[2] On the power of its 110 hp (82 kW) Le Rhone rotary engine it was not outstandingly fast but it was very manoeuvrable and proved popular with pilots as a safe and pleasant aircraft to fly.

[1] At least one of his machines was experimentally fitted with an 0.43 in (11 mm) Vickers machine-gun for use in balloon busting, something at which Coppens excelled.

The type was also supplied in small numbers to the Italians, who manufactured it in quantity and used it to replace Nieuports and SPADs.

These were mainly used as trainers, although they were also involved in experiments with take-off platforms on warships – they could be fitted with twin guns and at least one machine had a hydrovane and flotation bags of the type developed for the Royal Navy.

Five examples of the HD.1 are preserved in museums in Europe and the US: Data from Jane's Vintage Aircraft Recognition Guide [1]General characteristics Performance Armament