC/42\n\nTurbocharger Oil Line Reducer Bushing - Replacement - CANCELLED AD/LYC/43\n\nOil Pressure Filter - Inspection and Cover Modification - CANCELLED AD/LYC/44 Amdt 1\n\nConnecting Rod - Inspection - CANCELLED AD/LYC/45 Amdt 2\n\nPiston Pin P/N 69650 - Inspection - CANCELLED AD/LYC/46 Amdt 4\n\nTurbocharger Density Controller - CANCELLED AD/LYC/47 Amdt 5\n\nConnecting Rod High Tensile Bolts and High- Crush Bearings - Introduction - AD/LYC/48\n\nCANCELLED - AD/LYC/73 refers. - CANCELLED AD/LYC/49 Amdt 2\n\nStrengthened Connecting Rod Bolt - CANCELLED AD/LYC/50\n\nFuel Flow Divider Gasket - Inspection and/or Replacement - CANCELLED AD/LYC/51\n\nWastegate Valve Housing - Inspection - CANCELLED AD/LYC/52\n\nTurbocharger - Modification - CANCELLED AD/LYC/53\n\nTurbine Housing - Inspection - CANCELLED AD/LYC/54\n\nTappet Body - Inspection and Replacement - CANCELLED AD/LYC/55\n\nValve Rocker Arm Retaining Stud - Replacement - CANCELLED AD/LYC/56 Amdt 2\n\nConnecting Rod Cap and Bolt - Modification and Torque Increase - CANCELLED AD/LYC/57\n\nCrankshaft Replacement - CANCELLED AD/LYC/58 Amdt 1\n\nOil Pump - Inspection and Gear Replacement - CANCELLED AD/LYC/59\n\nHydraulic Tappet Replacement - CANCELLED AD/LYC/60\n\nFuel Pump to Fuel Injector Line - Replacement - CANCELLED AD/LYC/61\n\nFuel Injector Bellows Type Body Seal - Replacement - CANCELLED AD/LYC/62\n\nFuel Injector Diaphragm Part Number 2529471 - Inspection - CANCELLED AD/LYC/63 Amdt 1\n\nCarburettor Economiser Channel - Fitment of Brass Plug - CANCELLED AD/LYC/64\n\nFuel Injector Diaphragm Part Number 2529293 - Inspection - CANCELLED AD/LYC/65\n\n  \nTurbocharger Oil Drain Flange - Replacement - CANCELLED AD/LYC/66\n\nUpper Exhaust Valve Spring Retainer - Inspection - CANCELLED AD/LYC/67\n\nCrankshaft Flange Bolts - Replacement and Torque - CANCELLED AD/LYC/68\n\nUpper Exhaust Spring Seat and Hydraulic Lifter - Replacement - CANCELLED AD/LYC/69\n\nExhaust Valve Inspection - Helicopter Engines - CANCELLED AD/LYC/70\n\nPushrod - Inspection AD/LYC/71 Amdt 1\n\nTurbocharger Inspection and Plumbing Replacement - CANCELLED AD/LYC/72\n\nOil Pump Impellers - Replacement - CANCELLED AD/LYC/73 Amdt 2\n\nOil Pump Impellers - Replacement - CANCELLED AD/LYC/74\n\nCrankshaft Re-Nitriding - CANCELLED AD/LYC/75\n\nPropeller Attachment Flange AD/LYC/76 Amdt 6\n\nBendix Fuel Injection System, Diaphragm Type-Inspection - CANCELLED AD/LYC/77 Amdt 2\n\nThermostatic Oil Cooler Bypass Valve AD/LYC/78 Amdt 5\n\nCylinder Assembly - CANCELLED AD/LYC/79 Amdt 1\n\nTurbocharger Oil Inlet Adaptor Bushing AD/LYC/80\n\nOil Pump Impellers AD/LYC/81 Amdt 3\n\nCylinder Base Stud/Through Bolt Nut Torque - CANCELLED AD/LYC/82\n\nCrankshaft Flange AD/LYC/83\n\nEngine Driven Fuel Pump - CANCELLED AD/LYC/84\n\nExhaust Assembly AD/LYC/85 Amdt 1\n\nPropeller Governor Oil Line AD/LYC/86 Amdt 2\n\nChallenger Engineering Chrome Plated Cylinder Barrels AD/LYC/87\n\nWeld Repair Crankcase Inspection - CANCELLED AD/LYC/88\n\nCrankshaft Gear AD/LYC/89 Amdt 3\n\nFuel Injection Supply Lines AD/LYC/90\n\nCrankshaft Removal/Inspection AD/LYC/91\n\nMandatory Replacement of Parts - CANCELLED AD/LYC/92\n\nConnecting Rods - CANCELLED AD/LYC/93\n\nro Accessories Inc. Engine Driven Fuel Pumps - CANCELLED AD/LYC/94\n\nTurbocharger Density Controller Adjustment AD/LYC/95\n\nUnapproved Camshaft Repairs AD/LYC/96\n\nConnecting Rod Bolt Inspection AD/LYC/97\n\nPush Rod Inner Diameter Scoring AD/LYC/98\n\nDiaphragm Fuel Pumps AD/LYC/99\n\nPiston Pin P/N LW-14077 AD/LYC/100\n\nSuperior Cylinders AD/LYC/101 Amdt 1\n\n  \nCrankshaft Internal Inspection AD/LYC/102 Amdt 2\n\nSlick Magneto Inspection AD/LYC/103\n\nCrankshaft Drive Gear Bolts AD/LYC/104\n\nOil Filter Converter Plate Gasket AD/LYC/105 Amdt 1\n\nRYCO R14 Oil Filters AD/LYC/106\n\nCrankshaft Replacement AD/LYC/107 Amdt 2\n\nCrankshaft Material Inspection AD/LYC/108\n\nCrankshaft Gear Bolt AD/LYC/109 Amdt 2","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":4,"scope_assessment":{"changed":false,"description":"The instrument does not change the substantive content of the listed ADs: it revokes them and remakes each in exactly the same form as the latest published edition (see Note). This is an administrative republishing exercise rather than a change in technical scope; some entries are already marked CANCELLED in Schedule 1, reflecting prior status rather than a new substantive change."},"complexity_factors":["Large number of listed ADs in Schedule 1 increases tracking and administrative burden for operators and regulator (Schedule 1).","Many entries carry status annotations (e.g. CANCELLED, Amdt, Superseded), creating potential ambiguity about which instruments remain active (Schedule 1).","Action is procedural—revocation then remaking each AD as a separate instrument—requiring careful replication of existing texts to avoid drafting errors (Note).","Decision and legal authority rest with a CASA delegate under subregulation 39.001(1), concentrating discretionary action in a delegated office (opening recital).","Operators must update compliance records and maintenance procedures to match republished ADs, imposing modest recurring compliance costs (mechanical effect described in instrument)."],"plain_english_summary":"This instrument, signed under subregulation 39.001(1) CASR 1998 by a CASA delegate, revokes the Airworthiness Directives listed in Schedule 1 and remakes each as a separate instrument in the same form as their latest published editions. It affects operators, maintenance organisations and parts suppliers of Lycoming piston‑engined aircraft. Mechanically it republishes existing ADs; operators bear compliance and record‑keeping costs, CASA (through its delegate) decides issuance, and the instrument does not change technical requirements (see Schedule 1 and Note)."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"The legislation maintains its original administrative purpose — to revoke and remake Airworthiness Directives as required by the Civil Aviation Safety Regulations. The scope has not expanded beyond this housekeeping function, though the volume of affected directives (109) reflects the accumulated regulatory history of Lycoming engine safety oversight rather than an expansion of regulatory intent."},"complexity_factors":["Simple administrative structure: single operative clause with two straightforward actions (revocation and remaking)","No conditional logic or nested exceptions in the instrument itself","Heavy reliance on external documents: 109 separate Airworthiness Directives are incorporated by reference but not reproduced in the text","Minimal defined terms: only standard regulatory references (subregulation 39.001(1))","Tabular schedule format makes the list of affected instruments readable but creates length (109 entries)","No cross-references to other legislation beyond the enabling regulation (CASR 1998)"],"plain_english_summary":"This CASA order consolidates and reissues safety rules for Lycoming piston engines by revoking 109 existing Airworthiness Directives and remaking them as fresh legal instruments, preserving their force under current aviation law. It affects owners, operators and maintenance personnel of aircraft with Lycoming piston engines: most listed ADs are now marked cancelled, while a subset remains active and must be complied with to keep affected aircraft legally airworthy."}},"importantCases":[],"_links":{"self":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-lycoming-piston-engines","history":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-lycoming-piston-engines/history","analysis":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-lycoming-piston-engines/analysis","conflicts":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-lycoming-piston-engines/conflicts","importantCases":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-lycoming-piston-engines/important-cases","documents":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-lycoming-piston-engines/documents"}}