Professor B.N.Yurjev was one of the leading Soviet helicopter theorists.
His works at this field date back to 1909. He initialized and conducted the
special helicopter group within TsAGI (Central Aero-Hydrodynamic
Institute) in 1926.
In 1946 B.N.Yurjev's design group completed the project of the vertical
take-off/landing (VTOL) experimental aircraft called KIT-1. This plane was
to be powered by one piston Klimov VK-108 engine, housed mid-fuselage
behind the cockpit, which turned two propellers located in the nose. The
forward one (3.6m in diameter) was the main one, which propelled the plane
during the whole flight, while the rear one (8m in diameter) was activated
only while take-off and landing and served as a helicopter rotor to provide
main portion of lift to the machine. In horizontal flight the rear rotor blades
were feathered and served as additional canard flying surfaces.
The project never left the drawing board, because there were no conditions
for success at that time. It certainly has many lacks and many disputable
points. But still it remains the unique technical design, intended to solve the
problems of the vertical take-off/landing, which were successfully solved in
American XFY-1 and XFV-1 planes a decade later.