Aviation at Fort Sill added lighter-than-air ships to its inventory when Company A, 1st Balloon Squadron, arrived on 5 September 1917 from the Balloon School in Omaha, Nebraska. The company split to form the 25th and 26th Balloon Companies on 16 February and 2 April 1918. In order to meet the demand for trained aerial observers for field artillery, a Balloon Corps Training School was set up at Post Field in 1918. During World War I, the school trained 751 officers and created 89 companies, of which 33 were deployed to Europe.