By more economical I only mean 'burns less fuel'. I'm under the impression that at optimal cruise speed and altitude a turbofan will burn less fuel per mile per passenger than a turboprop, but I might be wrong. I'm also under the impression that this doesn't mean turbofans burn less fuel for every mission, that over shorter distances the time taken to reach the optimal cruise doesn't allow for the efficiency of turbofans to come into effect.
Also, unrelated to the efficiency of the aircraft, does the speed of jet aircraft play a significant role in the revenue of airlines? Does the speed increase of turbofans over turboprops mean more flights, or is this time saving not of great significance when designing and selecting aircraft?
