Also, perhaps it doesn't have to travel as far as conventional airplanes. Perhaps it can be okay to be twice as slow (because of more stops and lower powered en

Also, perhaps it doesn't have to travel as far as conventional airplanes. Perhaps it can be okay to be twice as slow (because of more stops and lower powered engines) if it's only slightly cheaper. Trains and long distance busses are still around for routes that are also trafficked by airplanes. Presumably because they are often cheaper.