Template:Infobox Aircraft The Sopwith Triplane was a single seat fighter aircraft used by the Royal Naval Air Service during the First World War. It was designed by the Sopwith Aviation Company and nicknamed the Tripe or the Tripehound.

Design and development

The Triplane began as a private venture by the Sopwith Aviation Company. Chief engineer Herbert Smith gave the aircraft three narrow-chord wings to provide the pilot with the optimum field of view. Otherwise, the Triplane possessed a fuselage and empennage similar to that of the preceding Pup. Later triplanes had a smaller tailplane than the original "Pup" style one. The aircraft was initially powered by a 110 hp Clerget 9Z nine-cylinder rotary engine, but most production examples were fitted with a 130 hp Clerget 9B rotary. At least one Triplane was tested with a 110 hp Le Rhône rotary engine.

In July 1916, the prototype Triplane, serial N500, was sent to Dunkirk for evaluation with "A" Naval Squadron, 1 Naval Wing. It proved highly successful. A second prototype fitted with a 130 hp Clerget 9B, serial N504, was also sent to France for evaluation.

Operational history

Production commenced in late 1916. Apart from a few examples supplied to Great Britain's allies, the Triplane was flown exclusively by the Royal Naval Air Service. Originally a batch of aircraft were also destined for the Royal Flying Corps (RFC) ^[1], but in February 1917, the RFC orders were exchanged for the SPAD VIIs on order for the RNAS. For unknown reasons, most of the Triplanes ordered for the RFC were simply cancelled, rather than being transferred to the RNAS.

No. 1 Naval Squadron became operational with the Triplane by December 1916. Nos. 8, 9 and 10 Naval Squadrons equipped with the type in the spring of 1917. The only other major operator of the Triplane was a French Aviation Maritime squadron based at Dunkirk, which received 17 aircraft.

The Triplane's combat debut was highly successful. The exceptional rate of climb and high service ceiling of the Triplane gave it a marked advantage over the Albatros D.III - the only British type to have this edge during the period of German air superiority known as "Bloody April" 1917.

By almost all accounts, the Triplane was a pleasant and easy aircraft to fly, with effective, well-harmonised controls. By using the variable incidence tailplane, the fighter could be trimmed to fly hands-off. The introduction of the new eight-foot span tailplane in February 1917 improved elevator response. While the Triplane climbed faster and was more agile than most contemporary scouts, it was slower in a dive than German aircraft of the time.

Moreover, the Triplane earned a reputation for structural weakness. The wings sometimes collapsed under the strain of steep dives. This defect has been attributed to the use of light gauge bracing wires in the 47 aircraft built by subcontractor Clayton & Shuttleworth, although it may also have been a fault with the basic design, which used very few bracing wires. In any case, surviving aircraft that were used as advanced trainers were fitted with additional bracing to the upper centre section.

Another fault of the Triplane was its armament. Most Triplanes were armed with only one fixed synchronized Vickers machine gun. Six aircraft were fitted with twin Vickers guns, but performance was reduced, and the single gun remained standard.

The Triplane was famously flown by the "Black Flight" (of No. 10 Naval Squadron) which was commanded by the Canadian ace Raymond Collishaw. The unit claimed 87 German aircraft in three months while equipped with the Triplane. Collishaw himself scored 33 victories in the aircraft, making him the top scorer with the type.

Approximately 150 Triplanes were built. By the autumn of 1917, the Triplane's heyday had passed. Nos. 8, 9 and 10 Naval Squadrons converted to the Sopwith Camel between July and September, 1917. The last unit to operate the Triplane, No. 1 Naval Squadron, converted to Camels in December 1917. Nonetheless, the Germans were so impressed by the performance of the Triplane that it spawned a brief triplane craze among German aircraft manufacturers - although of all the German triplane designs only the Fokker Dr.I saw frontline service.

Operators

•  United Kingdom: Royal Naval Air Service
•  France (17 aircraft)
•  Russia (1 aircraft)
•  United States (1 aircraft)

Specifications (Clerget 9B-engined variant)

General characteristics

• Crew: 1

Performance