Hangars at the North Island, San Diego, California airfield in 1912.   Aircraft shown is a Curtiss Model E (Left) and Curtiss Model G (Right).    Later known as Rockwell Field.
United States Army
Cameron, Rebecca Hancock, 1999, Training to Fly.  Military Flight Training 1907-1945   Air Force History and Museums Program, Air Force Historical Research Agency, Maxwell AFB, Alabama