{"id":"F2006B11184","name":"AD/LTS/7 Amdt 2 - Power Turbine Rotor","slug":"ad-lts-7-amdt-2-power-turbine-rotor","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56886,"registerId":"commonwealth-F2006B11184-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/LTS/7 Amdt 2 - Power Turbine Rotor","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 (Lycoming) Turbine Engines \\- LTS 101 Series\n\nAD/LTS/7\n\nAmdt 2\n\n  \nPower Turbine Rotor 3/91\n\nApplicability: All LTS 101 series engines fitted with Power Turbine Rotors part number 4-141-070- XX.\n\nRequirement: Action in accordance with Textron Lycoming SB No LT 101-72-00-0093 Rev. 5\n\nNote: FAA AD 87-11-09 refers.\n\nCompliance: Unless previously accomplished; within 50 hours time in service from 21 March 1991, and thereafter at intervals not to exceed 50 hours or 300 cycles, whichever occurs first.\n\nBackground: This Directive has been amended to reflect the manufacturers latest revision to the Requirement Document detailed in FAA AD 87-11-09. This amendment also reflects the release of an individually bladed power turbine rotor. LTS101 series engines fitted with individually bladed power turbine rotors are not affected by this Directive.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment updates the requirement document reference to the manufacturer's latest revision and narrows the Directive's applicability by excluding engines fitted with the newly released individually bladed power turbine rotor. The Directive therefore changed scope relative to earlier versions by expressly removing engines with individually bladed rotors from its coverage and by tying required action to the updated Textron Lycoming service bulletin. (Background, Requirement, Applicability)"},"complexity_factors":["Narrow technical applicability tied to a specific part number (4-141-070-XX). (Applicability)","Mandates compliance with an external manufacturer service bulletin (Textron Lycoming SB No LT 101-72-00-0093 Rev. 5), requiring users to obtain and follow that document. (Requirement)","Recurring inspection schedule with dual criteria (every 50 hours or 300 cycles, whichever occurs first), adding operational scheduling complexity. (Compliance)","Amendment excludes a specific rotor type (individually bladed rotors), creating differential treatment between otherwise similar engines. (Background)","Cross-reference to FAA AD introduces external regulatory alignment considerations. (Note)"],"plain_english_summary":"This Directive requires operators of Lycoming LTS101 turbine engines fitted with power turbine rotors part number 4-141-070-XX to carry out the maintenance in Textron Lycoming Service Bulletin LT 101-72-00-0093 Rev. 5, initially within 50 flight hours from 21 March 1991 and then every 50 hours or 300 cycles.\n\nIt directly affects operators and maintenance organisations (who bear cost and downtime), limits discretion by mandating the manufacturer’s procedure, and explicitly excludes engines with individually bladed power turbine rotors."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment remains tightly scoped to its original purpose: ensuring safety of specific power turbine rotors in LTS 101 engines. The amendment narrows scope slightly by explicitly excluding individually bladed rotors, but this is a refinement rather than scope creep."},"complexity_factors":["Single, specific technical requirement referencing an external manufacturer service bulletin","Only one defined applicability criterion (part number prefix)","Simple compliance structure: initial deadline + recurring interval with clear 'whichever occurs first' logic","One explicit exemption (individually bladed rotors)","No nested definitions, cross-references to other legislation, or conditional exceptions","Total length: approximately 150 words of substantive content"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). Think of it like a compulsory recall notice, but for aircraft engines rather than cars.\n\n**What it does:** It requires owners and operators of specific AlliedSignal (Lycoming) LTS 101 series turbine engines to inspect their \"Power Turbine Rotor\" — a critical spinning component that extracts energy from hot gases to produce power. The inspection must follow a specific manufacturer service bulletin (SB No LT 101-72-00-0093 Rev. 5).\n\n**Who it affects:** Anyone operating aircraft with LTS 101 series engines that have Power Turbine Rotors with part numbers starting with \"4-141-070-\". **Important exemption:** Engines with newer \"individually bladed\" power turbine rotors are **not** affected by this directive.\n\n**What must be done:**\n- **First inspection:** Within 50 hours of flying time after 21 March 1991\n- **Repeat inspections:** Every 50 flight hours **or** every 300 engine cycles (whichever comes first)\n- **Unless already done:** If the work was already completed before this directive, you're covered\n\n**Why it matters:** Power turbine rotors spin at extremely high speeds. If they fail, the engine loses power and could cause catastrophic damage. This directive prevents failures by mandating regular inspections based on the manufacturer's updated safety recommendations and a corresponding US Federal Aviation Administration (FAA) directive (AD 87-11-09).\n\n**Key update in this version (Amendment 2):** The directive was updated to match the manufacturer's latest guidance and to clarify that modern individually bladed rotors don't need these inspections."}},"importantCases":[],"_links":{"self":"/api/acts/ad-lts-7-amdt-2-power-turbine-rotor","history":"/api/acts/ad-lts-7-amdt-2-power-turbine-rotor/history","analysis":"/api/acts/ad-lts-7-amdt-2-power-turbine-rotor/analysis","conflicts":"/api/acts/ad-lts-7-amdt-2-power-turbine-rotor/conflicts","importantCases":"/api/acts/ad-lts-7-amdt-2-power-turbine-rotor/important-cases","documents":"/api/acts/ad-lts-7-amdt-2-power-turbine-rotor/documents"}}