The Elytron 2S tiltrotor, Short Take-off and Landing (STOL), demonstrator airframe completed and the company is planing flight tests later this year.
Images credit Elytron Aircraft
The 28-ft (8.5-m) wingspan Elytron 2S tiltrotor, combines rotorcraft and features of fixed-wing and is capable of Short Take-off and Landing (STOL).
The Elytron design combines three sets of wings: one pair of rotary wings called “proprotors”, mounted on a single tilt-wing in central position, and two pairs of fixed wings. The fixed wings are split into a forward pair and an aft pair that are joined by winglets, which make use of the joined-wing concept. By splitting the wings apart, the design eliminates any interference with the thrust of the proprotors. The main wings have a high aspect ratio, are braced and can be built very light which reduces drag. Since the front and rear wings are joined together by winglets, they enclose the proprotors eliminating the risk of rotor strikes. The plane has superior glide ratios and low stall speeds because of this low wing loading design, and also displays excellent Short Take-off and Landing (STOL) capabilities.
source Elytron Aircraft