On this day, in 1916, the first air to air radio communication between aircraft took place. The plane was U.S. Army's "No. 50"" piloted by Lt. A. D. Smith and U.S. Army "No 51" piloted by Lt. Dargue. The message was part of an ongoing effort lead by the U.S. Army's Cpt. C. C. Culver and involved aircraft that had been involved in radio experimentation. The message, "North Island makes new world record" was written by California Congressman Kettner. The aircraft were two miles apart and less than 1,000 feet in the air.
The event was more significant than it might now seem.
The U.S. air fleet itself was minuscule at the time and, given the rapid development of aircraft due to the war in Europe, it lagged behind technologically. It was deployed in the effort in Mexico, where the limitations of the aircraft had demonstrated themselves. Like aircraft everywhere in military use, the scouting role and potential of the airplane was evident, but like the cavalry that it was seeking to augment in this role, delivery of information obtained in the air was largely by direct word of mouth. Faster, obviously, than cavalry in these regards, it still wasn't instant.
Cpt. Cluver had been working on this situation as early as 1910, remarkably early, and was responsible for an Army effort that was studying "wireless" and aircraft. In that year, his efforts yielded the first ground to air radio communication. In 1915 he was billeted to the Army aviation school in San Diego California to continue to pursue his efforts, which included designing purpose built radios for aircraft.
Culver, then a Colonel, in 1918.
While radio had obvious application to aircraft, in all sorts of ways, and indeed would revolutionize much about flying, including military flying, advancements did not come rapidly enough to really see the new technology used much during the Great War. Some use was made, and at least the British experimented with some air to ground communication in a scouting and artillery spotting role. But, while the technology was developed, it didn't develop rapidly enough to really come into practical use to a great extent until after the war.