Abridgment of air transport communication

The successful operation of an air transportation system depends in no small degree on the communication facilities at its command. Rapid and dependable communication between transport planes in flight and the ground is essential. Two-way radio telephony provides this necessary plane-to-ground contact. The design of a radio telephone system for this service requires quantitative knowledge of the transmission conditions encountered in plane-to-ground communication. An experimental investigation of these conditions over the available frequency range has been carried out and the results are described. A complete aircraft radio telephone system designed for the use of air transport lines and an airplane radio receiver designed for reception of government radio aids to air navigation are also described.