Photograph of a Douglas C-1 aircraft (fuselage number 1) aerially refueling the "Question Mark," a U.S. Army Air Service Fokker C-2A aircraft, circa 1929.
Photograph of an aerial refueling procedure between a Douglas C-1 aircraft and the "Question Mark," a U.S. Army Air Service Fokker C-2A aircraft, circa 1929.
Photograph of a Douglas C-1 aircraft (fuselage number 1) aerially refueling the "Question Mark," a U.S. Army Air Service Fokker C-2A aircraft, circa 1929.
Photograph of a U.S. Army Air Service Curtiss P-6 Hawk aircraft (fuselage number 22), circa 1930.
Inscription on verso: "U.S. Army pursuit biplane / circa 1930."
Photograph of a captured Fokker D.VII aircraft (fuselage number U.10), circa 1918. The 95th Aero Squadron's "kicking mule" emblem is painted on the fuselage.