Sikorsky has flight-tested the control laws for its rotor-blown wing drone in helicopter and fixed-wing modes.
The battery-powered 115 lbs (52kg) twin prop-rotor prototype drone has been flying stably and performing maneuvers across all flight regimes during flight tests. Sikorsky said the success of the testing opens up the possibility of scaling up the vertical take-off and landing (VTOL) design to larger sizes and combining it with hybrid-electric propulsion systems.
Rich Benton, vice president and general manager at Sikorsky said, “Combining helicopter and airplane flight characteristics onto a flying wing reflects Sikorsky’s drive to innovate next-generation VTOL UAS [unmanned aerial systems] that can fly faster and farther than traditional helicopters.
The company’s R&D unit, Sikorsky Innovations, developed and tested the rotor-blown wing design in a year. The drone has progressed through preliminary design, simulation, tethered and untethered flight to gather aerodynamic, flight control, and quality data.
A key milestone was achieved in January when the 10.3ft composite wingspan aircraft completed more than 40 take-offs and landings. The aircraft has performed 30 transitions between helicopter and airplane modes, the most complex maneuver demanded of the design.
In horizontal flight mode, the aircraft reached a top cruise speed of 86 knots. Engineers are also performing wind tunnel tests on a 1:1 scale model to validate the newly developed control laws by correlating them with real-world experimental data.
“Our rotor-blown wing has demonstrated the control power and handling qualities necessary to transition repeatedly and predictably from a hover to high-speed wing-borne cruise flight, and back again,” said Sikorsky Innovations Director Igor Cherepinsky. “New control laws were required for this transition maneuver to work seamlessly and efficiently. The data indicates we can operate from pitching ships decks and unprepared ground when scaled to much larger sizes.”
Sikorsky said potential applications of the rotor-blown wing drone include search and rescue, firefighting monitoring, humanitarian response, and pipeline surveilling. Larger variants could fulfil long range intelligence, surveillance and reconnaissance missions, and piloted drone teaming (crewed/uncrewed teaming) missions it added.
Other drones Sikorsky is developing include a winged VTOL UAS and single main rotor aircraft and a 1.2MW hybrid-electric demonstrator (HEX) configured with a tilt wing and a fuselage to carry passengers or cargo across long distances. A HEX power system test bed is expected to demonstrate hover capability in 2027.
