This is a Notable Operational milestone.
This was the first time the full sequence from VTOL take-off to high speed horizontal flight and VTOL landing was completed. The aircraft was flown by Ryan's Chief Engineering test pilot Peter F. Girard. The first prototype had flown on 10 December 1955 from a horizontal take-off using a temporary landing gear arrangement.
See the AHS V/STOL Wheel entry for the aircraft for more details.
Source: Aviation Week & Space Technology, May 13, 1957, Page 29