In April 1918, the sixth Snipe prototype was fitted with a 320 hp (239 kW) ABC Dragonfly I radial engine.[1] [2] To compensate for the greater weight of the Dragonfly, the fuselage was lengthened by 22 in (56 cm).[3]
The prototype suffered persistent ignition system defects, but performance was encouraging when the Dragonfly engine operated properly.[4] [5] In June 1918, the Royal Air Force issued a contract for 30 Dragonfly-engined Snipes, which were subsequently named Dragons.[6] [7] In late November 1918, the RAF cancelled a production order for 300 Snipes and reordered the aircraft as Dragons.[8]
A second prototype was equipped with the larger 360 hp (268 kW) ABC Dragonfly IA engine.[9] This aircraft did not begin official trials at Martlesham Heath until February 1919.[10] It attained a top speed of 150 mph (240 km/h) at sea level and achieved a service ceiling of 25,000 ft.[11]
Sopwith built approximately 200 Dragon airframes, which were placed in storage pending delivery of their engines.[12] Difficulties with the Dragonfly ultimately proved impossible to resolve. Only a few aircraft were completed with Dragonfly engines, and none were issued to squadrons.[13] The Dragon was finally declared obsolete in April 1923.[14]