The De Havilland DH-4 served longer than any other World War I-era aircraft and was the most likely aircraft to be seen at any American airfield in the 1920s. A work-horse aircraft during the war, this extremely versitile plane was modified into numerous variations after the war.

The Douglas O-2 observation plane was the first of many O-series aircraft that succeeded the De Havilland DH-4 in the U. S. military. The redesigned fuselage and tail, streamlined carraige, and staggered wings of unequal length gave the O-2H model, shown here, an innovative advantage. The O-2 and the even more streamlined O-25 were common sites at Crissy Field in the late 1920s and early 1930s.