https://en.wikipedia.org/wiki/Sopwith_Triplane
The Sopwith Triplane was a British single seat fighter aircraft designed and
manufactured by the Sopwith Aviation Company during the First World War. It was
the first military triplane to see operational service. The Triplane joined
Royal Naval Air Service squadrons in early 1917 and was immediately successful.
It was nevertheless built in comparatively small numbers and was withdrawn from
active service as Sopwith Camels arrived in the latter half of 1917. Surviving
Triplanes continued to serve as operational trainers until the end of the war.
The Triplane began as a private venture by the Sopwith Aviation Company. The
fuselage and empennage closely mirrored those of the earlier Pup, but chief
engineer Herbert Smith gave the new aircraft three narrow-chord wings to provide
the pilot with an improved field of view. Ailerons were fitted to all three
wings. By using the variable incidence tailplane, the aircraft could be trimmed
to fly hands-off. The introduction of a smaller 8 ft span tailplane in February
1917 improved elevator response.
The Triplane was initially powered by the 110 hp Clerget 9Z nine-cylinder rotary
engine, but most production examples were fitted with the 130 hp Clerget 9B
but this did not provide a significant improvement in performance.
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.
Within three minutes of takeoff, Hawker startled onlookers by looping the
aircraft, serial N500, three times in succession. The Triplane was very agile,
with effective, well-harmonised controls. When maneuvering, however, the
Triplane presented an unusual appearance. One observer noted that the aircraft
looked like "a drunken flight of steps" when rolling.
Role
Fighter
National origin
United Kingdom
Manufacturer
Sopwith Aviation Company
Designer
Herbert Smith
First flight
28 May 1916
Introduction
December 1916
Primary user
Royal Naval Air Service
Number built
147
No. 1 Naval Squadron became fully operational with the Triplane by December
1916, but the squadron did not see any significant action until February 1917,
when it relocated from Furnes to Chipilly. No. 8 Naval Squadron received its
Triplanes in February 1917. Nos. 9 and 10 Naval Squadrons equipped with the type
between April and May 1917. The only other major operator of the Triplane was a
French naval squadron based at Dunkirk, which received 17 aircraft.
The Triplane's combat debut was highly successful. 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. The Germans were so
impressed by the performance of the Triplane that it spawned a brief triplane
craze among German aircraft manufacturers. Their efforts resulted in no fewer
than 34 different prototypes, including the Fokker V.4, prototype of the
successful Fokker Dr.I.
For a variety of reasons, the Triplane's combat career was comparatively brief.
In service, the Triplane proved difficult to repair. The fuel and oil tanks were
inaccessible without substantial disassembly of the wings and fuselage. Even
relatively minor repairs had to be made at rear echelon repair depots. Moreover,
spare parts became difficult to obtain during the summer of 1917, and No. 1
Naval Squadron's complement was reduced from 18 to 15 aircraft.
The Triplane also gained a reputation for structural weakness because the wings
sometimes collapsed in steep dives. This defect was attributed to the use of
light gauge bracing wires in the 46 aircraft built by subcontractor Clayton &
Shuttleworth. Several pilots of No. 10 Naval Squadron used cables or additional
wires to strengthen their Triplanes. In 1918, the RAF issued a technical order
for the installation of a spanwise compression strut between the inboard cabane
struts of surviving Triplanes. One aircraft, serial N5912, was fitted with
additional mid-bay flying wires on the upper wing while used as a trainer.
Another drawback of the Triplane was its light armament. While contemporary
Albatros fighters were armed with two guns, most Triplanes were armed with a
single synchronised Vickers machine gun. Efforts to fit twin guns to the
Triplane met with mixed results. Clayton & Shuttleworth built six experimental
Triplanes with twin guns.
Specifications (Clerget 9B-engined variant)
General characteristics
Crew: 1
Length: 18 ft 10 in (5.73 m)
Wingspan: 26 ft 6 in (8 m)
Height: 10 ft 6 in (3.2 m)
Empty weight: 1,101 lb (500 kg)
Loaded weight: 1,541 lb (700 kg)
Performance
Maximum speed: 117 mph (187 km/h) at 5,000 ft (1,830 m)
Endurance: 2 hrs 45 min
Service ceiling: 20,500 ft (6,250 m)
Time to 6,000 ft (1,830 m): 5 min 50 s
Time to 16,400 ft (5,000 m): 26 min 30 s
Armament
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