Dr. Paul Bevilaqua is the aerodynamicist who designed the F-35B shaft-driven lift fan years ago at Skunk Works, Lockheed Martin's advanced technology program. His invention changed short-take off and vertical-landing (STVOL) planes forever, making the Lightning II the first supersonic aircraft with this capability. To honour him, Lockheed Martin has released this new video, in which Dr. Bevilaqua explains how the project went from "napkin to production."
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 aeroplane 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.