On September 9, 1928, Oszkár Asbóth took off vertically with his helicopter powered by a 120 HP nine-cylinder engine and propelled by two wooden propellers, each 4.35 meter in diameter, placed parallel above each other and rotating in opposite direction. Tires were replaced by four footballs to provide sufficient flexibility for landing. During the first flight, after 1100 rotations the plane swiftly took off, at ten meters stopped, hovered for some ten minutes, remained absolutely stable around all axes, than smoothly descended.
The two large wooden propellers raised Asbóth´s device into the air together with its pilot more than 200 times and hovered in the air for almost one hour, which was a great achievement, but because of their rigid propellers Absóth´s „helicopters" became unstable when moving forward or when subjected to a strong side wind.
By his good business sense Absóth was able to profit from his inventions. The British Air Ministry got an option of purchase of his helicopter in 1938.