VTOL, stands for vertical take-off and landing, refers to an aircraft that is capable of hovering, take off, and land vertically.
The VTOL aircraft was first conceived and patented by Serb-American inventor Nikola Tesla in 1928. Further development on the VTOL was put on hold until 1935 when President Roosevelt's Works Progress Administration demanded a new, nimble aircraft with a high payload capacity. This led to the development of the UH-17 Atlas, based on Tesla's blueprints. However, the UH-17 was originally plagued by a number of incidents blamed on poorly-loaded cargoes, but actually caused by the VTOL descending into its own rotor wash; this problem was not properly fixed until 1937.
- VTOL on Wikipedia.