{"id":"F2006B02314","name":"AD/ALF/18 - Turbine Component Life Limits","slug":"ad-alf-18-turbine-component-life-limits","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41544,"registerId":"commonwealth-F2006B02314-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\nAllied Signal (Lycoming) Turbine Engines \\- ALF502 and LF507 Series","sortOrder":0},{"sectionNumber":"AD/ALF/18 Turbine Component Life Limits ","sectionType":"part","heading":"AD/ALF/18 Turbine Component Life Limits 9/2002","content":"# AD/ALF/18 Turbine Component Life Limits 9/2002\n\nApplicability: Honeywell ALF502 and LF507 Series engines identified in the requirement document.\n\nRequirement: Remove from service, First Rotor Sealing Plates, First Turbine Rotor Disc and Turbine Spacer per the requirements of FAA AD 2002-12-08.\n\nNote: FAA AD 2002-12-08, Amdt 39-12780 refers.\n\nCompliance: As detailed in the requirement document with a revised effective date of 5 September 2002.\n\nThis Airworthiness Directive becomes effective on 5 September 2002.\n\nBackground: On-going analysis of field returned hardware has indicated that the low cycle fatigue limits of the turbine hardware are lower than that estimated initially. Hence a lower life limit and a draw down schedule are mandated per this Directive for some turbine hardware.\n\n![](image.002.png)  \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 29 July 2002\n\n![](image.001.png)","sortOrder":1}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"The Directive reduces the approved life limits for certain turbine components and imposes a draw‑down schedule where initial life estimates were higher. The change is operationally material: it narrows remaining service life for affected parts and compels earlier removal/replacement than under the original estimates (Background; Requirement)."},"complexity_factors":["Technical content: requires understanding of low‑cycle fatigue and life‑limit calculation for turbine components (Background).","Cross‑reference to external instrument: compliance is tied to FAA AD 2002‑12‑08, adding dependency on another regulator's document (Requirement).","Operational burden: mandates removal and replacement of specific parts, imposing direct maintenance, inventory and downtime costs on operators (Requirement; Compliance).","Tracking and scheduling: introduces a draw‑down schedule and revised life limits requiring record‑keeping and fleet management adjustments (Requirement; Compliance).","Regulatory discretion: issued under CAR 1998 subreg 39.1(1) by a CASA delegate, concentrating decision authority in the regulator's delegated action (preamble/first paragraph).","Narrow applicability: applies only to ALF502 and LF507 engines identified in the requirement document, limiting scope but concentrating effect on affected operators (Applicability).","Effective date revision: revised effective date (5 September 2002) creates a fixed compliance timeline that operators must meet (Compliance)."],"plain_english_summary":"This Airworthiness Directive requires operators of Honeywell ALF502 and LF507 engines to remove specified first rotor sealing plates, first turbine rotor discs and turbine spacers in line with FAA AD 2002-12-08; it takes effect 5 September 2002. (Applicability; Requirement; Compliance)\n\nThe CASA delegate issues the requirement and operators bear the cost and operational timing of removals and replacements under a mandated life‑limit draw‑down because field analysis found lower low‑cycle fatigue limits for some turbine hardware. (Background; Requirement)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing specific fatigue life limits for three turbine components in two engine series. It has not expanded beyond its initial safety purpose."},"complexity_factors":["Very short document (under 300 words)","Only 3 defined component types","Single compliance pathway with reference to external FAA document","No nested exceptions or conditional logic","Clear applicability (specific engine series only)","Simple temporal trigger (effective date and compliance schedule)"],"plain_english_summary":"This AD mandates removal and replacement of certain critical turbine parts in Honeywell ALF502 and LF507 engines before they reach newly determined life limits to address accelerated low-cycle fatigue. It affects operators of aircraft using these engines (e.g., BAe 125 and Bombardier Challenger 600 series).\n\nAdopting FAA AD 2002-12-08 into Australian law (effective 5 Sept 2002), it prevents in-flight engine cracks or failures by aligning Australian maintenance requirements with the U.S. directive."}},"importantCases":[],"_links":{"self":"/api/acts/ad-alf-18-turbine-component-life-limits","history":"/api/acts/ad-alf-18-turbine-component-life-limits/history","analysis":"/api/acts/ad-alf-18-turbine-component-life-limits/analysis","conflicts":"/api/acts/ad-alf-18-turbine-component-life-limits/conflicts","importantCases":"/api/acts/ad-alf-18-turbine-component-life-limits/important-cases","documents":"/api/acts/ad-alf-18-turbine-component-life-limits/documents"}}