The Bristol B.R.7 was a Romanian-designed single-engine two-seat
biplane
A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While ...
built by Bristol to a Spanish government order in 1913. It failed to meet its specifications and the order was cancelled.
Development
The Romanian aircraft designer
Henri Coandă
Henri Marie Coandă (; 7 June 1886 – 25 November 1972)''Flight'' 1973 was a Romanian inventor, aerodynamics pioneer, and builder of an experimental aircraft, the Coandă-1910 described by Coandă in the mid-1950s as the world's first jet, a co ...
was appointed head designer at the Bristol Aeroplane Company in January 1912. He began by building the series of
Bristol-Coanda Monoplanes
The Bristol Coanda Monoplanes were a series of monoplane trainers designed by the Romanian designer Henri Coandă for the British company British and Colonial Aeroplane Company.
Several versions of the plane were built from 1912 onwards with ...
, but when the structural failure of one of these led to a
War Office
The War Office was a department of the British Government responsible for the administration of the British Army between 1857 and 1964, when its functions were transferred to the new Ministry of Defence (MoD). This article contains text from ...
ban on the use of
monoplane
A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes.
A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...
s by the
RFC
RFC may refer to:
Computing
* Request for Comments, a memorandum on Internet standards
* Request for change, change management
* Remote Function Call, in SAP computer systems
* Rhye's and Fall of Civilization, a modification for Sid Meier's Civ ...
, Coandă turned to biplane designs. His first such effort, a two-seat single-engine machine, attracted the interest of both the Spanish and German governments.
The Spanish requested the use of the 70 hp (50 kW)
Renault
Groupe Renault ( , , , also known as the Renault Group in English; legally Renault S.A.) is a French multinational automobile manufacturer established in 1899. The company produces a range of cars and vans, and in the past has manufactured ...
engine which they already used in their
Maurice Farman
Maurice Alain Farman (21 March 1877 – 25 February 1964) was a British-French Grand Prix motor racing champion, an aviator, and an aircraft manufacturer and designer.
Biography
Born in Paris to English parents, he and his brothers Richard and ...
s. The German version was to be built by
Deutsche Bristol-Werke using a 90 hp (70 kW)
Daimler
Daimler is a German surname. It may refer to:
People
* Gottlieb Daimler (1834–1900), German inventor, industrialist and namesake of a series of automobile companies
* Adolf Daimler (1871–1913), engineer and son of Gottlieb Daimler
* Paul Da ...
engine, so Coandă had to prepare a design suitable for both powerplants. The Renault-engined version become known as the B.R.7; the German design seems not to have had a distinct label. The first of five B.R.7s ordered for Spain appeared at the
Olympia Aero Show in February 1913, flying for the first time in March at
Larkhill
Larkhill is a garrison town in the civil parish of Durrington, Wiltshire, England. It lies about west of the centre of Durrington village and north of the prehistoric monument of Stonehenge. It is about north of Salisbury.
The settlement ...
. Its wings were of two-bay form with no
stagger. There were two tandem cockpits, one under the wing and the other, for the pilot behind the trailing edge. Behind the cockpits, the
fuselage
The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...
was quite slender, carrying a nearly semi-circular
tailplane
A tailplane, also known as a horizontal stabiliser, is a small lifting surface located on the tail (empennage) behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed-wing aircraft such as helicopters and gyroplane ...
with a one-piece
elevator
An elevator or lift is a wire rope, cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or deck (building), decks of a building, watercraft, ...
and a finless balanced
rudder
A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally aircraft, air or watercraft, water). On an aircraft the rudder is used primarily to ...
. The
undercarriage
Undercarriage is the part of a moving vehicle that is underneath the main body of the vehicle. The term originally applied to this part of a horse-drawn carriage, and usage has since broadened to include:
*The landing gear of an aircraft.
*The ch ...
had the unusual four-wheel form used by the monoplane, with a pair of large wheels mounted below the wing trailing edge and aft of the centre of gravity, together with a slightly smaller pair forward of the engine; the B.R.7 sat on the ground like a
tricycle undercarriage
Tricycle gear is a type of aircraft undercarriage, or ''landing gear'', arranged in a tricycle fashion. The tricycle arrangement has a single nose wheel in the front, and two or more main wheels slightly aft of the center of gravity. Tricycle ge ...
aircraft.
![Aviation in Britain Before the First World War RAE-O580](https://upload.wikimedia.org/wikipedia/commons/b/b2/Aviation_in_Britain_Before_the_First_World_War_RAE-O580.jpg)
Early tests showed the wings of the B.R.7 produced too little lift because they used the lower
camber
Camber may refer to a variety of curvatures and angles:
* Camber angle, the angle made by the wheels of a vehicle
* Camber beam, an upward curvature of a joist to compensate for load deflection due in buildings
* Camber thrust in bike technology
* ...
associated with monoplanes. The wings were replaced with a set with greater camber, which improved performance but not by enough to meet the specification. Experiments with a four-bladed propeller also failed to produce sufficient improvement and the Spanish contract was cancelled. The second machine was lost to fire and the remaining four of the Spanish order flew rarely. A final, seventh B.R.7 was fitted with larger-span wings, but the only example to do much flying was the first prototype, which remained in service at Larkhill as an advanced
trainer.
The German-built Daimler-engined machine had wings of much-increased span (from 38 ft/11.58 m to 57 ft/17.37 m) on the upper plane and a consequent increase in wing area of 30%.
It also had a larger rudder and
aileron
An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around ...
s. It flew in July 1913.
Specifications
References
Notes
Bibliography
*
{{Bristol aircraft
1910s British military aircraft
B.R.7
Aircraft first flown in 1913