 The 115 AS is the oldest unit in the California Air National Guard, having almost 90 years of service to the state and nation.It is a descendant organization of the World War I 115th Aero Squadron, established on 28 August 1917.It was reformed on 16 June 1924, as the 115th Observation Squadron, and is one of the 29 original National Guard Observation Squadrons of the United States Army National Guard formed before World War II.