Air traffic controllers use real-time tracking of all commercial aircraft. Private aircraft make use of local traffic control towers when they are available but are not always tracked by air traffic controllers.
All commercial aircraft pilots must file a flight plan prior to departure. The flight plan includes the airline name and flight number, the type of aircraft and equipment, intended airspeed and cruising altitude, and the flight route. The flight data person then reviews this flight plan. If it is approved, the pilot can proceed with normal take-off procedures. Before the flight takes off, the flight data person passes the plan along to the air traffic controllers along the flight path.