EASA SIB AV-2008-07
Pratt & Whitney Canada PW530, PW535 and PW545 series engines - No.4 Bearing Carbon Seal Distress
Summary
Transport Canada Service Difficulty Advisory AV-2008-07 addresses a low oil pressure issue in Pratt & Whitney Canada PW530, PW535, and PW545 series engines, specifically related to distress of the No. 4 bearing carbon seal. The advisory highlights occurrences of in-flight engine shutdowns due to oil leakage past the carbon seal on the #4 turbine shaft bearing, affecting aircraft such as the Cessna Citation 560XLS powered by PWC 545B engines.
What Changed
This advisory introduces awareness of a fractured #4 bearing carbon seal causing internal oil leakage and rapid oil loss. Pratt & Whitney Canada plans to issue a Service Bulletin with a redesigned carbon seal to improve durability and pressure balance. Meanwhile, operators are strongly recommended to follow the recently issued P&WC Service Information Letter PW500-033 addressing oil consumption and servicing.
Why It Matters
The issue can lead to low engine oil pressure and potential in-flight engine shutdowns, posing safety risks and operational disruptions. Aviation professionals, including operators and maintenance personnel, must monitor oil servicing closely to prevent overfilling that can exacerbate seal distress. Compliance helps maintain engine reliability and reduces the risk of unscheduled landings or engine failures.
What To Do
Operators and maintenance teams should comply with P&WC Service Information Letter PW500-033 to manage oil consumption and servicing on PW500 series engines. They should monitor oil levels carefully to avoid overfilling and watch for signs of oil leakage around the #4 bearing carbon seal. Await and implement the forthcoming P&WC Service Bulletin with the redesigned carbon seal once published.
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