Bristol Boxkite

https://en.wikipedia.org/wiki/Bristol_Boxkite

The Boxkite (officially the Bristol Biplane) was the first aircraft produced by
the British and Colonial Aeroplane Company (later known as the Bristol Aeroplane
Company). A pusher biplane based on the successful Farman III, it was one of the
first aircraft types to be built in quantity. As the type was used by Bristol
for instruction purposes at their flying schools at Larkhill and Brooklands many
early British aviators learned to fly in a Boxkite. Four were purchased in 1911
by the War Office and examples were sold to Russia and Australia. It continued
to be used for training purposes until after the outbreak of the First World
War.

The Boxkite was a two-bay biplane with an elevator carried on booms in front of
the wings and an empennage consisting of a pair of fixed horizontal stabilisers,
the upper bearing an elevator, and a pair of rudders carried on booms behind the
wing. There were no fixed vertical surfaces. Lateral control was effected by
ailerons on both upper and lower wings. These were single-acting, the control
cables arranged to pull them down only, relying on the airflow to return them to
the neutral position. The wings and fixed rear horizontal surfaces were covered
by a single layer of fabric: the other surfaces were covered on both sides.
Power was usually provided by a 50 hp (37 kW) Gnome rotary engine, although
other engines were also used. This was mounted on a pair of substantial wooden
beams mounted above the lower wing: these continued forward to carry the seats,
which were arranged in tandem, with the pilot sitting over the leading edge of
the wing. The undercarriage consisted of a pair of long skids, each bearing a
pair of wheels sprung by bungee cords, and a single sprung tailskid mounted
below the leading edge of the lower tailplane. The first two Boxkites, assigned
works numbers 7 and 8, differed in detail from the later production aircraft;
the front outrigger booms were braced by a pair of vertical struts and were
attached to the ends of the interplane struts. This arrangement was inherited
from the Zodiac, being necessary in that aircraft because the front spar of the
wing did not also form the leading edge. Additionally the rear elevator had a
straight trailing edge. No. 8 also had double-surfaced wings; the wings of No. 7
were single-surfaced with the ribs enclosed in pockets, like production
aircraft. No. 7 was initially fitted with a 50 hp (37 kW) Grégoire, but for its
first flight this was replaced by a Gnome, although the Grégoire was later
refitted for trial purposes: No. 8 had a 50 hp (37 kW) E.N.V.

Two modified Boxkites were produced for competition purposes. The first, No. 44,
was a single-seater built to compete in the 1911 Circuit of Europe air race and
had reduced wingspan and a nacelle for the pilot, similar to the Bristol Type T.
The second, No.69, was a redesign by Gabriel Voisin, who was employed as a
consultant by Bristol. This had no front elevator, monoplane tail with a single
rudder, and a reduced gap between the wings. It was tested at Larkhill in
February 1912, but was evidently unsuccessful since it was soon rebuilt as a
standard Boxkite and was to crash in November 1912.

Production continued until 1914 with a total of 78 being built, 60 of which were
the extended Military Version, one racer (No. 44) and the voisin variant (No.
69); all but the last six aircraft were built at Filton. The remaining six were
built at Brislington by the Tramway Company.


Role
Two-seat trainer

Manufacturer
British and Colonial Aeroplane Company

First flight
30 July 1910

Introduction
1910

Primary users
Bristol Aeroplane Company flying schools.
RFC
Imperial Russian Air Service
Australian Flying Corps

Produced
1910–14

Number built
78

Unit cost

£1,000 with engine


Developed from
Farman III, Zodiac Biplane

After the successful flight on Salisbury Plain No. 7 and a second aircraft, No.
8, were sent to Lanark to take part in the aviation meeting held there in
August. These aircraft were then assigned to the Bristol flight schools, No. 7
at Brooklands and No. 8 at Larkhill. In September a third aircraft was completed
and delivered to Larkhill, and both the Larkill machines participated in the
Army manoeuvres held on Salisbury Plain that month. No. 8 was flown by Bertram
Dickson, and was captured by Blue team cavalry when it landed in order to report
by telephone, and No. 9 by Robert Loraine. This aircraft was equipped with a
radio transmitter for trials and was the first aeroplane in the United Kingdom
to send a message by radio.

On 14 March 1911, the British War Office ordered four Boxkites for the planned
Air Battalion Royal Engineers, the first production contract for military
aircraft for Britain's armed forces. The first Boxkite, powered by a 50 hp Gnome
engine, was delivered to Larkhill on 18 May that year. An order for a further
four Boxkites was placed later that year, with the type mainly being used as a
trainer. They continued in use with the Air Battalion and Royal Flying Corps
(RFC) until December 1912. Four more Boxkites were purchased by the RFC from the
Bristol flying school at Brooklands following the outbreak of the First World
War, with the last of these four Boxkites written off in February 1915. The
Royal Naval Air Service (RNAS) also made use of the Boxkite as a trainer, being
used at its training schools at Eastbourne, Eastchurch and Hendon Aerodrome
until at least 1915.

The majority of the aircraft produced were employed at the Bristol flying
schools at Brooklands and Larkhill. These schools were responsible for training
nearly half the pilots who gained licences in Britain before the First World
War, and many distinguished pilots gained their licence in a Boxkite, including
Brigadier-General Henderson, the first commander of the Royal Flying Corps, who
gained his licence after less than a week of instruction.

Specifications (military version)

General characteristics
Crew: 2
Length: 38 ft 6 in (11.73 m)
Wingspan: 46 ft 6 in (14.17 m)
Height: 11 ft 0 in (3.61 m)
Wing area: 517.0 ft² (48.03 m²)
Empty weight: 900 lb (408 kg)
Max. takeoff weight: 1150 lb (522 kg)
Powerplant: 1 × Gnome Omega rotary piston engine, 50 hp (37 kW)

Performance
Maximum speed: 40 mph (64 km/h)
Wing loading: 2.22 lb/ft² (10.9 kg/m²)
Power/mass: 0.043 hp/lb (70.9 W/kg)




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