Tesla’s last patents from 1928 were protecting a new type of aircraft with vertical take-off and landing capability. The apparatus for aerial transport, or “helicopter-airplane”, as Nikola Tesla christened his invention was the crowning achievement of his research in aviation.

He planned to introduce a new method of vertical take-off aircraft, which would continue into a flight as a conventional airplane, and a new type of motor drive, based on his perfected turbine, which he considered suitable to replace conventional internal combustion motors.