Bell advances in DARPA SPRINT X-plane program with VTOL demonstrator

Bell Textron has been selected by the US Defense Advanced Research Projects Agency (DARPA) for Phase 2 of the Speed and Runway Independent Technologies (SPRINT) X-plane program.  

The initiative aims to develop a next-generation high-speed vertical takeoff and landing (VTOL) aircraft capable of operating from unprepared surfaces while reaching speeds of 400 to 450 knots (740–830 kilometers per hour). 

Bell confirmed the down-selection on July 9, 2025, now tasked to complete the detailed design, construction, and ground testing of a demonstrator aircraft, culminating in flight testing under Phase 3. The announcement also marks the elimination of Aurora Flight Sciences, a Boeing subsidiary, from the competition. 

Bell banks on ‘stop/fold’ rotor design 

“Bell is honored to have been selected for the next phase of DARPA’s SPRINT program and is excited to demonstrate a brand-new aircraft with the first-ever stop/fold technology,” said Jason Hurst, Senior Vice President of Engineering at Bell. “This is an achievement we’ve been working towards for over 10 years.” 

During Phase 1, Bell completed conceptual and preliminary design work for its SPRINT X-plane. The company has also carried out extensive risk-reduction activities, including folding rotor demonstrations, integrated propulsion testing, and wind tunnel trials at Wichita State University’s National Institute for Aviation Research (NIAR). 

Bell’s proposal reportedly incorporates its patented stop/fold rotor system, allowing the aircraft to switch from rotor-borne hover to efficient fixed-wing forward flight—building on decades of Bell VTOL innovations including the X-14, XV-3, XV-15, and the groundbreaking Bell X-1. 

Aurora’s concept exits the competition 

Aurora Flight Sciences had been developing a competing high-speed VTOL concept using embedded lift fans and a blended wing body configuration. In April 2025, the company announced that a 20% scale model had completed wind tunnel testing at a Boeing facility near Philadelphia. 

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While Aurora said the test validated its performance predictions and was a “key milestone,” the concept did not move forward in DARPA’s selection. The post Bell advances in DARPA SPRINT X-plane program with VTOL demonstrator appeared first on AeroTime.

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