Pentagon researchers order plane that takes off and lands vertically with 24 ducted fans
The experimental unmanned plane is powered by a hybrid electric engine system
No one has ever seen any airplane like this, except on computer animation. Now, some of the world’s top aeronautical engineers are going to build it for real.
The plan calls for constructing a six-ton unmanned, remote controlled plane the size of a business jet with 24 spinning propellers embedded in its huge moveable wings that allow it to magically hover in midair.
It’s an experimental airplane they call LightningStrike.
The design — by Aurora Flight Sciences Corporation — may look pretty strange, but on Thursday, it beat big-name companies Sikorsky and Boeing to win a contract from the Defense Advanced Research Projects Agency, or DARPA, the Pentagon’s research arm.
DARPA is trying to develop vertical takeoff and landing planes, called VTOLs, that fly faster and burn less fuel than current VTOLs, like the V-22 and MV-22 Osprey. You may have seen the Osprey, which is noticeable by its two big tilt-rotors on each side. These aircraft escort President Obama’s Marine One helicopters.
Why VTOLs matter
War planners place high value on nimble aircraft that can land and take off virtually anywhere — no runway required.
But traditionally, helicopters can’t pack much speed without using a lot of fuel.
LightningStrike’s propulsion system is hybrid electric, which is designed to be more efficient. Engineers said they’ve designed it to be faster than the Osprey.
“Instead of taking two big powerful thrusters, we have 24 of them,” said Aurora Chairman and CEO Dr. John Langford. “We distribute that same energy over 24 fans … has less blast, less heat, is quieter and less disruptive, which means it can get into places that the V-22 can’t. Part of the idea of this is to make it more practical.”
The V-22 is in no danger of being replaced by the LightningStrike, which will be built as a technology demonstration experimental aircraft. But DARPA hopes to learn from it and extrapolate data that might be used to develop future military aircraft, said Dr. Ashish Bagai, program manager of DARPA’s Tactical Technology Office.
It’s possible that someday ducted fan electric hybrid propulsion VTOL aircraft might be used as troop transports or even in combat situations, he said.
Aurora expects to start test flying its new plane sometime around 2018. But building a successful prototype of LightningStrike will come with big challenges.
Engineering VTOLs to smoothly switch flying vertically to flying horizontally is always a difficult hurdle, said Bagai.
Unique challenges to building LightningStrike, he said, will include how to apply electric flight to VTOLs and how to push the plane’s speed capability to their goal of 300 knots (345 mph).
Aurora’s plans call for the plane’s power plant to be the Rolls-Royce AE 1107C turboshaft engine, the same model used in the Osprey. The engine will turn three Honeywell electric generators.
Then those generators will power 18 fans that each will live inside ducts along the wings.
Toward the front of the plane, embedded inside two stubby wing-like protrusions called canards, are six additional fans. These fans thrust the plane into the air. The plane’s wings twist forward as the aircraft shifts from vertical to horizontal flight.
“What you’re starting to see here are designs and configurations and applications of technologies that have never been done before,” Bagai said. “I think we have our work cut out for us.”