The Triplane was developed by the firm's experimental department as a private venture, the project was headed by the designer Herbert Smith.

Aside from its obvious difference in wing configuration, the aircraft shared many similarities with the company's successful biplane fighter, the Sopwith Pup.

Praise for the type extended to opposing pilots; Imperial Germany extensively studied the Triplane via captured examples and produced numerous tri-winged aircraft shortly thereafter.

Surviving Triplanes continued to serve as operational trainers and experimental aircraft until months following the end of the conflict.

[3] It was amid this conflict that one of its employees, Herbert Smith, designed the Sopwith Pup, a single-seat biplane fighter aircraft which was described by aviation author J.M.

[3] While it was a capable fighter that possessed impressive handling qualities for its era, from an aerodynamic perspective, the Pup was an entirely conventional design.

Certain figures, including those within Sopwith's experimental department, sought to develop a successor which would instead pioneer new concepts for such an aircraft; out of such ambitions would emerge the Triplane.

[3] The initial "prototype of what was to be referred to simply as the Triplane" first flew on 28 May 1916, with Sopwith test pilot Harry Hawker at the controls.

[7] While initially lacking any armament, N500 was subsequently furnished with a single Vickers machine gun, which was mounted centrally in front of the cockpit.

Being put into action within 15 minutes of its arrival to intercept enemy aircraft, N500 quickly proved to be highly successful.

[10] Seeking modern aircraft for the Royal Flying Corps (RFC), the War Office also issued a contract to Clayton & Shuttleworth for 106 Triplanes.

[11][14][15] While both Sopwith and Clayton & Shuttleworth successfully fulfilled their RNAS production orders,[10] Oakley, which had no prior experience building aircraft, delivered only three Triplanes before its contract was cancelled during October 1917.

[16][17] For unknown reasons, the RFC Triplane contract issued to Clayton & Shuttleworth was simply cancelled rather than being transferred to the RNAS.

[1][14] The Sopwith Triplane was a single seat fighter aircraft; it shared a considerable amount of its design features, such as its fuselage and empennage, with those of the earlier Pup.

One innovation that was present only on the Triplane was the use of single broad-chord interplane struts, which ran continuously between the lower and upper wings.

[18] The original tail assembly was identical to the Pup's, other than the inclusion of the variable incidence tailplane, which could be adjusted so that the aircraft could be flown hands-off.

At least one Triplane was tested with a 110 hp Le Rhône rotary engine, but this did not provide a significant improvement in performance, the only seeming benefit being a slight increase in its rate of climb.

[22] All but one British Triplane were dispatched to squadrons based in France; this sole aircraft was instead sent to the Aegean, although its service details and purpose there is largely unknown, only that its use was curtailed after a crash-landing in Salonika on 26 March 1917.

The new fighter's exceptional rate of climb and high service ceiling gave it a marked advantage over the Albatros D.III, though the Triplane was slower in a dive.

This defect was attributed to the use of light gauge bracing wires in the 46 aircraft built by subcontractor Clayton & Shuttleworth.

For a time, the type remained in use for experimental and training purposes; examples were recorded as performing flights as late as October 1918.

These were John Albert Page (7), Thomas Culling (6), Cyril Askew Eyre (6), F. H. Maynard (6), Gerald Ewart Nash (6) and Anthony Arnold (5).

73: The Sopwith Triplane[55]General characteristics Performance Armament Related development Aircraft of comparable role, configuration, and era