Reply #1: You want fuel efficient aircraft?

[RaleighNCDUer]

Try Zeppelins.

They may not be as fast as jets, but they carry far more cargo & passengers per gallon of fuel than any aircraft today. With modern computer systems they'd be far less prone to the kind of weather accidents that ended their use in the 30s, and even then they were far safer as transport than normal aircraft, if you considered total fatalities per miles flown.

I'd far rather spend 24 hours on a Zeppelin crossing the Atlantic than 6 hours on a jet.