S-9 'Kruglyj' (The Rounded One), I.I.Sikorsky
First monocoque monoplane built in Russia. Plywood skin thickness was 5mm on nose section and 3mm on the tail. Rectangular wings had aerodynamically clean joints with fuselage. Despite advanced design, aircraft was overweight and almost all dimensions were larger than in the project. In addition the engine provided only 80% of its nominal power. All this resulted in quite poor performance, and after few test flights S-9 was abandoned.
|Engines||1*100hp Gnome Monosaupape|
|Maximum Speed||less than 100km/h|