>>1169787>>1169798Well stop comparing apples and oranges. Conventional airliners get from point A to point B using less gas but a hell of a lot slower. The turbofan is the most efficient engine configuration in this scenario. Sustained long-distance flight at Mach 2 requires a completely different airframe and powerplant combination. You can't accurately compare the two from an efficiency standpoint; they are two different classes of aircraft. You can compare them from an economic standpoint, because that is where the two types of airliners actually compete.
You wouldn't compare an Ameriflight B1900 or Metro III with a FedEx MD-11 because the two operate in completely different flight regimes regardless if it is still delivering mail and packages.
