On November 11, 1916, Capt. Charles deF. Chandler, a former balloonist, was relieved as Director of the Signal Corps School at Fort Leavenworth, and was ordered to Fort Omaha via Washington, to set up a balloon school.  He arrived in Omaha on 16 November (or so says the history; maybe it was December), and on 20 December, the organization was designated the US Army Balloon School.

My grandfather, Joseph S. Batt, was a balloon pilot (or rather, observer) in the Aviation Section of the Army Signal Corps during WWI.  After completing Officer Training at Camp Upton on Long Island in May, 1917, he attended the Balloon School Officers' Course at Fort Omaha, learning motors, gases, telephony and balloon construction, and presumably earning balloon pilots' wings.  He was shortly thereafter designated an Aerial Observer, and was an instructor in cordage on the Balloon School staff at Fort Omaha.  He apparently served as an inspector for the Army Bureau of Aircraft Production, assigned at the Connecticut Aircraft Company, a manufacturer of lighter-than-air ships at New Haven, Connecticut.  In July, 1918, as a second lieutenant, he was transferred to Camp John Wise, in San Antonio, where he was promoted and assigned as Officer In Charge of the Cordage and Fabric Schools and CO of the 68th Balloon Company.  He was discharged from active duty in March, 1919 and in August, 1919 was commissioned with the rank of first lieutenant in the reserves for 5 years.³
 
 

Radio was probably the other invention that allowed the forward air controller to actually work from above/ahead of the battlefield.  Observers in tethered balloons communicated via telephones.  Prior to the development of lightweight airborne radio transmitter-receiver sets, the aerial observer who spotted something had to fly back over "friendly" lines and drop message containers, putting a time lag between observation and fire direction.  It also made communications easier when radio technology went beyond the stage where aircraft had to communicate with morse code; Radiotelegraphy did get through more reliably, with lower power requirements than radiotelephony, and it was widely used for aircraft communications well into World War II (and continued to be the mode of choice at times, up through the Korean War period).  Also, through the 1950s, aircraft radios were limited by the need for a resonant crystal for each discrete frequency to be used.  Modern FACs were fortunate to be able to simply dial in any required freq to talk with air traffic control, command posts, strike flights or friendly units.