Next up could be the Boeing Pelican, an experimental concept aircraft from Boeing Phantom Works that makes everything else seem small.

FORBES: The World's Biggest Planes

Also in design: the Fozzie, a concept plane by Boeing Phantom Works.

FORBES: The World's Biggest Planes

"The neat, gee-whiz part is thinking about what would the vehicle itself look like, " said Dick Paul, a vice president with Phantom Works, Boeing's research and development arm.

BBC: NEWS | Science/Nature | Flying cars swoop to the rescue