{"id":"F2006B07399","name":"AD/TFE 731/16 - HP Turbine Rotor Disc P/N 3072316-2/-3 and P/N 3073110-1/-2","slug":"ad-tfe-731-16-hp-turbine-rotor-disc-p-n-3072316-2-3-and-p-n-3073110-1-2","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49604,"registerId":"commonwealth-F2006B07399-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TFE 731/16 - HP Turbine Rotor Disc P/N 3072316-2/-3 and P/N 3073110-1/-2","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 \\- TFE731 Series\n\nAD/TFE731/16 HP Turbine Rotor Disc P/N 3072316-2/-3\n\nand P/N 3073110-1/-2\n\n  \n5/89 DM\n\nApplicability: TFE 731-3 series engines fitted with HP turbine rotor disc whose serial numbers are listed in the Requirement Document.\n\nRequirement: Remove from service and inspect specific serial numbered HP turbine rotor disc P/N 3072316-2/-3 and P/N 3073110-1/-2 in accordance with Allied Signal Aerospace (Garrett) Service Bulletin TFE 731-A72-3388.\n\nCompliance: Prior to achieving 150 operating cycles after 29 March 1989.\n\nBackground: A recent engine inflight shutdown was caused by the uncontained separation of an HP turbine rotor disc. Investigation determined that disc fracture occurred due to low cycle fatigue from an inclusion of foreign material within the disc.\n\nThis Directive is issued to remove from service and inspect suspect HP turbine discs.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific mechanical failure mode in specific engine serial numbers. It has not expanded beyond its original purpose of grounding and inspecting suspect turbine discs."},"complexity_factors":["Single, specific mechanical part targeted (HP turbine rotor disc)","Only two part numbers affected (P/N 3072316-2/-3 and P/N 3073110-1/-2)","One clear compliance action: remove and inspect per referenced Service Bulletin","Simple deadline structure: 150 operating cycles after fixed date","No nested exceptions, conditional logic, or extensive defined terms","Background explanation included in plain language"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific aircraft engines to be inspected or repaired.\n\n**What it does:**\nOrders owners and operators of certain **AlliedSignal (Garrett/AiResearch) TFE731-3 series turbine engines** to remove and inspect a specific high-pressure turbine rotor disc part. The affected parts have serial numbers listed in a separate technical document (Service Bulletin TFE 731-A72-3388).\n\n**Why it matters:**\nA turbine rotor disc broke apart during flight, causing an engine shutdown. The disc failed because foreign material got inside the metal during manufacturing, creating a weakness that led to cracking from repeated heating and cooling cycles (called \"low cycle fatigue\"). This directive prevents similar dangerous failures by catching defective discs before they break.\n\n**Who must comply:**\nAnyone operating aircraft with these specific engines and the listed rotor disc serial numbers.\n\n**Deadline:**\nBefore the engine completes 150 operating cycles after 29 March 1989."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive implements a targeted safety action as described: it applies to TFE731-3 series engines fitted with HP turbine rotor discs whose serial numbers are listed in the Requirement Document and mandates removal and inspection per the manufacturer’s service bulletin, with a specified compliance window (Applicability; Requirement; Compliance). The text does not indicate any expansion or narrowing of scope beyond this stated requirement."},"complexity_factors":["Technical specificity: requirement targets specific HP turbine rotor discs by part number and serial numbers (Applicability).","Cross-reference to manufacturer procedure: mandated inspections must follow AlliedSignal Service Bulletin TFE 731-A72-3388 (Requirement).","Short, fixed compliance window: inspections due before 150 operating cycles after 29 March 1989 creates scheduling urgency (Compliance).","Safety-critical consequences: inspection and removal actions relate to uncontained rotor failure, raising stakes for correct implementation (Background).","Record-dependence: operators must check serial-number records to determine applicability, creating administrative burden (Applicability).","Potential for follow-on maintenance/replacement costs if defects are found (Requirement)."],"plain_english_summary":"This directive requires operators of certain TFE731-3 engines to remove specific high‑pressure turbine rotor discs (only those serial‑numbered in the Requirement Document) from service and inspect them per AlliedSignal Service Bulletin TFE 731‑A72‑3388. It was issued after an inflight shutdown caused by a disc fracture from a foreign‑material inclusion; the goal is to detect and fix similarly affected discs before failure. Operators bear inspection, repair/replacement costs, downtime, and must meet the 150‑cycle compliance deadline."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tfe-731-16-hp-turbine-rotor-disc-p-n-3072316-2-3-and-p-n-3073110-1-2","history":"/api/acts/ad-tfe-731-16-hp-turbine-rotor-disc-p-n-3072316-2-3-and-p-n-3073110-1-2/history","analysis":"/api/acts/ad-tfe-731-16-hp-turbine-rotor-disc-p-n-3072316-2-3-and-p-n-3073110-1-2/analysis","conflicts":"/api/acts/ad-tfe-731-16-hp-turbine-rotor-disc-p-n-3072316-2-3-and-p-n-3073110-1-2/conflicts","importantCases":"/api/acts/ad-tfe-731-16-hp-turbine-rotor-disc-p-n-3072316-2-3-and-p-n-3073110-1-2/important-cases","documents":"/api/acts/ad-tfe-731-16-hp-turbine-rotor-disc-p-n-3072316-2-3-and-p-n-3073110-1-2/documents"}}