The Waco E series is a small family of American-built cabin biplanes built between 1939 and 1942, which differed primarily by engine installation.

First flown in 1939, it had a much slimmer and more streamlined fuselage than earlier Waco C and S models and heavily staggered unequal-span parallel-chord wings with rounded tips.

[3] Engines varied in power from 285 to 450 hp (213 to 336 kW), giving the E series a high cruising speed for the period of up to 195 mph (314 km/h).

Note: the Waco GXE of 1929/30 was an unrelated biplane design with non-staggered wings The E series was sold to wealthier private pilot owners who required the comfort of a fully enclosed cabin and a high cruising speed, combined with a longer range.

Because of the type's good performance, 15 examples were impressed by the United States Army Air Forces during World War II for communications work as the UC-72.