The 1929 single-place Helicopter used a helical vane arrangement with a myriad of wires replacing the wings and stabilizers on a heavily-modified Curtiss JN-4D fuselage. US patent #1,694,880 was granted in 1928. The rotor was driven by a disc drive, with friction providing speed control.
The plane was apparently built, but flight info, if any, was unrecorded.
Engine: 150hp Hisso A
Rotor: 26’0″
All Aero 