Flight in which an airplane transitions from subsonic speed to a
speed at or beyond the speed of sound. Transonic flight is
considered to be between about 600 and 900 miles per hour, or mach
0.8 to Mach 1.2.
Source: Patrick Forrey, president of the
National Air Traffic Controllers Association. The union asserts
staffing shortages in control facilities throughout the nation are
to blame for a sizable number of airline flight delays -- and
disputes claims by the FAA and airlines the solution to control
problems lies in adoption of the highly publicized "NextGen" air
traffic control system.