The Defense Advanced Research Projects Agency (DARPA) said Wednesday it awarded prime contracts to Boeing [BA], Aurora Flight Sciences, Karem Aircraft and United Technologies Corp. [UTX] unit Sikorsky for the agency’s vertical takeoff and landing (VTOL) experimental plane (X-Plane) program.

DARPA seeks to innovate cross pollination between the fixed-wing and rotary-wing worlds to enable radical improvements in vertical and cruise flight capabilities. DARPA said for generations new designs for VTOL aircraft have remained unable to increase top speed without sacrificing range, efficiency or the ability to do useful work.

Boeing's vertical takeoff and landing (VTOL) experimental plane (X-Plane) prototype known as Phantom Swift. Photo: Boeing.
Boeing’s vertical takeoff and landing (VTOL) experimental plane (X-Plane) prototype known as Phantom Swift. Photo: Boeing.

DARPA seeks to develop a technology demonstrator that could achieve a top sustained flight speed of 300-400 knots, raise aircraft hover efficiency from 60 percent to at least 75 percent, present a more favorable cruise lift-to-drag ratio of at least 10 (up from five to six) and carry a useful load of at least 40 percent of the vehicle’s projected gross weight of 10,000-12,000 pounds.

All four companies selected proposed designs for unmanned vehicles, DARPA said, but the technologies that VTOL X-Plane intends to develop could apply equally well to manned aircraft. Another common element among the designs is that they all incorporate multipurpose technologies to varying degrees. Multipurpose technologies decrease the number of systems in a vehicle and its overall mechanical complexity while they also use space and weight more efficiently to improve performance and enable new and improved capabilities.

The next major X-Plane milestone is late 2015, when the four companies are required to submit preliminary designs. At that point, DARPA said it plans to review the designs to decide which to build as a technology demonstrator, with the goal of performing flight tests in the 2017-2018 timeframe.

Boeing said in a statement it offered its Phantom Swift prototype that features two large lift fans inside the fuselage that provide efficient vertical lift. Once the aircraft transitions into cruise mode, the fans are covered. Phantom Swift also features smaller ducted fans on the wingtips that provide forward thrust and additional lift and control in hover.

Boeing said it intends to continue developing its technology through a $17 million agreement with DARPA’s tactical technology office. Sikorsky in November received a contract worth around $14.3 million, according to a notice posted on Federal Business Opportunities (FBO). Aurora spokeswoman Patricia Woodside declined comment Wednesday. Sikorsky said the overall X-Plane program is a 52-month, $130 million effort.

Sikorsky is teaming with Lockheed Martin [LMT] for its X-Plane development called Unmanned Rotor Blown Wing. Sikorsky said Rotor Blown Wing represents a unique integration of fixed wing aerodynamics and advanced rotor control to provide a low complexity configuration capable of meeting the challenging DARPA program goals. During Phase 1, Sikorsky and Lockheed Martin will conduct trade studies and develop the initial design.

Aurora said its X-Plane offering called Lightning Strike is designed for efficient hover and high speed by tightly integrating propulsion into the air vehicle’s aerodynamic design. Aurora said it is a pioneer in ducted-fan and hybrid-propulsion aircraft.