{"id":"F2006B07407","name":"AD/TFE 731/3 Amdt 1 - H.P. Turbine Blade P/N 3072111-1 - Replacement","slug":"ad-tfe-731-3-amdt-1-h-p-turbine-blade-p-n-3072111-1-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49631,"registerId":"commonwealth-F2006B07407-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TFE 731/3 Amdt 1 - H.P. Turbine Blade P/N 3072111-1 - Replacement","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  AlliedSignal (Garrett/AiResearch) Turbine Engines - TFE731 Series\n\n \n\nAD/TFE731/3\n\nAmdt 1\n\n\nH.P. Turbine Blade P/N 3072111-1 - Replacement 4/86\n\n \n\nApplicability: TFE 731-2-1C; -2-2B fitted with turbine blades P/N 3072111-1. Requirement:  Garrett S.B. TFE 731-72-3026 Rev 10.\n\nNote: Equipment modified I.A.W. a previous issue of this Directive may require further rework.\n\n \n\nCompliance: Before exceeding 1000 hours time in service.\n\n \n\nBackground:  This Directive is amended to reflect the manufacturers latest revision 10 to the Requirement Document which recommends no mixing of 3072455-10 blades with -9 or -12 and references S.B. TFE 731-72-3219 for turbine rotor assembly identification.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment updates the Requirement Document to Garrett S.B. TFE 731-72-3026 Rev 10 and explicitly adds a recommendation not to mix blade P/N 3072455-10 with -9 or -12, and it directs operators to S.B. TFE 731-72-3219 for turbine rotor assembly identification (Background).  It also records that equipment modified under a previous issue of this Directive may require further rework (Note).  These edits modify the operational scope by adding parts‑compatibility constraints and an additional identification reference, which can increase inspection and rework obligations for affected operators (Background; Note; Requirement)."},"complexity_factors":["Reference to a specific manufacturer Service Bulletin and its revision (Garrett S.B. TFE 731-72-3026 Rev 10) creates dependency on an external technical document for procedural detail (Requirement).","A short, mandatory compliance window (before exceeding 1,000 hours TIS) imposes scheduling and operational constraints on operators (Compliance).","Compatibility restriction (do not mix P/N 3072455-10 with -9 or -12) adds parts‑compatibility checks and potential additional replacements to achieve conformity (Background).","Cross‑reference to a second Service Bulletin for rotor assembly identification (S.B. TFE 731-72-3219) increases the number of technical identification steps required (Background).","Note that earlier modifications done under a prior issue may require further rework, creating potential retroactive obligations and variability in workload across operators (Note)."],"plain_english_summary":"What this instrument does (mechanics)\n\n- Requires replacement of high‑pressure turbine blades with part number 3072111-1 on specified Garrett/AiResearch TFE731 turbine engines (Applicability; Requirement).  Operators must carry out the replacement in accordance with Garrett Service Bulletin TFE 731-72-3026 Revision 10 (Requirement).\n- Sets a mandatory compliance time: the replacement must be done before the affected engine exceeds 1,000 hours time in service (Compliance).\n- Warns that units modified under an earlier version of this Directive may need additional rework to meet the updated requirement (Note).\n\nWho is affected\n\n- Aircraft operators and maintenance organisations that operate TFE 731-2-1C and TFE 731-2-2B engines fitted with turbine blades P/N 3072111-1 (Applicability).\n\nWhy it matters (stated purpose and operational implications)\n\n- The stated change is an amendment to reflect the manufacturer’s latest revision of the requirement document (Background).  That revision (Rev 10) includes a recommendation not to mix blade P/N 3072455-10 with P/N 3072455-9 or -12, and it points operators to Service Bulletin TFE 731-72-3219 for turbine rotor assembly identification (Background).\n\nCosts, who pays, and incentives\n\n- Aircraft operators and maintenance providers bear the direct costs: carrying out the blade replacements and any additional rework required by the updated Service Bulletin (Compliance; Note; Requirement).\n- Because the Directive references a specific manufacturer Service Bulletin (Requirement), compliance requires following that document’s procedures and parts guidance; operators have the incentive to identify affected parts and complete the replacement within the 1,000‑hour window to remain compliant (Requirement; Compliance).\n\nTrade-offs, implementation risk and compliance burden\n\n- The compliance burden is time‑bound and technical: replacing blades before 1,000 hours requires scheduling maintenance and possibly taking an aircraft out of service for the work (Compliance).\n- The amendment’s ban on mixing certain blade part numbers (3072455-10 with -9 or -12) and the cross‑reference to a rotor identification Service Bulletin introduce additional inspection and parts‑compatibility checks; that may increase inspection time, parts procurement needs, or require further rework where earlier modifications were made (Background; Note).\n- Implementation risk arises from correct identification of blade part numbers and rotor assembly condition per the referenced SBs; misidentification could lead to non‑compliance or the need for corrective actions (Background; Requirement).\n\nWho decides and discretion\n\n- The Civil Aviation Safety Authority (via this Airworthiness Directive) prescribes the mandatory action and the compliance time.  The technical steps and instructions to meet the Directive are delegated to the manufacturer’s Service Bulletin referenced in the Requirement (Requirement).\n\nConcrete behavioural changes required\n\n- Inspect engines for presence of blade P/N 3072111-1 (Applicability).\n- Replace those blades in accordance with Garrett S.B. TFE 731-72-3026 Rev 10 before the engine exceeds 1,000 hours (Requirement; Compliance).\n- Where prior work was done under an earlier issue of this Directive, perform any additional rework necessary to bring the equipment into conformity with the updated Requirement Document (Note).\n- For compatibility and assembly identification, follow the additional guidance in S.B. TFE 731-72-3219 as referenced (Background)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a minor amendment (Amendment 1) to an existing Airworthiness Directive. The amendment simply updates the referenced manufacturer document to its latest revision (Rev 10) and clarifies blade compatibility requirements. The core purpose — mandating replacement of specific turbine blades — remains unchanged from the original 1986 directive."},"complexity_factors":["Very short document (approximately 150 words)","Only 2 defined applicability criteria (engine models and part number)","Single compliance requirement with clear time limit","No nested exceptions or conditional logic","One cross-reference to manufacturer service bulletin","Minimal legislative machinery — operates as a direct regulatory instrument rather than complex enabling legislation"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires aircraft owners and operators to take specific action to fix a known safety problem.\n\n**What it does:**\nOrders the replacement of specific high-pressure (H.P.) turbine blades (part number 3072111-1) in certain AlliedSignal (Garrett/AiResearch) TFE731 series jet engines.\n\n**Who it affects:**\nOwners and operators of aircraft using TFE 731-2-1C or TFE 731-2-2B engines that have these specific turbine blades installed.\n\n**What must be done:**\nOperators must follow the manufacturer's Service Bulletin TFE 731-72-3026 (Revision 10) to replace the blades. This updated version clarifies that different blade types (-10, -9, and -12 variants) should not be mixed together, and points to another service bulletin for help identifying the correct turbine rotor assembly.\n\n**When it must be done:**\nBefore the affected engine parts accumulate more than 1,000 hours of flight time.\n\n**Why it matters:**\nTurbine blades operate under extreme heat and stress. Faulty or incompatible blades can fail catastrophically, causing engine failure and potentially endangering lives. This directive prevents that by ensuring problematic blades are replaced before they reach a critical wear threshold."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tfe-731-3-amdt-1-h-p-turbine-blade-p-n-3072111-1-replacement","history":"/api/acts/ad-tfe-731-3-amdt-1-h-p-turbine-blade-p-n-3072111-1-replacement/history","analysis":"/api/acts/ad-tfe-731-3-amdt-1-h-p-turbine-blade-p-n-3072111-1-replacement/analysis","conflicts":"/api/acts/ad-tfe-731-3-amdt-1-h-p-turbine-blade-p-n-3072111-1-replacement/conflicts","importantCases":"/api/acts/ad-tfe-731-3-amdt-1-h-p-turbine-blade-p-n-3072111-1-replacement/important-cases","documents":"/api/acts/ad-tfe-731-3-amdt-1-h-p-turbine-blade-p-n-3072111-1-replacement/documents"}}