{"id":"F2006B02559","name":"AD/ATF3/2 - Exhaust Splitter Seal Bolted Flange System","slug":"ad-atf3-2-exhaust-splitter-seal-bolted-flange-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41815,"registerId":"commonwealth-F2006B02559-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/ATF3/2 - Exhaust Splitter Seal Bolted Flange System","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nAlliedSignal (Garrett/AiResearch) Turbine Engines \\- ATF3 Series\n\nAD/ATF3/2 Exhaust Splitter Seal Bolted Flange System 8/86\n\nApplicability: ATF3-6-4C, \\-6A-3C and \\-6A-4C models with Part and Serial numbers as listed in the Requirement.\n\nRequirement: Install exhaust splitter seal bolted flange system in accordance with G.T.E.C. S.B. ATF3-72-6092 Rev. 2.\n\nNote: FAA AD T84-20-51 refers.\n\nCompliance: Unless already accomplished, at the next removal of H.P. turbine module but not later than 200 engine operating hours or 6 calendar months after 31 August 1986 whichever occurs first.\n\nBackground: An ATF3 engine has experienced an uncontained failure of the 6th stage L.P. turbine rotor blades as the result of detachment of the exhaust splitter seal from the exhaust liner.\n\nFAA AD T84-11-51 issued 25 May 1984 (superseded by FAA AD T84-20-51 October 84) instituted repetitive inspections of the stationary seal/6th stage L.P. turbine rotor for evidence of seal/rotor contact and/or looseness I.A.W. SBs A72-6090 and 6089; and the relevant engine L.M.M.s. These inspections are not necessary on engines which incorporate the splitter seal bolted flange system. This Directive is issued to prevent the possibility of an uncontained engine failure from this cause.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical failure mode in specific engine models. It has not expanded beyond its original purpose of mandating a hardware modification to prevent exhaust seal detachment."},"complexity_factors":["Single discrete technical requirement (install specific hardware per manufacturer bulletin)","Limited applicability (three specific engine models with enumerated part/serial numbers)","Clear compliance deadline with simple conditional logic (next maintenance event OR hard time limit, whichever first)","Cross-reference to one FAA AD and one manufacturer Service Bulletin","No nested exceptions or complex defined terms","Background explanation provided in plain language"],"plain_english_summary":"This AD mandates owners/operators and maintenance organizations of certain AlliedSignal (Garrett/AiResearch) ATF3-6-4C, -6A-3C, and -6A-4C engines install a redesigned exhaust splitter seal bolted flange per Service Bulletin ATF3-72-6092 Rev. 2 to prevent catastrophic uncontained failures caused by a loose exhaust seal.\n\nCompliance is required at the next high‑pressure turbine removal or within 200 flight hours or six months after 31 Aug 1986, whichever occurs first."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Yes. The Directive replaces the earlier inspection regime (Background, referencing FAA AD T84‑20‑51) with a mandatory installation of the bolted flange system (Requirement). That changes compliance from periodic inspections to a one‑off modification: operators incur upfront parts, labour and downtime costs, but no longer need the repetitive inspections once the modification is installed (Background; Compliance)."},"complexity_factors":["Technical retrofit mandated to a specific service bulletin (Requirement: G.T.E.C. S.B. ATF3‑72‑6092 Rev.2) — requires parts, qualified labour and shop time.","Applicability limited to particular ATF3‑6‑4C, ‑6A‑3C and ‑6A‑4C models with listed part and serial numbers (Applicability) — necessitates record checks.","Compliance timing tied to next H.P. turbine module removal or a short hours/calendar deadline (Compliance) — creates scheduling and operational pressure.","Change from recurring inspections to a terminating modification (Background referencing FAA AD T84‑20‑51) — shifts ongoing inspection costs into a one‑off retrofit cost.","Safety consequence motivating the AD is risk of uncontained L.P. rotor failure from seal detachment (Background) — enforcement and safety oversight by CASA.","Implementation risks include parts availability and access to maintenance facilities capable of the installation."],"plain_english_summary":"This Airworthiness Directive requires operators of specified AlliedSignal ATF3 engines to install an exhaust splitter seal bolted‑flange system per G.T.E.C. S.B. ATF3‑72‑6092 Rev.2. It applies to engines listed in the Directive and must be done at the next H.P. turbine module removal or within 200 engine‑hours or six months after 31 August 1986. The AD substitutes the earlier repetitive inspections with a modification; operators bear parts, installation and downtime costs but avoid recurring inspections."}},"importantCases":[],"_links":{"self":"/api/acts/ad-atf3-2-exhaust-splitter-seal-bolted-flange-system","history":"/api/acts/ad-atf3-2-exhaust-splitter-seal-bolted-flange-system/history","analysis":"/api/acts/ad-atf3-2-exhaust-splitter-seal-bolted-flange-system/analysis","conflicts":"/api/acts/ad-atf3-2-exhaust-splitter-seal-bolted-flange-system/conflicts","importantCases":"/api/acts/ad-atf3-2-exhaust-splitter-seal-bolted-flange-system/important-cases","documents":"/api/acts/ad-atf3-2-exhaust-splitter-seal-bolted-flange-system/documents"}}