While we have seen glimpses of how the F-35B—the short take-off vertical landing variant of the F-35 Lightning II—works, here's an amazingly detailed video showing its transforming capabilities in flight, which was posted anonymously in YouTube last week. According to Flight Global, this sophisticated war machine—which is now in its testing phase—won't see real action any time soon, as its engine is getting redesigned turbine blades. Update: one of the authors of the—apparently previously classified—video sends us more detailed information about what this really is.

The video was done two years ago for Northrop Grumman. Our reader was one of the three people who did it and he's quite surprised to find it online, since it is under NDA.

The one depicted is the X-35 [the prototype that won the contract for the Joint Strike Fighter and became the F-35]. I don’t know who posted it on YouTube, but the level of NDA’s was substantial where we were not even allowed to showcase it on our demo reel.

My guess is that, since the cat has been out of the bag for a long time, the NDA is no longer applicable. [Flight Global]

Watching him explain it, the genius of Dr. Bevilaqua's F-35B Shaft Driven Lift Fan is obvious. After all, the invention is quite simple. According to Bevilaqua, the best way to create power from the engine is by using a turbine. That power then gets moved forward using a shaft that connects to a fan, providing the vertical lift on the front of the plane—and all while the turbine exhaust is redirected to the ground to lift the back of the plane.

The result is a supersonic plane with great maneuverability. Like a car, Bevilaqua explains, the pilot starts the engine, engages the clutch that activates the lift fan, increases power—and off it goes. To make things even better, the bleed air coming off from the top runs over the winds so the F-35B handles smoothly while going vertically, "like if it was mounted on a hydraulic lift."

The idea, he says, came at the very end of a nine-month study to see if it was possible to do a supersonic successor to the Harrier for the Marine Corp. "I had to come up with a way to increase the thrust of a jet engine so that you could take off vertically, but yet not make it impossible for the airplane to go supersonic."

Dr. Bevilaqua—who started working with Hans von Ohain, the German engineer who invented the jet engine with the Heinkel He 178, and encouraged him to think not about math but about engineering—sketched his first idea on a napkin, which was a turbine with a drive shaft sticking out the front of the engine. He got it to a propulsion expert at Skunk Works to see if it was feasible or not. From there it was transformed from paper dream to reality: Lockheed Martin applied for the patent in 1990, which ended up being one of the factors that landed them the massive $200 billion contract for the Joint Strike Fighter against Boeing's X-32.

[Govexec, Global Security, Skunk Works and Wikipedia via The DEW Line]