Pratt & Whitney is reported to be investigating several incidents of excessive vibration by its PW1000G engines in the Airbus A320neo aircraft, though the possible cause and full extent of the problem is not known, according to anonymous sources cited by Bloomberg.
The same report indicated that pilots on some A320neo flights received alerts about high vibration levels. It also noted that the U.S. Federal Aviation Administration has taken up the matter and is working with Pratt & Whitney to determine the cause.
The PW1000G is a high-bypass geared turbofan (GTF) engine that is one option available to operators of A320neo narrow-body jets. It’s also available on the Airbus A220, Ebraer E-Jet E2, Irkut MC-21, and Mitsubishi Regional Jet.
The GTF engine is the result of a 20-year R&D program reportedly costing up to $10 billion. The design features an engine fan separated from the low-pressure compressor and turbine, so that each module operates at optimal speeds. The result is lower engine weight and greater fuel efficiency. Pratt & Whitney claims its GTF engines offer 16% better fuel efficiency and 50% lower NOx emissions than the regulatory standard, and a 75% smaller “noise footprint.”
The current vibration issue is the second apparent problem this year for the engine, though not obviously related to the earlier issue.
In early February, Airbus halted all deliveries of its best-selling A320neo featuring the PW1100G geared-turbofan engine, after the European Aviation Safety Agency issued an emergency airworthiness directive warning of potential in-flight engine failure. Four engines experienced in-flight failures, according to subsequent reports, and P&W later determined the cause to be some recently executed design revisions to the “knife-edge seal attached to thePW1000G’s high-pressure compressor aft hub.”
Engine production was halted, the design change was reversed, and the engine builder was able to resolve the shutdown issue. The EASA directive was withdrawn.