Bell Textron Inc announced on 4 December 2024 that it has completed wind tunnel testing at the National Institute for Aviation Research (NIAR) at Wichita State University in support of the Defense Advanced Research Projects Agency’s (DARPA’s) Speed and Runway Independent Technology (SPRINT) programme.
This test phase follows successful evaluation of Bell Textron’s innovative ‘Stop/Fold’ rotor system using the Holloman High Speed Test Track (HHSTT) in New Mexico in 2023.
Building upon the previous folding rotor testing, the wind tunnel programme validated the stability and control of the aircraft through the rotor fold and unfold sequence in flight. Together, these two critical risk reduction tests prove the concept is ready to move ahead into a flight demonstration as part of the DARPA SPRINT programme.
“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,” Jason Hurst, executive vice president of engineering at Bell, was quoted as saying in a company press release. “Bell’s advanced Stop/Fold family of systems will revolutionise 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 programme, which 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.
Bell’s scalable Stop/Fold configurations combine modern jet speed with runway independence, which the company says will offer next-generation capabilities that will transform the battlefield. The ability to leverage available runways for maximum payload and range, along with robust vertical lift, allows agile combat employment (ACE) from nearly any location. This promises to deliver a clear strategic advantage, particularly in the Indo-Pacific theatre: an environment with limited runways, vast distances and a contested battlespace.
The technology is also ideally suited for special forces operations, where enhanced speed, reach and runway independence can make the most challenging and sensitive missions more survivable.
