The Defense Advanced Research Projects Agency (DARPA), the Pentagon’s research department, recently announced that it has awarded Phase 2 contract for its experimental VTOL X-Plane to Aurora Flight Sciences, which beat out other heavy-hitting companies like Sikorsky and Boeing.
For years, engineers have been trying to improve vertical takeoff and landing (VTOL) capabilities in military aircraft—a process that has presented an array of give-and-take design challenges, such as how to enable good hovering without sacrificing forward flight speed.VTOL aircraft, like the V-22 Osprey, can take off and land anywhere (like a chopper) and are capable of achieving plane-like speeds. As a result, the military regards them as a highly lucrative technology for use in remote or hard-to-reach areas. (Plus, watching gifs of their rotors shifting between horizontal and vertical is hypnotic and oh-so-satisfying—resembling something out of the Transformers universe.)
Aurora’s VTOL concept holds design promise.
The (unmanned) VTOL X-Plane, nicknamed LightningStrike, integrates two large rear wings and two smaller front canards (short winglets near the aircraft’s nose), which, together, rotate to direct fan thrust rearward for forward flight or downward for hovering.
LightningStrike’s propulsion system is hybrid-electric, running on electricity generated by the aircraft’s turbine engine, and is designed to be more efficient, quieter, and release less heat. The craft incorporates the Osprey’s 3 megawatt Rolls-Royce AE 1107C turboshaft engine, mounted in the fuselage, that drives 24 ducted fans (rather than two large thrusters as is the case with the Osprey).
Using electricity to drive the fans simplifies the propulsion system, allowing for better control of each engine cell in flight. Additionally, individual cells can be shut down during flight phases, as needed, increasing the aircraft’s range.
The goal is to push the plane to reach sustained speeds between 345 and 460 mph, carry about 12,000 pounds, and integrate a lift to drag ratio of at least 10 (other VTOL aircraft on the market have a ratio between 5 and 6).
“This VTOL X-plane won’t be in volume production in the next few years but is important for the future capabilities it could enable,” DARPA program manager Ashish Bagai said. “Imagine electric aircraft that are more quiet, fuel-efficient, and adaptable and are capable of runway-independent operations. We want to open up whole new design and mission spaces freed from prior constraints and enable new VTOL aircraft systems and subsystems.”
Your move, Decepticons.