Forget the VTOL patent I posted on this blog last week. That's old news.
Walking amidst the exhibits at the Association of the US Army convention, I found out about a completely different kind of aircraft that may finally solve one of the most challenging aerodynamic puzzles: how to design an aircraft that can fly both vertically and horizontally without compromising efficiency in either regime.
Boeing has a contract with the Defense Advanced Research Projects Agency to study design concepts for a new breed of hybrid vertical takeoff and landing (VTOL) aircraft. It's called the Disk Rotor, and it looks a lot like this:
I picked these photos off this Swiss web site, but I am reliably informed is very similar to Boeing's concept.
The aircraft achieves vertical lift and hover with rotor blades that fold out from the rotor hub and retract during forward flight. A pair of engines provide the power for forward flight, during which the larger rotor hub functions as a wing.