FLASHBACK: 'This Is Not a Jet': Pratt & Whitney Explains Why A220/CSeries is Quieter Than Critics Think - The Q400 turboprop is actually louder...
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November 23, 2015 - by Kristine Owram for Financial Post
Note: The CSeries is now called the A220 since acquired by Airbus.
'This is not a jet,' Pratt & Whitney's VP of commercial engine programs, said. 'Even in the Toronto construct they're talking about jets, but it's not a jet, it's a turbofan'
When politicians and activists talk about Porter Airlines' plan to fly "jets" out of Toronto's downtown airport, they show a fundamental misunderstanding of the technology on Bombardier Inc.'s CSeries aircraft, according to the executive who developed the plane's engine.
(Ottawa says 'no' to jets at Toronto island airport, dealing blow to Porter's CSeries plans as well as Quebec Bombardier and protecting Air Canada?)
The federal Liberals have put the kibosh on Porter Airlines' expansion plans, dealing a blow to Bombardier Inc.
"First and foremost, this is not a jet," Graham Webb, vice-president of commercial engine programs at Pratt & Whitney, said in a phone interview from East Hartford, Conn.
In the PurePower engine, the intake fan is separated from the turbine by a gearbox so both can run at optimal speeds. (In this case, the fan moves at about one-third the speed of the turbine. In a conventional jet, the fan and turbine are attached and move at the same speed.)
Because most of the thrust generated by a turbofan comes from the slow-moving air passing through the extra-large fan, less fuel is burned and less noise is generated compared with a typical jet engine.
As a result, noise is reduced by 50 to 75 per cent compared with existing engines and fuel burn is cut by up to 16 per cent.
"I think that as people start to understand this and see the difference in this class of aircraft that heretofore was not in existence, it'll begin to change their perspectives," said Webb, who was the chief engineer on the program and has worked with Bombardier on the CSeries since Day 1.
Existing Q400 turboprop is actually louder than the CSeries
In fact, Webb said Porter's existing Q400 turboprop is actually louder than the CSeries, in the sense that it makes a lower-frequency noise and can be heard at a greater distance. Bombardier confirmed recently that the CSeries is "the quietest in-production commercial jet in its class."