[1][2][3] The OK-15 was a light sports monoplane of conventional design with a low wing, enclosed side-by-side two-seat cockpit and fixed undercarriage with tailwheel.
It was manufactured using traditional materials of metal, wood and fabric, and stressed for aerobatics.
The aircraft was powered by a 105 horsepower (78 kW) Walter Minor 4-III piston engine, giving it an estimated cruise speed of 202 km/h (126 mph; 109 kn).
Subsequent fight tests showed its handling to be unsatisfactory and it was not put into production.
[5][4] Data from Österreichs Luftfahrt in Einzeldarstellungen: Propeller-Luftfahrzeugkonstruktionen seit 1945,[4] Jane's All the World's Aircraft 1958-59.