The Defense Advanced Research Projects Agency (DARPA) has selected Aurora Flight Sciences’ LightningStrike for its innovative vertical-takeoff demonstrator. LightningStrike—which will be one of the strangest machines ever to take flight—beat three other equally strange-looking competitors for the win.
Designers have long understood that airplanes and helicopters are both very limited: airplanes can fly fast but not hover, and helicopters can hover but not fly fast. Many have attempted to design and build something that can fly fast and hover, but the resulting aircraft have been awkward and ungainly, inefficient in both hover and forward flight, often dangerous and always extremely expensive. The few that have made it into production, like the V-22 and F-35, have the same drawbacks.
DARPA, which develops far-out ideas for the military, decided a new approach was needed, and began the Vertical Takeoff and Landing Experimental Plane (VXP) program. The idea was to let designers build something completely new, with potential to fly and hover more efficiently than either an airplane or a helicopter. Everyone thought it could be done in theory—hence the many attempts—but could it really work out in practice?
Four groups—Boeing, Aurora, a Lockheed/Sikorsky team, and Karem Aircraft—got some seed money to work on their designs. All four designs are innovative and have great potential in the immediate future, but Aurora’s stands out as by far the strangest.
The airframe itself is weird enough, but what really sets it apart is how it generates thrust. Rather than one or two conventional gas-guzzling engines mechanically linked to turn a propeller (or occasionally two counter-rotating propellers), LightningStrike will hook a single gas-powered generator to 24 small electric motors arrayed across a wing and horizontal stabilizer, which will tilt from vertical to horizontal depending on the desired flight mode. That kind of distributed electric propulsion has never undergone large-scale flight testing, but theoretically it allows much more control over flight: Using sophisticated computers, LightningStrike can fine-tune thrust in different parts of the airplane with a speed and finesse that simply can’t be achieved by big gas-powered engines.
The result will look weird, sound bizarre, and fly unlike anything that has come before, and just may revolutionize flight altogether. There’s only one way to find out, and thanks to DARPA we’ll have that chance.