Don’t what the occasion was, but some event of note brought this group of pilots together in the 1930’s. Center is Lewis Brereton, later a Lieutenant General. Brereton has the distinction of being the only officer to consecutively serve in the USAF and all its progenitors: The Aeronautical Division, Signal Corps. Aviation Section, Signal Corps – Air Service – Army Air Corps – Army Air Forces – US Air Force.
Other notables are in this photo as well, including George “Bill” Holloman, namesake of the Air Force Base. It is also noteworthy that two enlisted pilots are in this photo, Colby and Rosenberg.