{"id":"F2008L00881","name":"AD/PW200/2 - Compressor Turbine Disk Retaining Nut","slug":"ad-pw200-2-compressor-turbine-disk-retaining-nut","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":73004,"registerId":"commonwealth-F2008L00881-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Pratt and Whitney Canada Turbine Engines","sectionType":"division","heading":"Pratt and Whitney Canada Turbine Engines - PW200 Series","content":"### Pratt and Whitney Canada Turbine Engines - PW200 Series\n\n| AD/PW200/2 | Compressor Turbine Disk Retaining Nut | 4/2008 |\n| ---------- | ------------------------------------- | ------ |\n\n| Applicability: | PW206A Serial No. PCE-BA0031 and earlierPW206B Serial No. PCE-BB00126 and earlierPW206B2 Serial No. PCE-BJ0369 and earlierPW206C Serial No. PCE-BC0605 and earlierPW206E Serial No. PCE-BE0048 and earlierPW207C Serial No. PCE-BH0054 and earlierPW207D Serial No. PCE-BF0135 and earlierPW207E Serial No. PCE-BG0106 and earlierPW207K Serial No. PCE-BK0032 and earlier                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Inspect the compressor turbine (CT) disk bore area for damage and if any damage is noticed, replace the CT disc before next flight, in accordance with P&WC SB PW200-72-A28280 R4 or later revisions approved by Transport Canada; andReplace the existing CT disc retaining nut and associated hardware.Compliance with earlier versions of SB PW200-72-A28280 requirements prior to the effective date of this AD satisfies the corrective action requirements of this AD.Note: Transport Canada AD CF-2007-24R1 dated 21 December 2007 refers.                                                                                                                                                                                                                                                                                                                                                                                                                                                        |\n| Compliance:    | 1. For engines that have never had a shop visit and have accumulated 4000 CT cycles or more since new, orEngines that have accumulated 2700 CT cycles or more since:a) last shop visit; orb) last CT disc inspection; orc) incorporation of SB. PW200-72- 28287:Within 1150 hrs of engine operating time since 28 April 2006 (original issue date of SB PW200-72-A28280), but not later than 10 June 2008.2. For engines that have never had a shop visit and have accumulated less than 4000 CT cycles since new, before the engine reaches 4000 CT cycles or not later than 10 June 2008, whichever occurs later.3. For engines that have accumulated less than 2700 CT cycles since:a) last shop visit; orb) last CT disc inspection; orc) incorporation of P&WC SB pw200-72-28287:Before the engine reaches 2700 CT cycles or not later than 10 June 2008 whichever occurs later.                                                                                                                    |\n|                | This Airworthiness Directive becomes effective on 10 April 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |\n| Background:    | PW206 and PW207 Compressor Turbine (CT) Disk bore areas may experience impact damage resulting from bending or fracture of the CT Disk Retaining Nut castellations. Damage of the CT disk bore area can reduce LCF capabilities of the CT disk, resulting in disk fracture.To preclude any potentially hazardous situation precipitated by a damaged CT disc, P&WC issued Alert Service bulletin PW200-72-A28280, requiring inspection of the CT disc bore area for damage and replacement of the existing Disk Retaining Nut with an improved design nut.The most recent compliance data indicates that the majority of the affected engines, particularly those with high in-service time, still have not been inspected to SB PW200-72-A28280 requirements and as such, are potentially susceptible to CT disc damage. This AD is issued to mandate the inspection of the CT disc bore area and replacement of the existing Disk Retaining Nut, in accordance with SBPW200-72-A28280 R4 instructions. |\n\n![](image.001.png)  \nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n26 February 2008","sortOrder":0},{"sectionNumber":"AD/PW200/2","sectionType":"part","heading":"AD/PW200/2","content":"## AD/PW200/2","sortOrder":1},{"sectionNumber":"Compressor Turbine Disk Retaining Nut","sectionType":"part","heading":"Compressor Turbine Disk Retaining Nut","content":"## Compressor Turbine Disk Retaining Nut","sortOrder":2},{"sectionNumber":"4/2008","sectionType":"part","heading":"4/2008","content":"## 4/2008","sortOrder":3}],"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":6,"scope_assessment":{"changed":false,"description":"The AD converts P&WC's Alert Service Bulletin PW200-72-A28280's recommended inspections and nut redesign into mandatory regulatory requirements for the listed serial-numbered engines, with specified compliance deadlines. It does not expand mandated actions beyond inspection and retaining-nut/hardware replacement, and it accepts prior compliance with earlier SB versions (Requirement; Compliance; Note)."},"complexity_factors":["Applicability limited to multiple PW206/PW207 variants by specific serial-number cut-offs (Applicability section) — requires checking serial records.","Mandated actions combine immediate safety action (replace CT disc if damage is found before next flight) with a phased compliance program for inspections and nut replacement (Requirement; Compliance section).","Multiple, overlapping compliance triggers and deadlines tied to CT cycles, time since last shop visit/inspection/SB incorporation, and a calendar effective date (Compliance section) — operators must determine which trigger applies.","Reliance on external documents and approvals: corrective action must follow P&WC SB PW200-72-A28280 R4 or later revisions approved by Transport Canada; earlier SB compliance is accepted (Requirement; Note).","Cross-reference to Transport Canada AD CF-2007-24R1 (Note) creates regulatory interdependence.","Operational impacts: potential immediate grounding until replacement if damage is detected (Requirement), and logistical/financial burden for parts, labour and scheduling to meet phased thresholds (Background; Compliance).","Enforcement and change control: Transport Canada approval controls which SB revisions satisfy the AD, introducing administrative discretion (Requirement)."],"plain_english_summary":"This Airworthiness Directive requires operators of specified Pratt & Whitney Canada PW200-series engines (listed by serial number) to inspect the compressor turbine (CT) disk bore for damage and, if any is found, replace the CT disk before next flight. It also mandates replacement of the CT disk retaining nut and associated hardware in accordance with P&WC Service Bulletin PW200-72-A28280 R4 (or later approved revisions). It affects engine operators and maintenance organisations who must schedule inspections and hardware replacement and bear related costs and downtime."},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific mechanical defect in specific Pratt & Whitney Canada engine models. The directive does not expand beyond its original safety purpose of preventing compressor turbine disk failures through inspection and hardware replacement."},"complexity_factors":["Multiple conditional compliance pathways based on engine service history (never had shop visit vs. has had shop visit)","Nested thresholds: different cycle counts trigger different deadlines (2700 vs 4000 CT cycles)","Cross-reference to external technical document (P&WC Service Bulletin PW200-72-A28280 R4) which contains the actual inspection procedures","Date-based and cycle-based compliance criteria operating simultaneously ('whichever occurs later')","Specific serial number applicability requiring individual engine identification","Grandfathering clause allowing compliance with earlier versions of the service bulletin to satisfy the AD"],"plain_english_summary":"This CASA Airworthiness Directive mandates inspection of the compressor turbine disk bore and replacement of the retaining nut and related hardware on specified Pratt & Whitney Canada PW200-series helicopter engines. It affects owners/operators of listed serial-number engines and imposes compliance deadlines tied to accumulated cycles and prior service. The measures address risk of compressor-turbine disk damage and potential disk fracture, preventing catastrophic engine failure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pw200-2-compressor-turbine-disk-retaining-nut","history":"/api/acts/ad-pw200-2-compressor-turbine-disk-retaining-nut/history","analysis":"/api/acts/ad-pw200-2-compressor-turbine-disk-retaining-nut/analysis","conflicts":"/api/acts/ad-pw200-2-compressor-turbine-disk-retaining-nut/conflicts","importantCases":"/api/acts/ad-pw200-2-compressor-turbine-disk-retaining-nut/important-cases","documents":"/api/acts/ad-pw200-2-compressor-turbine-disk-retaining-nut/documents"}}