 In 1945, Reaction Motors, Inc. was granted a contract from the United States Army to develop a rocket engine for the first of the "X" series of experimental airplanes, designed to break the sound barrier.Undaunted by the 1946 death of British test pilot Geoffrey de Havilland Jr., the company eventually furnished the X-1 project with a design based upon four of Wyld's engines which would provide 1,500 pounds of thrust each.On October 14, 1947, American test pilot Chuck Yeager was the first in the world to break the sound barrier, piloting the X-1 with the four Reaction Motors, Inc. engines.