Why not just use the larger turbine with the efficiency benefits ? Or does downsizing the turbine save on so much weight that it makes a big enough difference?
Why not just use the larger turbine with the efficiency benefits ? Or does downsizing the turbine save on so much weight that it makes a big enough difference?
The larger turbine (like a PW100 1.8MW in the dash-8 that this demonstrator is replacing) is at peak efficiency (~0.30kg/kWh output SFC) near full load, then it cuts back to 50% power while cruising where it also drops into a less-efficient SFC rate (~0.36) then down again to 20% (~0.45) for descent vs the "always at 100%" 1MW version which stays pretty much pinned at 0.30kg/kWh sfc sweet spot during all of the flight except descent where it also drops back and takes an efficiency hit.
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