DARPA’s VTOL Experimental Plane (VTOL X-Plane) program seeks to enable radical improvements in vertical takeoff and landing (VTOL) flight through innovative cross-pollination between the fixed-wing and rotary-wing worlds.
In an important step toward that goal, DARPA has awarded prime contracts for Phase 1 of VTOL X-Plane to four companies: Aurora Flight Sciences, Boeing, Karem Aircraft and Sikorsky. Three of the four—Boeing (top), Karem Aircraft (middle) and Sikorsky (bottom)—provided concept images of their proposed designs.
Rather than tweaking past designs and technologies, VTOL X-Plane challenges industry and innovative engineers to create a single hybrid aircraft that would concurrently push the envelope in four areas:
- Speed: Achieve a top sustained flight speed of 300 kt-400 kt
- Hover efficiency: Raise hover efficiency from 60 percent to at least 75 percent
- Cruise efficiency: Present a more favorable cruise lift-to-drag ratio of at least 10, up from 5-6
- Useful load capacity: Maintain the ability to perform useful work by carrying a useful load of at least 40 percent of the vehicle’s projected gross weight of 10,000-12,000 pounds
The VTOL X-Plane program is scheduled for three phases over 52 months between October 2013 and February 2018, with the first demonstration flight slated for 42 months after the initial award. The total planned budget is $130 million; DARPA has allotted $47 million in Phase I for multiple individual awards for preliminary concept design and technology maturation. DARPA intends to choose one of the Phase I prime performers to conduct Phase II (design, development and integration) and Phase III (flight-test demonstrations).