DARPA Unveils X-76 VTOL X-Plane
DARPA's high-speed VTOL program officially has a name: the X-76. Developed by Bell Textron, the SPRINT demonstrator will test radical tech for runway-independent flight, including fold-away rotors that transition to fixed-wing mode. The goal is to hit cruise speeds that rival conventional jets, creating a new class of aircraft.
The Speed and Runway Independent Technologies (SPRINT) program is a collaboration between DARPA and U.S. Special Operations Command. Its objective is to break the trade-off between the high speed of fixed-wing aircraft and the operational flexibility of VTOL platforms. The X-76 aims to achieve cruise speeds between 400 and 450 knots, a significant leap over the V-22 Osprey's top speed of 270 knots. Bell's winning design is built around its High-Speed Vertical Takeoff and Landing (HSVTOL) technology, which the company has been developing for over a decade. A key feature is the "stop/fold" rotor system, where the proprotors halt and fold away after transitioning to forward flight, reducing drag and allowing a separate jet propulsion system to take over for high-speed cruise. This innovation is central to reaching jet-like speeds. The X-76 designation is a deliberate nod to the year 1776, tying the experimental aircraft's revolutionary goals to the spirit of the American Revolution and the nation's upcoming 250th anniversary. The project has now passed its Critical Design Review, moving from design phases into manufacturing and assembly. The SPRINT program initially included four competitors in its first phase: Bell, Aurora Flight Sciences, Northrop Grumman, and Piasecki Aircraft Corp. The field was narrowed to Bell and the Boeing subsidiary Aurora Flight Sciences for a preliminary design competition, with Bell ultimately being selected in July 2025 to build the demonstrator. Aurora's concept was a blended-wing-body design with fan-in-wing lift systems. The program is structured in three phases, with Phase 2 focusing on the build and ground testing of the X-76 demonstrator. Flight testing is slated to begin in early 2028 as part of Phase 3. The technologies validated by the X-76 are intended to be scalable for a variety of future military aircraft.
