Lockheed Martin company Sikorsky has piloted its rotor blown wing uncrewed aerial system (UAS) in both helicopter and airplane configurations, confirming the successful application of advanced control laws.
The twin prop-rotor prototype, weighing 115lb and powered by batteries, offers stability and manoeuvrability across all flight regimes.
Sikorsky notes that the system indicates the potential to upscale the vertical take-off and landing (VTOL) design for larger, hybrid-electric models.
The rotor blown wing design is part of a broader range of systems under development by Sikorsky, which will include winged VTOL UAS and single main rotor aircraft.
The VTOL UAS is designed to take off and land vertically, resting on its tail like a helicopter, before transitioning to horizontal flight for longer missions.
The rapid prototyping division, Sikorsky Innovations, is spearheading the development of the rotor blown wing concept.
In a little over one year, the team has advanced from preliminary design and simulation to both tethered and free flight, collecting valuable data on aerodynamics, flight control, and performance quality.
Sikorsky Innovations director Igor Cherepinsky said: “Our rotor blown wing has demonstrated the control power and unique handling qualities necessary to transition repeatedly and predictably from a hover to high-speed wing-borne cruise flight, and back again.
“New control laws were required for this transition manoeuvre to work seamlessly and efficiently. The data indicates we can operate from pitching ships decks and unprepared ground when scaled to much larger sizes.”
A notable breakthrough is said to have occurred in January 2025 when the prototype, featuring a 10.3ft composite wingspan, completed more than 40 take-offs and landings.
The aircraft also executed 30 transitions between helicopter and airplane modes, the most intricate manoeuvre required by the design.
During horizontal flight, the aircraft attained a maximum cruise speed of 86 knots.
Concurrent wind tunnel testing on a full-scale model provided critical validation for the newly developed control laws, aligning them with empirical data from real-world experiments.
The future applications for UAS with rotor blown wing technology are diverse, encompassing search and rescue, firefighting operations, humanitarian efforts, and pipeline surveillance.
Larger versions of these aircraft are expected to facilitate extended-range intelligence, surveillance, reconnaissance missions, and facilitate crewed-uncrewed teaming operations.
All variants will incorporate Sikorsky’s MATRIX flight autonomy system to guide the aircraft autonomously.
Sikorsky is also working on a 1.2MW hybrid-electric demonstrator (HEX) with a tilt wing and a fuselage that can transport passengers or cargo over long distances.
A HEX power system test bed is anticipated to showcase hover capabilities in 2027.
