This is a standard issue M1912/1917 United States Army Air Service uniform coat. This coat was worn by 2nd Lt. Howard H. Gleason during World War I. Lt. Gleason went overseas on May 20, 1918 and served with the 8th and 258th Aero Squadrons.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.