The earliest attempt to use the Magnus effect for a heavier-than-air aircraft was in 1910 by a US member of Congress, Butler Ames of Massachusetts.
This seaplane was built for Zaparka in 1930 and was reported to have made successful flights over Long Island Sound.
A Flettner rotor is a smooth cylinder with disc end plates which is spun along its long axis and, as air passes at right angles across it, the Magnus effect causes an aerodynamic force to be generated in the third dimension
An inherent safety concern is that if power to the rotating drums was lost—even if thrust was maintained—the aircraft would lose its ability to generate lift as the drum slowed down and it would not be able to sustain flight.
Only RC models using this method exist today
Popular Science Monthly: 26. November 1930