Boeing company Aurora Flight Sciences is designing an X-plane that uses fan-in-wing (FIW) technology, delivering high-speed, runway-independent mobility for contested environments.
This work is part of the Defense Advanced Research Projects Agency (DARPA) Speed and Runway Independent Technologies (SPRINT) program, which aims to design, build, and fly an X-plane that demonstrates key technologies and integrated concepts for a combination of aircraft speed and runway independence.
Aurora and Boeing are collaborating on the development of technologies that offer a solution to mobility challenges in contested environments and distributed military bases.
FIW technology integrates an embedded lift fan with a blended wing body design, enabling vertical lift without compromising the payload capacity and aerodynamic efficiency typical of modern fixed-wing aircraft.
Newly released renderings of the vertical lift concept show its scalability for use in airborne logistics and personnel recovery missions in areas without prepared runways.
Currently, the team is designing an uncrewed demonstrator with a 45-foot wingspan and a payload capacity of 1,000 pounds for the SPRINT program.
The propulsion system will incorporate off-the-shelf turbofan and turboshaft engines, allowing the vehicle to reach a maximum speed of 450 knots true airspeed (KTAS).
The SPRINT X-plane’s technology could eventually be scaled to medium and heavy-lift aircraft, forming a family of systems. Aurora envisions a manned aircraft with a 130-foot wingspan, four lift fans, and a 40-foot payload bay.
This FIW aircraft is projected to meet or exceed the payload, range, and speed capabilities of fixed-wing military transport aircraft while providing the tactical advantage of vertical takeoff and landing.
Newly released renderings of the vertical lift concept show its scalability for use in airborne logistics and personnel recovery missions in areas without prepared runways.
SPRINT Program Testing Events
Earlier in 2024, the team completed the first of three major test events planned for the current phase of the SPRINT program. The tests aim to validate the feasibility of FIW technology.
A ground effect test, conducted with a 4.6-foot wingspan model equipped with three lift fans, demonstrated that the suck-down effects produced by the lift fans during hover were minimal and that the landing gear height is optimized to prevent adverse pitching moments during ground operations.
Wind tunnel tests, scheduled for late 2024 and early 2025, will include a stability and control test using a 9-foot full wingspan model and a 5¼-foot semi-span embedded lift fan test to examine aerodynamic effects.
The current phase of the program is set to continue through May 2025, with a preliminary design review scheduled for April 2025. Flight testing for the SPRINT program is expected to take place in 2027.
Mike Caimona, president and CEO of Aurora Flight Sciences, commented, “The SPRINT program offers the opportunity to deliver a game-changing capability to the warfighter. High-speed, stealth, runway-independent transport could help keep warfighters safe and effective in contested environments, so no domain is out of reach for our U.S. military.”