The Sparrow I was designed and built for the 1924 Lympne light aircraft trials. It was a two-seat biplane powered by a 35 hp (26 kW) Blackburne Thrush piston engine, with dual controls. The Sparrow I (registered G-EBJP) first flew on 11 September 1924. The Thrush, a three-cylinder radial engine proved to be extremely unreliable and the Sparrow was eliminated from the light aircraft trial due to engine failure. In the Grosvenor Trophy Race at Lympne Aerodrome on 14 October 1924, it came fourth with a speed of 62.08 mph (99.91 km/h).
The aircraft was rebuilt for the 1926 Lympne Trials as a parasol monoplane (and redesignated the Sparrow II) and re-engined with a 32 hp (24 kW) Bristol Cherub III engine. During the trials the Sparrow force-landed near Beachy Head on 12 September 1926, again being eliminated from the competition, which was won by the Hawker Cygnet. After use for testing wing sections, the aircraft was sold to the Halton Aero Club, remaining in existence until 1933.