Air-to-ground communication

Since then, transponders have enabled pilots and controllers to identify planes automatically, greatly improving air security.

Ground crews would rely on colored paddles, hand signs and other visual aids.

In the beginning of World War I planes were not outfitted with radios, so soldiers used large panel cut outs to distinguish friendly forces.

These cut outs could also be used as a directional device to help pilots navigate back to friendly airfields.

James brought the science of wireless in aircraft to a high state of efficiency before he was shot down and killed by anti-aircraft fire on 13 July 1915.

[2][3][4] In early 1916 the Marconi Company (England) started production of air-to-ground radio transmitters/receivers which were used in the war over France.

[5] In May 1917, General George Squier of the U.S. Army Signal Corps contacted AT&T to develop an air-to-ground radio with a range of 2,000 yards.

[6] Following World War I new technology was developed to increase the range and performance of the radios being used to communicate with planes in the air.

Radar could be used to track planes in the air and determine distance, direction, speed and even type of aircraft.

The Royal Air Force used the R1155/T1154 receiver/transmitter combination in most of its larger aircraft, particularly the Avro Lancaster and Short Sunderland.

The transponder acts as an identification tool for aircraft allowing ATC towers to immediately recognize the identity of each plane.

The transponder alerted by the radar responds by sending a signal of its own back to the Tower, which identifies the aircraft.

Today Air-to Ground communication has evolved to the point where pilots no longer need to be in the plane to fly it.

They can be controlled by pilots thousands of miles away and can safely navigate treacherous terrain using ground mapping radars.