Engineers at Bell have completed a wind tunnel testing campaign of a high speed vertical take-off and landing X-plane that features a Stop/Fold rotor system.
The concept is being developed for a DARPA program called the Speed and Runway Independent Technology (SPRINT) program and could form the basis of future high speed vertical take-off and landing (HSVTOL) aircraft used by the US military.
The wind tunnel testing, which was done at the National Institute for Aviation Research (NIAR) at Wichita State University, follows the successful evaluation of the Stop/Fold rotor system using the Holloman High Speed Test Track (HHSTT) in New Mexico, USA in 2023.
Bell said that the wind tunnel program validated the stability and control of the aircraft through the rotor fold and unfold sequence in flight, proving that the concept is ready to move ahead into flight demonstration for SPRINT.
Jason Hurst, executive vice president, engineering at Bell said, “After completing folding rotor transition testing on the sled at Holloman Air Force Base last year, we’re thrilled to have now completed this next phase of testing.
“Our Stop/Fold family of systems will revolutionize the speed, range and survivability of vertical lift aircraft to enable operations in contested environments. We are excited to be part of another aviation milestone with this breakthrough technology.
Bell is currently in Phase 1B of the DARPA SPRINT program. The SPRINT program intends to design, build and fly an experimental aircraft (X-Plane) to demonstrate enabling technologies and integrated concepts necessary for a transformational combination of aircraft speed and runway independence for the next generation of air mobility and air combat platforms.
The Stop/Fold configurations combine modern jet speed with runway independence. The ability to leverage available runways for maximum payload and range, along with robust vertical lift, will empower agile combat employment from nearly any location to deliver a clear strategic advantage, particularly in the Indo-Pacific theater, according to Bell.
