The Belyayev / Yemelyanov experimental sickle-wing glider (Russian: Беляев / Емельянов Планер с серповидным крылом) was developed at TsAGI in 1937 by VN Belyayev and VI Yemelyanov and never had a proper name, which is why it is known by its wing shape.
A new curved wing concept was tested on this glider, developed by Belyayev and tested on a Yemelyanov- built glider fuselage.
This glider was designed as a high-wing cantilever monoplane. The wing had a curved sickle shape, later be known as “Uprugoye Krylo” (elastic wing) or popularly as a “butterfly” wing. Long flaps were located on the trailing edge to improve the glider’s landing characteristics. The slim double-section ailerons were located along the entire span of the positive-taper section of the wing.
The elongated fuselage ended in a monoplane tail with stabilizers installed with a large angle of attack. The rudder featured a rounded trailing edge. The experimental glider was a two-seater with tandem enclosed cockpits.
This experimental model was completed in 1937 and during testing, when pulling out of a dive, the fore area was detached from the rest of the glider. The rupture occurred right by the second cabin, so that Alexandrov was suddenly in the air. Rastorguyev circled the falling cockpit several times before breaking free and launching himself into the void.
The pilot VL Rastorguyev and the experimenter VS Alexandrov, managed to save themselves by parachuting, but the glider was totally destroyed.
All Aero 