Rolls-Royce Engine to Power Experimental Military Plane
The collective force of 24 fans produces thrust for the XPlane.
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As a subscriber you can listen to articles at work, in the car, or while you work out. Subscribe NowIt’s called the X-Plane—an odd-looking, but formidable experimental plane that will be powered by the ingenuity of Hoosiers working at Rolls-Royce in Indianapolis. Capable of vertical take-offs and landings, the unmanned defense aircraft is assigned the task of “redefining the future of vertical flight.” To do that, a team of about 35 Rolls-Royce workers is re-tooling an existing engine so it can push the plane farther and faster, bearing more load than ever before.
Designing and building the new engine is part of an $89 million contract with the Defense Advanced Research Projects Agency (DARPA); Rolls-Royce is one of three partners tasked with “pushing the envelope” on propulsion technology. The X-Plane’s list of goals is ambitious: achieve a top speed of 300 to 400 knots, hover more efficiently and carry a load that’s at least 40 percent of the aircraft’s weight.
Rolls-Royce’s advanced aerospace technology unit in Indianapolis, LibertyWorks, is leading the engine work and believes it will achieve the project’s goals. LibertyWorks Chief Operating Officer Mark Wilson says the team is creating a turbo-electric distributed propulsion system for the X-Plane—what he calls “a brand new concept” for the industry.
The team is taking a gas turbine engine made for the V-22 Osprey aircraft—also produced in Indianapolis—hot off the production line and equipping it with new technology for the X-Plane. The concept is what gives the aircraft its unusual look; 24 fans—18 of which are on the tilting wings—are powered by the single engine. The collective force of the fans produces the thrust.
“In the [V-22 Osprey], the engine drives a propeller or rotor with a mechanical shaft,” says Wilson. “What we’re doing differently in [the X-Plane] is, we’re using the engine to power some electrical generators, and then powering these multiple fans with electricity instead of a mechanical shaft. That creates an efficient distribution of power and allows us to also power about 24 fans, as opposed to one or two propellers you see in a normal aircraft.”
The project demands the X-Plane to have a longer range and go much faster than its predecessors; Wilson says adding power while decreasing weight is a delicate balance. He believes controlling the electrical distribution system efficiently will minimize the amount of excess components typically needed.
“One of the challenges in vertical take-off and landing aircraft is always weight—trying to make the system as light as possible, so we can maximize the ability to carry the load,” says Wilson. “Even using electricity, trying to develop a system that minimizes the weight in terms of the power distribution that you need has been a big challenge.”
The first phase of the program, which involved the design details, was completed several months ago. The team will complete component testing later this year, run the full engine system in 2017 and perform the X-Plane’s flight test in 2018.
The program’s team includes Virginia-based Aurora Flight Services Corp. and Honeywell; the group believes, if successful, the X-Plane will “redefine the future of vertical flight” and revolutionize the U.S. military’s mission capabilities. Wilson says LibertyWorks takes pride in developing new technology and advancing it to demonstration with “real hardware.”
“Getting to flight test and showing we can overcome the challenges of this program is going to be extremely, extremely exciting—and we’re looking forward to that demonstration,” says Wilson. “We’re thrilled to be on the ground floor of this technology development.”
Wilson says the X-Plane’s engine will be the first of its kind and a “culmination” of Rolls-Royce technologies.
Wilson says the X-Plane aims to have longer range and fly much faster than the V-22 Osprey, which is the current standard for similar missions.