Why is the Progress D-27 a propfan when TP400 a turboprop? Both have swept propellers of comparable diameter. D-27 being 4.5 meters while TP400 is 5.3 meters. Is it the counter rotating props? In which case why is Kuznetsov NK-12 not a propfan?
A propfan should offer speed advantage over turboprops right? But A400M with TP400 is faster than An-70 even though it has lower power to weight ratio and lower output.
By: Multirole - 11th July 2018 at 06:36
It does have a reduction gearbox
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By: MigL - 11th July 2018 at 04:16
Is the prop on the DP-27 directly driven from the turbine shaft ?
IOW, basically a ductless turbofan ?
That is what I consider the difference, a turboprop uses a transmission between prop and turbine shaft.
Or is it just marketing hype ?
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July 11, 2018 at 4:04 am