A technician straps test pilot Scott Crossfield into the cockpit of the X-15 rocket plane before an early test flight. (NASA/North American Aviation photo) On June 8, 1959, a sleek black rocket plane was carried aloft beneath the wing of a B-52 from NASA's Flight Research Center (now NASA Dryden) at Edwards Air Force Base, Calif., with North American Aviation test pilot Scott Crossfield at the controls. The milestone flight began nearly a decade of flight research that probed the hypersonic speed realm and altitudes at the edge of space. NASA / Photo
For the maiden flight, Crossfield – who had helped design the airplane – planned to execute an unpowered glide in order to verify the X-15's basic handling qualities. He noticed that his pitch damper was inoperative but elected to continue with the mission since the flight plan involved little risk.
Following release from the B-52, all went well until Crossfield attempted to reduce the steepness of his final approach to the runway on Rogers Dry Lake and suddenly found himself the victim of a pilot-induced oscillation. Observers watched in horror as the X-15 dropped toward the ground while its pitching motion increased in amplitude. Crossfield managed a smooth – if hard – landing, damaging the landing gear but saving the aircraft.
One of the three X-15 rocket planes drops away from its B-52 launch aircraft during an early research flight. (NASA photo) That first glide flight was the first in a series of contractor demonstration flights flown by Crossfield. The second flight, on Sept. 17, 1959, was the first powered X-15 flight.
The X-15 rocket plane is often called the most successful research aircraft ever built. Three were built, flying 199 times over a span of nearly 10 years. They exceeded their design specifications, set numerous official and unofficial speed and altitude records, and yielded a treasure trove of data later used by engineers designing future aerospace vehicles.