{"id":"F2006L01346","name":"AD/AL501/1 - Second Stage Turbine Wheels","slug":"ad-al501-1-second-stage-turbine-wheels","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":58866,"registerId":"commonwealth-F2006L01346-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Rolls Royce (Allison) Turbine Engines - ","sectionType":"division","heading":"Rolls Royce (Allison) Turbine Engines - AL501 Series","content":"### Rolls Royce (Allison) Turbine Engines - AL501 Series\n\n| AD/AL501/1 | Second Stage Turbine Wheels | 6/2006 |\n| ---------- | --------------------------- | ------ |\n\n| Applicability: | Rolls Royce (formerly DETROIT DIESEL ALLISON) Model 501-D13 series engines which incorporate P/N 6829072 and 6847112 second stage turbine wheels with the serial numbers listed as listed in FAA AD 75-22-05. |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Remove from service second stage turbine wheels in accordance with the schedule in paragraphs l.A. B, C, and D of FAA AD 75-22-05.Note: FAA AD 75-22-05 Amdt 39-2391 refers.                                  |\n| Compliance:    | As detailed in FAA AD 75-22-05 with a revised effective date of 8 June 2006.                                                                                                                                  |\n|                | This Airworthiness Directive becomes effective on 8 June 2006.                                                                                                                                                |\n| Background:    | This AD details the requirements for removal of certain second stage turbine wheels from service.                                                                                                             |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n28 April 2006","sortOrder":0},{"sectionNumber":"AD/AL501/1","sectionType":"part","heading":"AD/AL501/1","content":"## AD/AL501/1","sortOrder":1},{"sectionNumber":"Second Stage Turbine Wheels","sectionType":"part","heading":"Second Stage Turbine Wheels","content":"## Second Stage Turbine Wheels","sortOrder":2},{"sectionNumber":"6/2006","sectionType":"part","heading":"6/2006","content":"## 6/2006","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard technical airworthiness directive with narrow, specific scope. It addresses a single safety issue (defective turbine wheels) for a specific engine model. There is no indication of scope creep; it performs exactly the function intended for ADs."},"complexity_factors":["Very short document (approximately 200 words)","Only 2 defined part numbers and 1 referenced FAA directive","Single operative requirement with no exceptions or conditional logic","No nested definitions or cross-references to other Australian legislation","Straightforward compliance mechanism (adopt foreign standard with new effective date)"],"plain_english_summary":"This mandatory CASA Airworthiness Directive requires operators of aircraft with Rolls Royce (formerly Detroit Diesel Allison) Model 501‑D13 engines to remove specified second‑stage turbine wheels (part nos. 6829072, 6847112; serials listed in FAA AD 75‑22‑05) per the FAA removal schedule. It adopts the US safety action into Australian law (effective 8 June 2006) to prevent catastrophic engine failure from suspected wheel defects."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The directive adopts the removal requirements set out in FAA AD 75‑22‑05 for the specified wheels; it does not expand the listed parts or serial numbers. The only explicit alteration in the text is a revised effective date of 8 June 2006 (Compliance/Effective date)."},"complexity_factors":["Cross‑reference to an external instrument (FAA AD 75‑22‑05) rather than standalone rules (Requirement/Compliance)","Technical specificity: particular part numbers and serial numbers determine applicability (Applicability)","Prescriptive removal schedule split into multiple paragraphs (FAA AD paragraphs l.A, B, C, D) increasing procedural steps (Requirement)","Operational impact contingent on maintenance logistics and parts availability (implicit in Compliance/effective date)","Regulatory adoption mechanics: CASA adoption of an FAA AD with a revised effective date requires agencies/operators to track both instruments (Compliance/Effective date)"],"plain_english_summary":"**What it does:** This Airworthiness Directive requires operators of Rolls Royce (Allison) Model 501‑D13 engines fitted with second‑stage turbine wheels P/N 6829072 or 6847112 (serial numbers listed in FAA AD 75‑22‑05) to remove those wheels from service on the schedule set out in FAA AD 75‑22‑05. CASA adopted the FAA AD with an effective date of 8 June 2006.\n\n**Who pays and what changes:** Engine operators pay for removal and any replacements, must inspect serial numbers and meet the FAA‑prescribed timing, and may face aircraft downtime or parts‑supply constraints to comply."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-al501-1-second-stage-turbine-wheels","history":"/api/acts/ad-al501-1-second-stage-turbine-wheels/history","analysis":"/api/acts/ad-al501-1-second-stage-turbine-wheels/analysis","conflicts":"/api/acts/ad-al501-1-second-stage-turbine-wheels/conflicts","importantCases":"/api/acts/ad-al501-1-second-stage-turbine-wheels/important-cases","documents":"/api/acts/ad-al501-1-second-stage-turbine-wheels/documents"}}