WASHINGTON — March 9, 2026 : The U.S. Defense Advanced Research Projects Agency (DARPA) has formally designated its newest experimental aircraft as the X-76, marking the transition of the SPeed and Runway INdependent Technologies (SPRINT) program into the manufacturing phase. The aircraft is being built by Bell Textron Inc. following the successful completion of a Critical Design Review (CDR), a milestone that confirmed the design is ready for physical construction and system integration.
The SPRINT program is a joint effort between DARPA and the U.S. Special Operations Command (SOCOM) aimed at developing an aircraft capable of combining the high cruise speeds typically associated with fixed-wing jets with the vertical takeoff and landing (VTOL) capabilities of rotary-wing platforms. The initiative seeks to remove the long-standing requirement for prepared runways while preserving rapid long-distance mobility.
Program Background and Development Phases
The SPRINT program began in November 2023 with Phase 1, during which competing contractors conducted conceptual and preliminary design work. Two teams—Bell Textron and Aurora Flight Sciences—participated in the early stages of the program.
In May 2024, DARPA advanced both companies into Phase 1B to continue refining their concepts. After a competitive down-selection process, Bell Textron was chosen in July 2025 to proceed with Phase 2 of the program.
Under the Phase 2 and Phase 3 contract awarded in June 2025, Bell Textron is responsible for detailed engineering design, manufacturing of the X-plane demonstrator, integration of major subsystems, ground testing, certification activities, and preparation for the flight test campaign.
Following the recent Critical Design Review, Bell has now begun assembling the aircraft and integrating its propulsion and flight systems at company facilities. The program is moving through the manufacturing and ground testing phases, with the demonstrator expected to be completed in 2027.
Aircraft Design and Performance Goals
The X-76 demonstrator is intended to validate technologies that allow an aircraft to maintain high-speed cruise performance while remaining independent of runways. According to DARPA program objectives, the aircraft is being engineered to achieve cruise speeds between 400 and 450 knots (approximately 460–518 miles per hour or 740–833 kilometers per hour) at operational altitudes.
At the same time, the aircraft must be capable of hovering and operating from austere environments, including unprepared surfaces where conventional aircraft cannot operate. The design seeks to address the longstanding trade-off between the speed of fixed-wing aircraft and the operational flexibility of helicopters.
The Bell Textron concept incorporates a stop/fold rotor propulsion system. This configuration allows the aircraft to lift off vertically using rotor-based propulsion similar to a helicopter. Once airborne, the system transitions to forward flight, where the rotor mechanism can be stopped and folded, enabling efficient high-speed cruise similar to that of a jet-powered aircraft.
The design builds on Bell’s experience in tiltrotor development but introduces new mechanisms intended to improve speed, aerodynamic efficiency, and operational versatility.
Operational Objectives
The X-76 is being developed as a technology demonstrator rather than an operational aircraft. Its primary purpose is to test integrated systems and validate aerodynamic and propulsion concepts that could later be scaled into operational platforms.
DARPA and SOCOM are examining how such technologies could support a range of future military missions, including:
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infiltration and exfiltration of special operations forces
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contested personnel recovery
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troop transport and logistics support
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armed escort missions
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dispersed operations aligned with concepts such as Agile Combat Employment
According to U.S. Navy Commander Ian Higgins, the DARPA SPRINT program manager, traditional runways have historically served as both an operational advantage and a potential vulnerability for military aviation. Aircraft that can operate without prepared airstrips could enable rapid deployment and sustained operations in regions where runways are unavailable, damaged, or targeted during conflicts.
X-76 Naming and X-Plane Lineage
The aircraft’s “X-76” designation is intended to mark the upcoming 250th anniversary of the United States in 2026, referencing the year 1776. The designation also places the aircraft within the long-standing U.S. tradition of X-planes, experimental aircraft developed to explore new aerospace technologies and push the boundaries of flight performance.
X-plane programs historically focus on experimental capabilities rather than immediate operational deployment, with test data used to inform future aircraft development.
Funding and Program Status
For Fiscal Year 2026, DARPA has requested $55.2 million to continue advancing the SPRINT program. The funding is intended to support development of the demonstrator aircraft and reduce technical, schedule, and cost risks associated with future runway-independent high-speed vertical-lift systems.
While the program has released general performance goals and propulsion concepts, specific technical details—including aircraft dimensions, payload capacity, and full propulsion configuration—have not yet been publicly disclosed.
Flight Test Timeline
The X-76 demonstrator is currently progressing through manufacturing, system integration, and ground testing activities. According to program plans, initial flight testing is scheduled to begin in early 2028.
Data collected during the flight test campaign will help evaluate the feasibility of high-speed VTOL aircraft capable of operating without runways and will inform potential future acquisition decisions by SOCOM and other branches of the U.S. Armed Forces regarding next-generation vertical-lift capabilities.
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