This is a Significant Technology milestone.
This was a machine designed by John Newton Williams for Emile Berliner.
The aircraft probably needed steadying from the ground and it is not clear if a true hover was ever established, or if this truly qualified as VTOL flight.
Note: Only the year of this milestone is known although it is known that it occurred pre May 1908.
Source: "The American Helicopter | An Overview of Helicopter Developments in America 1908-1999", Michael J. Hirschberg, July 2000, Page 4