{"id":"F2005L02047","name":"AD/TFE 731/34 - 1st and 2nd Stage Low Pressure Turbine Rotor Discs","slug":"ad-tfe-731-34-1st-and-2nd-stage-low-pressure-turbine-rotor-discs","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":36211,"registerId":"commonwealth-F2005L02047-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AlliedSignal (Garrett/AiResearch) Turbin","sectionType":"division","heading":"AlliedSignal (Garrett/AiResearch) Turbine Engines - TFE731 Series","content":"### AlliedSignal (Garrett/AiResearch) Turbine Engines - TFE731 Series\n\n| AD/TFE 731/34 | 1st and 2nd Stage LowPressure Turbine Rotor Discs | 9/2005 |\n| ------------- | ------------------------------------------------- | ------ |\n\n```html\n

Applicability:

Honeywell International Inc. (formerly AlliedSignal Inc. and Garrett Turbine Engine Co.) TFE731-2 and -3 series turbofan engines with the following low pressure (LP) 1st and 2nd stage turbine rotor disc part numbers (P/Ns), with serial numbers (SNs) listed in Tables 1, 2, and 3 of Honeywell International Inc. SB No. TFE731-72-3682, dated 26 November 2002, initially installed as new parts before 1 April 1991:

Part Numbers

3072069-All

3073014-All

3072070-All

3073113-All

3072351-All

3071114-All

3072542-All

3074103-All

3073013-All

3074105-All

(All denotes all dash numbers installed)

Note 1: These engines are installed on, but not limited to, the following aeroplanes:

Avions Marcel Dassault Mystere-Falcon 10 and 50 series

Cessna Model 650, Citation III, and Citation VI

Gulfstream Aerospace LP (formerly IAI) 1125 Westwind Astra series

Israel Aircraft Industries (IAI) 1124 series

Learjet 31, 35, 36, and 55 series

Lockheed-Georgia 1329-25 series (731 Jetstar, Jetstar II)

Raytheon Corporate Jets (formerly British Aerospace) DH/HS/BH-125 series;

Sabreliner NA-265-65 (Sabreliner 65)

\n```\n\n| Requirement: | 1. For TFE731-2-2J, TFE731-2-2N, TFE731-2A-2A, and TFE731-3-1J engines, replace discs that are listed by SN in Tables 1 and 3 of SB No. TFE731-72-3682.2. For TFE731-2 series engines except TFE731-2-2J, TFE731-2-2N, and TFE731-2A-2A engines, replace discs that are listed by SN in Tables 1 and 2 of SB No. TFE731-72-3682.3. For TFE731-3 series engines except TFE731-3-1J, replace discs that are listed by SN in Table 3 of SB No. TFE731-72-3682.4. Do not install any LP 1st and 2nd stage turbine rotor disc that has a SN listed in Table 1, 2, or 3 of SB No. TFE731-72-3682 and determined to be manufactured before 1 April 1991.Definition: For the purposes of this AD, access to the turbine discs is the level of disassembly that has removed the tie-shaft nut.Note 2: FAA AD 2005-13-07 Amendment 39-14143 refers. |\n| ------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Compliance: | 1. Within 100 hours time- in-service (TIS) after the effective date of this Directive.2. At the next Major Periodic Inspection (MPI) or next access to the turbine discs after the effective date of this Directive, but within 2,200 hours TIS since the last disc inspection, whichever occurs first.3. At the next MPI or next access to the turbine discs after the effective date of this Directive, but within 1,500 hours TIS since the last disc inspection, whichever occurs first.4. After the effective date of this Directive. |\n| | This Airworthiness Directive becomes effective on 1 September 2005. |\n| Background: | This Directive results from a report of an uncontained failure of an LP 2nd stage turbine rotor disc that resulted in an in-flight engine shutdown. This Directive is intended to prevent LP turbine rotor disk separation, which could result in an uncontained engine failure and damage to the aeroplane. |\n\n![](image.001.png) \nDavid Villiers \nDelegate of the Civil Aviation Safety Authority\n\n22 July 2005","sortOrder":0},{"sectionNumber":"AD/TFE 731/34","sectionType":"part","heading":"AD/TFE 731/34","content":"## AD/TFE 731/34","sortOrder":1},{"sectionNumber":"1st","sectionType":"part","heading":"and 2nd Stage LowPressure Turbine Rotor Discs","content":"## 1st and 2nd Stage Low \nPressure Turbine Rotor Discs","sortOrder":2},{"sectionNumber":"9/2005","sectionType":"part","heading":"9/2005","content":"## 9/2005","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"Scope aligns with the Directive's stated purpose: remove specific LP rotor discs listed by serial number and manufactured before 1 April 1991 to prevent uncontained failures. The Directive targets identified engine models/serials, prohibits reinstallation of listed discs, and sets model‑dependent compliance windows; it does not expand beyond those engines, serial ranges, or the stated accessory definition (Applicability; Requirement; Definition; Compliance)."},"complexity_factors":["SN‑specific applicability requiring cross-check of serial numbers in three external SB tables (Applicability; Requirement)","Multiple engine variants with different lists and exclusions (Requirement)","Staggered compliance deadlines: immediate short window (100 hours TIS) and longer MPI/access-based windows (100h, next MPI or access within 1,500–2,200 hours TIS) (Compliance)","Prohibition on reinstalling listed discs once identified (Requirement)","Dependency on external manufacturer service bulletin for identification and FAA AD cross-reference (Note 1; Note 2; Requirement)","Technical access threshold defined (tie‑shaft nut removed) affecting maintenance effort and cost (Definition)","Operational disruption risk from required disc replacement during next MPI or access (Compliance)","Recordkeeping and parts-tracking burdens for operators and maintenance organisations (implicit in Applicability/Requirement)","Potential supply/logistics constraints if many discs must be replaced within short windows (Compliance/Background)"],"plain_english_summary":"This Directive requires owners/operators of Honeywell (formerly AlliedSignal/Garrett) TFE731-2 and -3 series engines to remove and not reinstall certain low-pressure 1st and 2nd stage turbine rotor discs if their serial numbers appear in Tables 1–3 of Honeywell SB No. TFE731-72-3682 and were manufactured before 1 April 1991. Compliance deadlines vary by engine model and inspection/access timing. The measure responds to a reported uncontained LP disc failure and aims to reduce risk of in‑flight engine failure and aircraft damage."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific metallurgical defect in pre-1991 turbine discs. It does not expand beyond the original safety-critical purpose of preventing catastrophic disc failure."},"complexity_factors":["Multiple engine sub-models with different compliance paths (TFE731-2-2J/2N/2A-2A vs other -2 series vs -3 series)","Cross-reference to external Honeywell Service Bulletin (SB TFE731-72-3682) containing serial number tables not reproduced in the AD","Three different compliance timeframes depending on engine model and maintenance history","Technical aviation terminology requiring specialised knowledge (TIS = Time-In-Service, MPI = Major Periodic Inspection)","Nested applicability criteria: part numbers, serial numbers, manufacture dates, and installation dates"],"plain_english_summary":"This AD mandates replacement of certain Honeywell TFE731‑2 and TFE731‑3 low‑pressure turbine rotor discs (pre‑April‑1991 production) shown by Honeywell Service Bulletin TFE731‑72‑3682 to risk cracking and catastrophic failure. It affects operators of business jets (Learjet, Falcon, Citation, etc.) and requires replacement within 100 flight hours or by the next major inspection/maintenance window (or by specified flight‑hour limits) to prevent uncontained engine failures."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tfe-731-34-1st-and-2nd-stage-low-pressure-turbine-rotor-discs","history":"/api/acts/ad-tfe-731-34-1st-and-2nd-stage-low-pressure-turbine-rotor-discs/history","analysis":"/api/acts/ad-tfe-731-34-1st-and-2nd-stage-low-pressure-turbine-rotor-discs/analysis","conflicts":"/api/acts/ad-tfe-731-34-1st-and-2nd-stage-low-pressure-turbine-rotor-discs/conflicts","importantCases":"/api/acts/ad-tfe-731-34-1st-and-2nd-stage-low-pressure-turbine-rotor-discs/important-cases","documents":"/api/acts/ad-tfe-731-34-1st-and-2nd-stage-low-pressure-turbine-rotor-discs/documents"}}