a flight delivery system that utilizes an architectural structure and network that allows real - time digital signals to be stored , retrieved and converted to an audio signal for radio transmission to achieve nearly instantaneous transmission of real - time data . the system utilizes a computerized reservation system as a source of information and stores it on a database . the information is called up by a computer that converts the data to a digital audio signal . the digital audio signal is then broadcast over airport antennae . the system features programs that allow for a conversion from airport city codes to the common identification for local cities .