Photograph of Lieutenant Wallen piloting a U.S. Army Air Corps Douglas O-38 aircraft, circa 1930s. The "dagger and ace of spades" emblem of the 116th Observation Squadron is painted on the fuselage.Caption: "116 Obs Sqdn / H.D. 10 (7-10-35 pm) / Lt.…
Photograph of five U.S. Army Air Corps Douglas O-38 aircraft in flight over mountainous terrain, February 6, 1931. Caption: "(O38 92-P-115) (2-6-31) (12-4100)."