The 1920 civil aeroplane competition[1][2] emphasised safety in terms of a short takeoff and slow landing speed as well as useful load and economy.

The single passenger was enclosed in a cabin immediately behind the pilot's open cockpit, with a raised roof and windows in the decking where the second seat in the Tourer had been.

For the competition, it was powered by a water-cooled upright inline 240 hp (180 kW) Siddeley Puma with a large nose radiator behind the wooden two-blade propeller.

[3] After the competition, Bristol retained the Seely for general duties until 1923, when it was converted into a testbed for Jupiter development, being purchased by the Air Ministry for use with the Royal Aircraft Establishment.

It was fitted with a 435 hp (324 kW) Jupiter III nine-cylinder radial engine driving a steel two-bladed Leitner-Watts propeller.