This is a Notable Operational milestone.
First flight of the Sikorsky entry for the US Army UTTAS (Utility Tactical Transport Aircraft System) competition. The aircraft registration was 73-21651.
The pilots were Dick Wright (Sikorsky Chief Test Pilot) and John Dixson (UTTAS Chief Test Pilot) (see "Blackhawk: The Story of a World Class Helicopter", Ray D. Leoni, Published by American Institute of Aeronautics and Astronautics, 2007, ISBN-13: 978-1-56347-918-2 - this information is reprinted by permission of the American Institute of Aeronautics and Astronautics, Inc.).
The second prototype flew on Jan 21, 1975 after extensive modifications.