First tandem rotor helicopter flight (Cornu 1907 machine)

Description

The aircraft was the Cornu 1907 machine. It is not clear though whether this machine ever truly attained controlled flight in any sense (see Cornu's Helicopter - First in Flight, Professor J. Gordon Leishman, VERTIFLITE Fall/Winter 2001, Page 54), but it does represent the first attempt to use a longitudinal tandem configuration for a rotorcraft.

Source: "The American Helicopter | An Overview of Helicopter Developments in America 1908-1999", Michael J. Hirschberg, July 2000, Page 3