Although ordered into production before the aircraft first flew, it did not enter large scale service with the RAF owing to unreliable engines.

This was a radial engine under development which was meant to deliver 340 hp (254 kW) while weighing only 600 lb (272 kg), and on the basis of the promised performance, was ordered into production in large numbers.

The K-151 was further converted to a two-seater with a new cockpit fitted forward of the pilot's position and was sent to India and Malaya in 1920 for a series of sales-promotion flights.

[7] A new civil Nighthawk, registered G-EAJY, again modified to a two-seater, had its wingspan reduced by two ft and was flown at the 1920 Aerial Derby where it placed fourth at an average speed of 132.67 mph (213.51 km/h).

A much-modified Nighthawk appeared in 1920, designated the Goshawk with the aircraft incorporating a more streamlined fuselage, rounded tips on the upper wings and a tightly cowled engine installation.

Nieuport & General closed down in August 1920, and the rights to the Nighthawk were purchased by the Gloster Aircraft Company, who also hired Folland as chief designer.

Powered by a 450 hp (336 kW) Napier Lion II engine, this used a Nighthawk undercarriage, rear fuselage and tail with new, single-bay wings,[10] first flying on 20 June 1921.

[17] The Mars I, after conversion to the Gloster I, was fitted with floats and used as a training seaplane for the British 1925 and 1927 Schneider Trophy teams, remaining in use until 1930.

[16] The Gloster Sparrowhawk (or Mars II, III and IV) was a naval fighter for Japan, powered by the Bentley BR2 rotary engine.

The Japanese Sparrowhawks were flown from the Yokosuka Naval Base as well as from platforms built on gun turrets of warships.