01 Boeing 40B-960

When the Post Office held a contest in 1925 for a new mail carrier, Boeing entered the Model 40, a biplane with a fuselage of wood and steel tube. The four-passenger model, 40B-4, was built four years later and bought by United soon thereafter. Length: 33' 2 1/4". Wingspan: 44' 2 1/4". Maximum speed: 128 mph.