These Four Companies Will Build DARPA High-Speed VTOL X-Plane Prototypes

(An artist rendering of the high speed VTOL prototype Aurora Flight Sciences is developing for the latest DARPA X-Plane competition. Image: Aurora Flight Sciences)

The Defense Advanced Research Projects Agency (DARPA) has selected four companies to compete for its Speed and Runway Independent Technologies (SPRINT) X-Plane program, including Boeing subsidiary Aurora Flight Sciences, Bell Textron Inc., Northrop Grumman and Piasecki Aircraft.

The SPRINT program is a joint DARPA/U.S. Special Operations Command effort that aims to design, build, and fly an X-plane to demonstrate the key technologies and integrated concepts that enable a transformational combination of aircraft speed and runway independence. DARPA seeks to use the SPRINT project to develop a proof-of-concept technology demonstrator and its flight test program seeks to validate enabling technologies and integrated concepts that can be scaled to different size military aircraft.

The goal of the program is to provide these aircraft with the ability to cruise at speeds from 400 to 450 knots at relevant altitudes and hover in austere environments from unprepared surfaces.

Phase 1A includes conceptual design, culminating in a formal Conceptual Design Review. The initial SPRINT awards providing funding for each selected company to develop a conceptual design review and includes an executable option to continue work through preliminary design review.

As part of its entry into the SPRINT program, Aurora is designing a high lift, low drag fan-in-wing (FIW) demonstrator aircraft that integrates a blended wing body platform, with embedded engines and moderate sweep, with a vertical flight design comprised of embedded lift fans linked to the engines via mechanical drives. Their design team will leverage past flight programs like the Boeing X-48 blended wing body aircraft and the Aurora Excalibur UAS that combined jet-borne vertical lift with three electric, louvered lift fans that would retract into the wing in forward flight.

“Aurora and Boeing are excited to work with DARPA to develop this revolutionary capability,” said Larry Wirsing, Vice President of Aircraft Development Programs at Aurora Flight Sciences. “This X-plane will demonstrate that a high-speed, vertical lift, blended wing body aircraft will provide superior flexibility and operational performance to the military in the future.”

Bell plans to leverage its extensive investment in High-Speed Vertical Takeoff and Landing (HSVTOL) technology to demonstrate advanced performance capabilities. Bell is currently conducting risk reduction testing at Holloman Air Force Base in New Mexico to demonstrate its folding rotor, integrated propulsion, and flight control technologies using a dedicated test article.

Bell’s HSVTOL technology blends the hover capability of a helicopter with the speed (400+ kts), range, and survivability of jet aircraft.

“Bell is honored to be selected for SPRINT and thrilled to support another X-plane, which will bring unprecedented speed to vertical lift aircraft,” said Jason Hurst, executive vice president, Engineering, Bell. “In our rich 85-year history, Bell has produced memorable X-planes, such as the Bell X-1 and XV-15, and expanded our VTOL aircraft capabilities. This contract award is a testament to Bell's ability to build on past successful high-speed aircraft programs while investing in new research to validate HSVTOL technology.”

DARPA launched its latest X-plane effort November 1, and is targeting first flight of the X-Plane demonstrator "within 42 months," according to Aurora Flight Sciences.