EASA AD CF-2023-60
Engine — Gas Generator Case to Turbine Support Case Retaining Bolts — Inadequate Fatigue Life
Summary
The Canadian Airworthiness Directive CF-2023-60 addresses inadequate fatigue life of gas generator case to turbine support case retaining bolts on Pratt & Whitney Canada PW535E and PW535E1 engines. This directive mandates inspections and replacements of specific bolts to prevent potential fatigue cracking and subsequent engine damage. It applies to all serial numbers of the affected engine models manufactured to specified standards.
What Changed
CF-2023-60 introduces mandatory inspections and replacements of retaining bolts MS9696-08 and MS9489-06 on the gas generator case to turbine support case joint flange. It requires operators to inspect bolts within 400 cycles for certain engines and replace bolts during scheduled maintenance or inspections for all engines. The directive enforces compliance with Pratt & Whitney Canada's Service Bulletin PW500-72-30571 dated June 9, 2023.
Why It Matters
This directive is critical for aviation professionals to prevent fatigue-induced bolt fractures that could lead to flange separation or case failure, potentially causing engine and aircraft damage. Operators and maintenance teams must ensure timely inspections and replacements to maintain engine integrity and airworthiness. Compliance reduces the risk of in-service failures and supports continued safe operation of affected PW535E and PW535E1 engines.
What To Do
Operators must inspect the specified bolts within 400 engine cycles from August 28, 2023, for engines meeting group 1 criteria and repeat inspections every 400 cycles until bolt replacement. For all engines (group 2), bolts must be replaced with new ones at the next scheduled hot section inspection or overhaul. Removed bolts cannot be reused on the affected engines. Compliance must follow the instructions in P&WC Service Bulletin PW500-72-30571 or its approved revisions.
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