The Type E biplane was designed in parallel with the slightly earlier Avro Duigan, differing principally in being slightly larger and having a more powerful () water-cooled E.N.V. engine. Both were two-bay tractor biplanes with unstaggered parallel-chord wings with rounded tips, a deep rectangular section fuselage bearing a rectangular steel-framed stabiliser, elevator and rudder with no fixed fin, and a tidy undercarriage with a pair of wheels on a transverse leaf-spring and a long central skid projecting forward of the propeller. This unremarkable description is of a remarkable aircraft. This aircraft layout dominated aircraft design for twenty years: the Avro 500 and the contemporary B.E.1 are among the first truly practical examples built.