The Avro 538 was a considerably modified development of the basic Avro 531 design with equal-span wings, normal wing strutting and a larger upper wing/fuselage gap.

Intended as a racing aircraft, the 538 was never used as such because of a defective spar. Powered by a 150 hp / 112 kW Bentley B.R.2, it was used by Avro Transport Co as a communication aircraft from May 1919 until September 1920.

Engine: 150 hp / 112 kW Bentley B.R.2
Wingspan: 8.53 m / 28 ft 0 in
Height: 2.59 m / 8 ft 6 in
Wing area: 19.51 sq.m / 210.0 sq ft
Empty weight: 442 kg / 975 lb
Take-off weight: 635 kg / 15400 lb
Range: 320 mi / 515 km

Circa 1928 Edmund T Allen, Salt Lake City UT. built a two-place open cockpit biplane, bowered by a 29hp Wright-Morehouse engine.

A home-built, undocumented other than mention that it was built in Utah, and its photo taken in Cheyenne.