{"id":"F2009L03256","name":"AD/TPE 331/64 - First Stage Turbine Disc","slug":"ad-tpe-331-64-first-stage-turbine-disc","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":140663,"registerId":"commonwealth-F2009L03256-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AlliedSignal (Garrett/AiResearch) Turbin","sectionType":"division","heading":"AlliedSignal (Garrett/AiResearch) Turbine Engines - TPE 331 Series","content":"### AlliedSignal (Garrett/AiResearch) Turbine Engines - TPE 331 Series\n\n| AD/TPE 331/64 | First Stage Turbine Disc | 11/2009 DM |\n| ------------- | ------------------------ | ---------- |\n\n| Applicability: | Honeywell International Inc. TPE331-10 and TPE331-11 series turboprop engines with a first stage turbine disk, P/N 3101520-1 or 3107079-1, serial number2-03501-2299, 2-03501-2300, 2-03501-2301, 2-03501-2302, or 2-03501-2304 installed.Note 1: These engines are installed on, but not limited to, the following aeroplanes: British Aerospace Jetstream 3201 series, Cessna Aircraft Company Model 441 Conquest, Construcciones Aeronauticas, S.A. (CASA) C-212 series, Dornier Luftfahrt Dornier 228 series, Hawker Beechcraft (formerly Raytheon, formerly Beech) B100, C90 and E90, M7 Aerospace (formerly Fairchild) SA226 and SA227 series (Swearingen Merlin and Metro series), Mitsubishi MU-2B series (MU-2 series),PZL M18 series and Twin Commander 680 and 690 series (Jetprop Commander). |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Remove from service first stage turbine disks, P/N 3101520-1 and P/N3107079-1, serial numbers 2-03501-2299, 2-03501-2300, 2-03501-2301,2-03501-2302, and 2-03501-2304.2. Do not install first stage turbine disks, P/N 3101520-1 and P/N 3107079-1, serial numbers 2-03501-2299, 2-03501-2300, 2-03501-2301, 2-03501-2302, and2-03501-2304, into any engine.Note 2: FAA AD 2009-17-05 Amdt 39-15996 dated 11 August 2009 refers.                                                                                                                                                                                                                                                                                                                                                                       |\n| Compliance:    | For Requirement 1 - Within 25 flight hours or 25 cycles-in-service after the effective date of this AD, whichever occurs first.For Requirement 2 - After the effective date of this AD.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n|                | This Airworthiness Directive becomes effective on 1 September 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |\n\n| Background: | This AD results from a report of an uncontained failure of a first stage turbine disk that had a metallurgical defect. This AD is intended to prevent uncontained failure of the first stage turbine disk and damage to the aeroplane. |\n| ----------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n18 August 2009","sortOrder":0},{"sectionNumber":"AD/TPE 331/64","sectionType":"part","heading":"AD/TPE 331/64","content":"## AD/TPE 331/64","sortOrder":1},{"sectionNumber":"First Stage Turbine Disc","sectionType":"part","heading":"First Stage Turbine Disc","content":"## First Stage Turbine Disc","sortOrder":2},{"sectionNumber":"11/2009 DM","sectionType":"part","heading":"11/2009 DM","content":"## 11/2009 DM","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive's scope is limited to the listed first-stage turbine disc part numbers and serial numbers installed in TPE331-10 and -11 engines. This matches the stated safety purpose (prevent uncontained failure due to a reported metallurgical defect) and does not expand or narrow the field of affected parts or engines beyond the document's explicit applicability."},"complexity_factors":["Narrow technical scope: specific part numbers and six discrete serial numbers reduces interpretive ambiguity.","Safety-critical nature increases operational urgency despite straightforward remedy (remove and prohibit reinstall).","Short compliance window (25 flight hours or 25 cycles) increases scheduling and downtime pressure for operators.","Applicability across multiple aircraft types requires coordination by diverse operators and maintenance organisations.","Cross-reference to FAA AD introduces inter-jurisdictional conformity and reliance on external certification/documentation.","Enforcement depends on accurate maintenance records and parts traceability, creating administrative compliance burden."],"plain_english_summary":"This Airworthiness Directive requires operators to remove specific first-stage turbine discs (P/N 3101520-1 and 3107079-1) with listed serial numbers and forbids reinstalling them. It applies to Honeywell TPE331-10 and TPE331-11 engines fitted to various turboprop aircraft. \n\nA reported metallurgical defect prompted the measure to prevent uncontained disc failure. Operators must replace affected discs within 25 flight hours or 25 cycles; operators bear replacement and downtime costs, and the regulator enforces compliance (Requirement; Compliance)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific metallurgical defect in specific serial-numbered turbine discs. It has not expanded beyond its original safety purpose of preventing uncontained engine failures."},"complexity_factors":["Single, specific mechanical defect addressed with clear part numbers and serial numbers","Only two straightforward requirements: remove existing parts and prohibit future installation","Simple compliance timeline: 25 flight hours/cycles for removal, immediate prohibition on installation","No nested exceptions, conditional logic, or cross-references to other legislation beyond a single reference to the corresponding FAA directive","Limited applicability: only 5 specific serial numbers of 2 part numbers across 2 engine series","No defined terms section or interpretive provisions"],"plain_english_summary":"This CASA Airworthiness Directive requires immediate removal and permanent prohibition of specific turbine discs (Honeywell TPE331‑10/11, certain P/Ns/S/Ns) from affected turboprop engines, with removal within 25 flight hours or 25 engine cycles after 1 September 2009. It affects aircraft operators and maintenance organisations of numerous types (e.g., Jetstream, Cessna Conquest, Dornier 228, Mitsubishi MU‑2, Twin Commander, etc.). The AD prevents catastrophic uncontained disc failure that could injure occupants or destroy an aircraft."},"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/ad-tpe-331-64-first-stage-turbine-disc","history":"/api/acts/ad-tpe-331-64-first-stage-turbine-disc/history","analysis":"/api/acts/ad-tpe-331-64-first-stage-turbine-disc/analysis","conflicts":"/api/acts/ad-tpe-331-64-first-stage-turbine-disc/conflicts","importantCases":"/api/acts/ad-tpe-331-64-first-stage-turbine-disc/important-cases","documents":"/api/acts/ad-tpe-331-64-first-stage-turbine-disc/documents"}}