Santos-Dumont No.12


Drawings of the No.12 appeared in 1905 with two tandem counter-rotating rotors and a single tractor propeller at the front. Victor Tatin assisted in the design of the the propellers, which were constructed of steel tubes and fabric, and weighed less than 9kg each. The 24hp Antoinette V8 engine was tested with the 3 propellers and found inadequate. The helicopter was not completed.