Bell’s High-Speed VTOL Aircraft to Lead Phase 2 of DARPA’s SPRINT X-Plane

Bell Textron Inc., a subsidiary of Textron Inc., has been selected to advance to Phase 2 of the Defense Advanced Research Projects Agency (DARPA) Speed and Runway Independent Technologies (SPRINT) X-Plane program. This development marks a continuation of Bell’s involvement in DARPA’s initiative to explore high-speed vertical takeoff and landing (VTOL) aircraft capable of operating in austere environments without reliance on traditional runways.

SPRINT X-Plane. bellflight

The SPRINT program, launched in 2022, is a joint effort between DARPA and U.S. Special Operations Command. Its objective is to design, build, and fly an experimental X-plane that demonstrates a combination of high-speed cruise capability—targeting speeds between 400 and 450 knots—and runway independence. These characteristics are intended to address operational challenges in contested and distributed environments, where conventional airstrips may be unavailable or compromised.

Bell’s selection for Phase 2 follows its completion of conceptual and preliminary design work during Phases 1A and 1B. In the current phase, the company will focus on detailed design, construction, ground testing, and certification of the X-plane demonstrator. Flight testing is scheduled for Phase 3, which will evaluate the aircraft’s performance and validate its technological innovations.

Central to Bell’s design is the implementation of a stop/fold rotor system. This configuration allows the rotors to cease rotation and retract during flight, enabling transition to jet-powered cruise. The concept differs from traditional tiltrotor or short takeoff and vertical landing (STOVL) systems by aiming to reduce aerodynamic drag and enhance efficiency at high speeds, while retaining vertical lift capabilities for takeoff and landing in unprepared locations.

Bell has conducted extensive risk-reduction activities to support the development of this technology. These include testing of folding rotor mechanisms, integrated propulsion systems, and advanced flight control technologies at Holloman Air Force Base. Additional wind tunnel evaluations were performed at the National Institute for Aviation Research (NIAR) at Wichita State University to assess aerodynamic stability and control during transition phases between hover and cruise.

The company’s approach reflects a broader trend in military aviation toward platforms that combine the agility of helicopters with the speed and range of fixed-wing aircraft. In strategic contexts such as the Indo-Pacific region, where infrastructure may be limited and mobility is critical, such aircraft could support Agile Combat Employment (ACE) strategies by enabling rapid deployment and flexible operations.

Bell’s legacy in VTOL experimentation includes previous programs such as the XV-3, XV-15, and V-280 Valor, as well as the historic Bell X-1, the first aircraft to break the sound barrier. The current X-plane project builds on this foundation, incorporating lessons from past efforts while introducing new design elements tailored to emerging operational requirements.

The SPRINT program’s emphasis on scalability also suggests potential applications beyond the demonstrator phase. Bell’s renderings indicate that the aircraft could be adapted for both crewed and uncrewed missions, with roles ranging from logistics and surveillance to special operations. The modular nature of the design may facilitate integration into future air mobility frameworks, depending on the outcomes of flight testing and further development.

As Phase 2 progresses, Bell will continue refining its design and preparing for the transition to flight trials. The results of this phase will likely influence the trajectory of high-speed VTOL technology and inform future procurement decisions by defense agencies seeking versatile air platforms for complex operational environments.