The Billion-Dollar Bet On Jet Tech That's Making Flying More Efficient

A sad thing is we could get 10-15% efficiency just by allowing great circle routes, rather than the "highways in the sky" model, but there are agency issues (benefits go to private carriers, but ATC is paid from general purposes taxation, so efficiency improvements don't go directly to FAA) preventing it.

(of course, any engine efficiency advantages would be additive to this as well, but a policy solution and IT solution seems like it should be easier than a science/engineering solution)