Hoover was slated to fly the X-1 flight, but did something to get himself in trouble. Yeager got the honor instead
Yeager was always the nominated pilot, Hoover was the backup. Perhaps if the fact that Yeager had two broken ribs and in considerable pain had become known he may have been grounded and the flight would then have been Hoovers. Hoover was on the program because Yeager had requested so, along with Jack Ridley, who rather than being given a piloting role was assigned as flight test engineer. Hoover never got to fly the aircraft but Ridley did a number of times. One month after the supersonic flight where Hoover flew chase he had an accident in an F-84 where a fire burnt through the control runs, the ejection seat failed so he jumped where he was slammed into the tail, broke a leg and a few other bones, following a protracted convalescence his spot in the X-1 program had already been filled.