The US Defense Advanced Research Projects Agency (DARPA) has awarded four prime contracts for Phase 1 of its vertical take-off and landing experimental aircraft (VTOL X-Plane) programme.
Winners Aurora Flight Sciences, Boeing, Karem Aircraft and Sikorsky Aircraft, have all proposed unmanned vehicle designs for the programme, which seeks development of a high-speed VTOL aircraft with the hover capability of a helicopter, according to a DARPA statement.
Incorporating multipurpose technologies to varying degrees, all designs reduce the number of systems in a vehicle and its overall mechanical complexity, while boosting performance and enabling new and enhanced capabilities, it added.
DARPA programme manager Ashish Bagai said the selected proposals aim to create new technologies and also incorporate existing ones that have not been successfully developed to date by VTOL designs.
"We're eager to see if the performers can integrate their ideas into designs that could potentially achieve the performance goals we've set," Bagai said.
"All designs reduce the number of systems in a vehicle and its overall mechanical complexity."
Valued at $130m, the VTOL X-Plane programme is a 52-month effort aimed at developing and flying an experimental aircraft capable of exceeding 300kt, with a hover efficiency of 75%, useful load capacity, and a cruise lift-to-drag ratio of ten or more, which is twice the aerodynamic efficiency of existing VTOL aircraft.
The demonstrator aircraft is also required to carry a useful load of at least 40% of its gross weight, including a payload weighing 15.5% of gross weight.
All companies will submit preliminary designs late next year to enable DARPA to review the designs to make a decision on which to build as a technology demonstrator for planned flight trials in the 2017 to 2018 timeframe, it added.