Wireless Air Force in WWI was mainly about observation and reconnaissance for ground forces. It also marked the start of what we now call Air Traffic Control. 

Radio got off the ground during World War I. For much of the war, small biplanes were weighed down with a 75 pound spark transmitter (see inset). Pilots had a Morse Code key strapped to their leg. They had to crank out a 150 foot wire antenna after taking off. When combat was required, the antenna was cut loose. All in all, not much fun. But by 1918, wireless air force became essential.

Before the war, engineers experimented with sending radio signals from non-rigid airships over a range of 35 miles. In 1912, the British War Office held a competition to select a suitable aircraft for Army reconnaissance and artillery spotting. By 1914, most artillery units had spotter aircraft equipped with wireless. Observers used a two-digit “clock code” to indicated the artillery distance and direction from target. One of the dangers faced by artillery spotting aircraft was being hit by their side. Typically the air observers flew at altitudes similar to the path of the artillery shells.

In addition to observation of artillery and troop movement, wireless equipped aircraft played a big role in reconnaissance, particularly tracking down enemy ships.

All in all, wireless in the air was more of a series of experiments than any master plan. Forces on both sides tried different things with the new technology. Some worked well, many did not. For example, no one thought about frequency coordination and there was lots of “friendly jamming”.

Wireless Air Force and More

During 1915, advances in tube technology led to smaller continuous wave transmitters replacing the spark devices. Then, Morse keys were replaced by microphones for radio telephony. The first use of air-to-air voice communications arrived in July 1917. Much of the cutting edge development took place at the Wireless Experimental Establishment at Biggin Hill. By the end of the war, some pilots were using full duplex voice communication during air combat.

Based on ideas from Nicholas Tesla, Britain developed the first unmanned drone, or UAV, in 1915. The “Aerial Target” was a radio controlled monoplane with explosive ordinance. It could be used to destroy enemy Zeppelins or bomb ground targets. The AT was deliberately misnamed to confuse spies about its real purpose. The radio control worked fine until the airplane motor was started and caused RF interference.

Technology advanced rapidly. By the end of WWI, U.S. Army Air Force was using the Western Electric SCR-68. This was a complete 5 tube voice transceiver operating on 750 kHz. Range was about 15 miles with output power of less than 1 watt. This device could also be integrated with the intercom system. It was powered by a wind driven generator. If you are interested, this article describes the set in detail; it was state of the art at the end of hostilities.