{"id":"F2006B07396","name":"AD/TFE 731/13 - Turbine Interstage Transition Duct Re-Inspection","slug":"ad-tfe-731-13-turbine-interstage-transition-duct-re-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49594,"registerId":"commonwealth-F2006B07396-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TFE 731/13 - Turbine Interstage Transition Duct Re-Inspection","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/TFE731/13 Turbine Interstage Transition Duct Re-Inspection 6/86\n\nApplicability: TPE 731-2, \\-3, \\-3A, \\-3AR, \\-3B, \\-3BR, \\-3R engines.\n\nRequirement: In accordance with requirements of FAA AD 86-03-01 Amdt 39-5212.\n\nReference Documents:\n\nFAA AD 86-03-01 Amdt 39-5212 Garrett SB TFE 731-72-3309 R1 Garrett SB TFE 731-72-3159 R5\n\nCompliance: At next major periodic inspection or at next access of affected part, whichever occurs first after 30 June 1986.\n\nBackground: This Directive has been issued to require re-inspection of certain turbine interstage transition ducts which were previously inspected by compliance with Garrett SB TFE731-72-3159 (AD/TFE731/7).\n\nThe ducts, listed by serial number in Garrett SB TFE 731-72-3309 R1, are considered suspect following advice of an error in the inspection procedure carried out on the affected ducts during compliance with Garrett SB TFE 731-72-3159 (AD/TFE731/7).","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a targeted, time-bound safety directive addressing a specific manufacturing/inspection error. It has not expanded beyond its original purpose of ensuring proper re-inspection of suspect turbine ducts."},"complexity_factors":["Short, single-purpose directive (approximately 200 words)","Only 7 engine variants listed in applicability","Simple conditional compliance trigger (next inspection OR next access, whichever first)","Heavy reliance on external reference documents (3 referenced FAA/Garrett documents)","No defined terms section — uses industry-standard aviation terminology","Single background narrative explaining the safety rationale"],"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 safety problem.\n\n**What it does:**\nOrders re-inspection of a specific engine part — the \"turbine interstage transition duct\" — on certain AlliedSignal (formerly Garrett/AiResearch) TFE731 jet engines.\n\n**Why it matters:**\nSome of these ducts were previously inspected following an earlier safety bulletin, but the original inspection procedure contained an **error**. This means some faulty parts may have been missed. This directive catches those potentially dangerous parts before they fail.\n\n**Who must comply:**\nAnyone operating aircraft with these specific engine models: TFE731-2, -3, -3A, -3AR, -3B, -3BR, and -3R variants.\n\n**What must be done:**\nOperators must re-inspect the affected ducts (identified by serial number in a specific service bulletin) at either:\n- Their next major periodic inspection, **or**\n- The next time they access the affected part\n\nWhichever comes first after 30 June 1986.\n\n**Key point:** This directive doesn't create new inspection rules from scratch — it simply adopts the American Federal Aviation Administration's (FAA) safety order (AD 86-03-01) and applies it to Australian-registered aircraft."},"summary":{"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This airworthiness directive imposes a re-inspection requirement for certain turbine interstage transition ducts on TFE731 series engines to correct a previous inspection deficiency."},"complexity_factors":["Narrow application to specific engine models and individual duct serial numbers","Clear compliance deadline based on scheduled maintenance events","Straightforward re-inspection triggered by a known earlier inspection error"],"plain_english_summary":"This AD requires re‑inspection of specific turbine interstage transition ducts on AlliedSignal TFE731‑2/‑3/‑3A/‑3AR/‑3B/‑3BR/‑3R engines because an earlier inspection used the wrong procedure, leaving those ducts suspect (serial numbers listed in Garrett SB TFE 731‑72‑3309 R1). Operators must re‑inspect per FAA AD 86‑03‑01 at the next major inspection or next access after 30 June 1986. No design changes or life limits are introduced—this corrects a prior inspection error to ensure airworthiness."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This directive alters the earlier inspection regime by imposing a mandatory re‑inspection requirement for a defined list of ducts previously inspected under AD/TFE731/7; it narrows enforcement to serial‑numbered parts identified in Garrett SB TFE 731-72-3309 R1 and sets a specific compliance trigger (Background; Requirement; Compliance)."},"complexity_factors":["Narrow, part‑specific applicability — applies only to TFE731-2, -3, -3A, -3AR, -3B, -3BR, -3R engines and ducts listed by serial number (Applicability; Background).","Dependency on external documents for procedure — compliance is \"in accordance with requirements of FAA AD 86-03-01 Amdt 39-5212\" and references Garrett service bulletins for inspection method and serial numbers (Requirement; Reference Documents).","Timing trigger tied to maintenance events — compliance required at next major periodic inspection or next access of the affected part after 30 June 1986, which creates operational scheduling and access-cost implications for operators (Compliance).","Corrective, not general, scope — targets ducts previously inspected under Garrett SB TFE731-72-3159 (AD/TFE731/7) because of an identified inspection error, so it creates a rework obligation for a defined subset of parts (Background).","Limited procedural detail in the AD itself — the directive defers to FAA AD and manufacturer bulletins for inspection technique, leaving operators reliant on those external sources for technical steps (Requirement; Reference Documents).","Compliance burden concentrated and identifiable — costs and labour fall on aircraft/engine owners and maintenance organisations when accessing and re‑inspecting the listed ducts (Compliance)."],"plain_english_summary":"This airworthiness directive requires owners/operators of AlliedSignal TFE731 series engines to re‑inspect specific turbine interstage transition ducts listed by serial number in a Garrett service bulletin. The re‑inspection must be done at the next major periodic inspection or the next time the part is accessed after 30 June 1986. It responds to an identified error in the earlier inspection procedure and is intended to confirm the continued airworthiness of those listed parts."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tfe-731-13-turbine-interstage-transition-duct-re-inspection","history":"/api/acts/ad-tfe-731-13-turbine-interstage-transition-duct-re-inspection/history","analysis":"/api/acts/ad-tfe-731-13-turbine-interstage-transition-duct-re-inspection/analysis","conflicts":"/api/acts/ad-tfe-731-13-turbine-interstage-transition-duct-re-inspection/conflicts","importantCases":"/api/acts/ad-tfe-731-13-turbine-interstage-transition-duct-re-inspection/important-cases","documents":"/api/acts/ad-tfe-731-13-turbine-interstage-transition-duct-re-inspection/documents"}}