{"id":"F2006B07979","name":"Airworthiness Directives 2004 - Revocation and Remaking - Pratt and Whitney Turbine Engines - JT9D Series","slug":"airworthiness-directives-2004-revocation-and-remaking-pratt-and-whitney-turbine-engines-jt9d-series","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115027,"registerId":"commonwealth-F2006B07979-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"Airworthiness Directives 2004 - Revocation and Remaking - Pratt and Whitney Turbine Engines - JT9D 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\nPratt and Whitney Turbine Engines - JT9D Series\n\nAD Name AD Number\n\nLife Limits - Engine Rotating Parts - CANCELLED AD/JT9D/1 Amdt 1\n\nLife Limits - Engine Rotating Parts - CANCELLED AD/JT9D/2 Amdt 1\n\nDiffuser Case AD/JT9D/3\n\nIncorporation of Main Gearbox Spray Nozzles AD/JT9D/4\n\nReplacement of Main Gearbox Assembly Face Seals AD/JT9D/5\n\nEngine Tailpipe/Exhaust Case - Inspection for Oil Leakage AD/JT9D/6\n\nNo. 3 Bearing Breather Temp Check and Replacement of Main Bearing Breather AD/JT9D/7\n\nFan Blade - Inspection and Blending AD/JT9D/8\n\nFifth Stage Turbine Hubs - Reduction of Cyclic Life AD/JT9D/9\n\nMain Gearbox Assembly - Magnetic Plug Inspection AD/JT9D/10\n\nNo. 4 Bearing Compartment AD/JT9D/11\n\nFifteenth Stage Compressor Discs AD/JT9D/12 Amdt 1\n\nLow Pressure Turbine Anti-Rotation Pins AD/JT9D/13 Amdt 3\n\nDiffuser Case Rear Rail Cracking AD/JT9D/14 Amdt 1\n\nHigh Pressure Turbine Airseal AD/JT9D/15\n\nHPC Variable Stator Synchronising Ring Runner Clearance AD/JT9D/16\n\nFan Containment Shield AD/JT9D/17 Amdt 2\n\nLow Pressure Turbine Airseal AD/JT9D/18\n\nSurge Margin Improvements AD/JT9D/19 Amdt 2\n\nDiffuser Case Strut Inserts AD/JT9D/20\n\nDrain Tube Replacement AD/JT9D/21\n\nFirst Stage High Pressure Turbine Airseal AD/JT9D/22\n\nFirst Stage High Pressure Turbine Airseal AD/JT9D/23\n\nHPC Turbine Drive Shafts AD/JT9D/24\n\nFan Blade Inspection/Revised Shroud Angle AD/JT9D/25\n\nDiffuser Case Inspection AD/JT9D/26\n\nFan Exit Case Cover Modification AD/JT9D/27\n\nLPT Vane Hardware AD/JT9D/28\n\nTurbine Exhaust Case AD/JT9D/29 Amdt 2\n\n  \nFirst Stage High Pressure Turbine Disk AD/JT9D/30\n\n14th and 15th Stage HPC Disks AD/JT9D/31 Amdt 1\n\nCombustion Chamber Outer Casing AD/JT9D/32\n\nDiffuser Case Inspection AD/JT9D/33\n\nInspection of Critical Life-limited Rotating Engine Components - CANCELLED AD/JT9D/34\n\nHPT Disc Inspection AD/JT9D/35\n\nLPT 5th Stage Disc - Inspection AD/JT9D/36\n\nInspection of Life Limited Parts AD/JT9D/37\n\nHigh pressure Turbine Disc - Inspection AD/JT9D/38\n\nOne-Piece Fan Case Shield AD/JT9D/39","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument does not change the substantive obligations. It formally revokes and reissues the listed Airworthiness Directives in the same form as their latest published editions, preserving existing maintenance, inspection and replacement duties while altering only the administrative instrument form (see actions (a) and (b) and the accompanying note)."},"complexity_factors":["Delegated decision-making under subregulation 39.001(1) creates a single-authority administrative act rather than primary-legislation change (text: 'acting under subregulation 39.001 (1)').","Instrument performs two administrative steps: revoke and re-make each AD as separate instruments ((a) revoke; (b) make) which affects instrument formality and record-keeping.","Large list of individual ADs in Schedule 1 increases operational scope and administrative tracking needs (Schedule 1 lists many directives).","Some listed items are marked CANCELLED, requiring attention to which obligations persist (Schedule 1 shows cancelled AD/JT9D/1, AD/JT9D/2, AD/JT9D/34).","The instrument relies on external published editions of each AD — substantive content is preserved by reference to the latest published edition (note: 're-made in exactly the same form as appears in the latest published edition of the Directive').","Practical compliance burden is distributed to private operators and maintenance organisations who must perform inspections/modifications specified in the underlying ADs (implicit from AD types listed in Schedule 1).","Limited substantive rulemaking complexity — no new technical standards created here, but potential logistical complexity in implementing many existing ADs concurrently."],"plain_english_summary":"This instrument revokes a list of Airworthiness Directives for Pratt & Whitney JT9D engines and reissues each as a separate, identical instrument. It affects engine owners, airline operators and maintenance organisations required to carry out inspections, replacements and other mandated work. It matters because it preserves existing mandatory maintenance and compliance obligations (and their direct costs and operational constraints) while formalising issuance and enforcement actions under the CASA delegate (acting under subregulation 39.001(1))."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument explicitly states it remakes the directives 'in exactly the same form' as previously published. This is a pure administrative re-authorisation with no expansion of scope."},"complexity_factors":["Single, clear purpose: revoke and remake existing instruments","No conditional logic or nested exceptions in the instrument itself","Simple tabular structure listing 39 directives by name and number","Technical complexity exists in the *attached* ADs (not reproduced here), but the legislative instrument itself is straightforward","Only one defined term implicitly used ('Airworthiness Directive')","No cross-references to other legislation beyond the enabling regulation (Civil Aviation Safety Regulations 1998, subregulation 39.001(1))"],"plain_english_summary":"This instrument revokes and remakes 39 airworthiness directives for Pratt & Whitney JT9D engines (used on older large aircraft such as Boeing 747s), reissuing the same technical requirements in new legal form. The safety obligations—inspections, part replacements, life‑limit monitoring and related upgrades—remain unchanged.\n\nIt matters because ADs are legally binding on airlines, maintenance organisations and the manufacturer; this appears to be administrative housekeeping to ensure authorization and consistent legal formatting under current regulations."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-pratt-and-whitney-turbine-engines-jt9d-series","history":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-pratt-and-whitney-turbine-engines-jt9d-series/history","analysis":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-pratt-and-whitney-turbine-engines-jt9d-series/analysis","conflicts":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-pratt-and-whitney-turbine-engines-jt9d-series/conflicts","importantCases":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-pratt-and-whitney-turbine-engines-jt9d-series/important-cases","documents":"/api/acts/airworthiness-directives-2004-revocation-and-remaking-pratt-and-whitney-turbine-engines-jt9d-series/documents"}}