PAO "Yakovlev" has patented a drone design with a hybrid propulsion system that allows the lift propellers to be retracted from the oncoming flow after vertical takeoff. Leading design engineer Rail Gareev explained what problem this scheme solves.
Aircraft with separate propeller-motor groups for vertical takeoff and landing have a known drawback – after transitioning to horizontal flight, the propellers no longer contribute to movement but continue to create drag.
Technical solutions are aimed at increasing the range and speed of the unmanned aerial vehicle by reducing aerodynamic drag by 20–30% and optimizing energy resources.
According to "Yakovlev"'s concept, the front propeller-motor groups are placed inside special niches in the fuselage and, after transitioning to horizontal flight, are covered by aerodynamic flaps.
The rear lift propellers rotate along the oncoming flow and are also retracted under the flaps.