This is a Momentous Operational milestone.
The first 'free' flight of a VTOL aircraft configured as a helicopter that was capable of controlled flight in all axes. The first flight was piloted by Ewal Rohlfs from Bremen Airport (now an AHS/AIAA historic site).
The aircraft was a Focke-Wulf Fw 61/Focke-Achgelis Fa 61 (D-EBVU). Note that the propeller only provided cooling for the engine, rather than thrust in forward flight.
Source: "Vertical Flight Historic Aerospace Sites", AHS web site page, last updated March 18 2015