{"id":"F2006B06386","name":"AD/PW100/7 - High Pressure Turbine Disc Replacement","slug":"ad-pw100-7-high-pressure-turbine-disc-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47678,"registerId":"commonwealth-F2006B06386-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PW100/7 - High Pressure Turbine Disc Replacement","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)  \nPratt and Whitney Canada Turbine Engines \\- PW100 Series\n\nAD/PW100/7 High Pressure Turbine Disc Replacement 3/94 DM\n\nApplicability: All PW100 series engines incorporating high pressure turbine discs, P/No. 3035711 or 3038411.\n\nRequirement: For PW100 series engines that incorporate high pressure turbine disc P/No 3035711 or 3038411, remove affected discs from service and replace with new or serviceable discs with less than 10,000 cycles since new (CSN) in accordance with the schedule detailed in Compliance below.\n\nNote: Transport Canada AD CF-94-01 also refers.\n\nCompliance: Effective 19 January 1994;\n\nReplace affected HPT discs as follows:\n\nDiscs with 13,000 CSN or more, within the next 1,000 cycles but not to exceed 15,000 CSN.\n\nDiscs with 12,000 CSN or more but less than 13,000 CSN, within the next 1,250 cycles but not to exceed 14,000 CSN.\n\nDiscs with 10,000 CSN or more but less than 12,000 CSN, within the next 1,750 cycles but not to exceed 13,250 cycles.\n\nDiscs with 8,000 CSN or more but less than 10,000 CSN, within the next 2,500 cycles but not to exceed 12,000 CSN.\n\nDiscs with less than 8,000 CSN, not to exceed 10,000 CSN.\n\nAll replacement discs with P/No. 3035711 or 3038411 installed per this AD must be retired from service before exceeding 10,000 CSN.\n\nBackground: There have been two reported instances of high pressure turbine disc rim fractures which resulted from low cycle fatigue. One of these events was uncontained.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The AD's scope is limited to PW100 series engines with high pressure turbine discs P/No. 3035711 or 3038411 and prescribes cycle-based removal and replacement (Applicability; Compliance). The instrument defines its target population and retirement limits explicitly; nothing in the text indicates an expansion or narrowing from an earlier stated intent."},"complexity_factors":["Tiered compliance windows tied to multiple CSN bands (5 bands) creating staggered deadlines and absolute CSN caps (Compliance section).","Mandatory limit that replacement parts themselves must have <10,000 CSN and be retired before 10,000 CSN, requiring life-tracking of replaced components.","Immediate effective date (19 January 1994) imposing prompt operational planning and logistics for affected fleets.","Narrow applicability to PW100 engines with specific part numbers reduces scope but concentrates operational impact on affected operators and maintenance providers (Applicability).","Cross-reference to Transport Canada AD creates alignment and potential international coordination or supply implications (Note).","Record-keeping and scheduling burdens for operators to monitor cycles and manage phased removals, plus potential parts-supply constraints."],"plain_english_summary":"This Airworthiness Directive requires operators of Pratt & Whitney Canada PW100 engines fitted with high‑pressure turbine discs P/No. 3035711 or 3038411 to remove and replace those discs on a cycle‑based schedule. Replacement discs installed under the AD must have fewer than 10,000 cycles since new and be retired before reaching 10,000 CSN. The measure responds to two reported rim fractures from low‑cycle fatigue; operators bear the cost and responsibility for arranging and proving compliance, which CASA enforces."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in specific engine models. It has not expanded beyond its original purpose of mandating turbine disc replacement to prevent fatigue failures."},"complexity_factors":["Single, clearly defined mechanical issue with specific part numbers","Straightforward tiered compliance schedule based on one variable (cycles since new)","No cross-references to other legislation beyond a single note about a Canadian equivalent directive","Limited conditional logic — five distinct categories with clear numerical thresholds","No defined terms section or interpretive provisions","Single requirement (replace discs) with one additional restriction (10,000 CSN cap on replacements)"],"plain_english_summary":"This CASA Airworthiness Directive mandates replacing Pratt & Whitney Canada PW100 high‑pressure turbine discs (parts 3035711 or 3038411) because fatigue cracks — including one uncontained failure — risk catastrophic engine damage. It applies to operators of aircraft with those discs.\n\nReplacement deadlines scale to each disc’s accumulated flight cycles (so the most‑worn are replaced first; the least‑worn must be replaced before 10,000 cycles). Any disc installed under this AD must never exceed 10,000 total cycles."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pw100-7-high-pressure-turbine-disc-replacement","history":"/api/acts/ad-pw100-7-high-pressure-turbine-disc-replacement/history","analysis":"/api/acts/ad-pw100-7-high-pressure-turbine-disc-replacement/analysis","conflicts":"/api/acts/ad-pw100-7-high-pressure-turbine-disc-replacement/conflicts","importantCases":"/api/acts/ad-pw100-7-high-pressure-turbine-disc-replacement/important-cases","documents":"/api/acts/ad-pw100-7-high-pressure-turbine-disc-replacement/documents"}}