[1][2] The prototype, powered by a 90 hp (67 kW) Cirrus Minor engine, and registration G-AEMA was first flown in May 1937 at London Air Park, Hanworth.

[1][2] It had a fixed tailwheel undercarriage and low cantilever wing with rounded wingtips and a split trailing edge flap that ran under the fuselage.

[1][8] In November 1938, GAL modified the prototype Cygnet with a new tail assembly, with twin fins and rudders, to improve the efficiency of the aircraft's elevators.

[8][9] GAL further modified the prototype early in 1939 with a nosewheel undercarriage, which had already been tested on a Monospar ST-25, with the intention of making the aircraft as safe and easy to fly as possible.

[12] While production of a large batch of aircraft was planned, only 10 are reported to have been built due to the start of the Second World War,[9] although no records are available for two of them, and it is possible that they may not have been completed.

The last flying survivor, company number 111 and registered as G-AGBN (ES915), was retired in 1988 and is now on display at the National Museum of Flight at East Fortune, Scotland.

[15][failed verification] A civilian version was operated in south Argentina, in Tierra del Fuego province where it was damaged in a landing incident.