EASA AD CF-2025-08
Engine — High Pressure Turbine (HPT) Disk — Improper Rework
Summary
Canadian Airworthiness Directive CF-2025-08 addresses an unsafe condition involving Pratt & Whitney Canada Corp. PW545A, PW545B, and PW545C engine high pressure turbine (HPT) disks. The directive targets HPT disks with improper rework that may introduce residual stress, potentially leading to disk failure and engine damage. It mandates removal and replacement of affected disks by specified revised life limits to ensure continued airworthiness.
What Changed
CF-2025-08 introduces a mandatory requirement to remove and replace seven specific HPT disks identified as having been improperly reworked, based on a revised life limit established by stress analysis. It also prohibits installation of affected disks that have exceeded their revised life limits. This is a new directive responding to findings from Pratt & Whitney Canada and is not an amendment to a previous AD.
Why It Matters
This directive is critical for operators and maintenance organizations to prevent uncontained HPT disk failures that could cause severe engine and aircraft damage. Compliance ensures safety by addressing a latent manufacturing defect not detectable by standard inspections. It also clarifies life limits and installation prohibitions, aiding compliance teams in managing affected engine components.
What To Do
Operators must identify engines containing affected HPT disks and remove and replace these disks before reaching the revised life limits specified in Pratt & Whitney Canada Service Bulletin PW500-72-30572 Revision 1. Installation of affected disks beyond their life limits is prohibited from the effective date of 2025-02-24. Earlier compliance with previous versions of the service bulletin also satisfies the directive requirements.