First conversion from a stationary wing to a rotating wing in flight (Herrick HV-2A)
Saturday, July 24, 1937
- Boulevard Airport, PA, United States of America 
This is a Notable Technology milestone.
Description:
This was the first time that an aircraft had taken off with a stationary second wing, which was then allowed to rotate in forward flight
The aircraft was a Herrick HV-2A Convertaplane, piloted by George Townson, operating out of Boulevard Airport, PA.
Demonstrations of this capability were made to the public on 30 July.
Source: "American Autogiro, Gyroplane and Early Convertaplane Developments", Agnew E. Larsen, Journal of the American Helicopter Society, Vol. 1, No. 1, January 1956, Page 14).
