The Blériot XXI was an early French aircraft built by

Blériot Aéronautique Blériot Aéronautique was a French aircraft manufacturer founded by Louis Blériot. It also made a few motorcycles between 1921 and 1922 and cyclecars during the 1920s. Background Louis Blériot was an engineer who had developed the first practi ...

Design

The aircraft was a

shoulder-wing 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 wings. A monoplane has inherently the highest efficiency and lowest drag of any wing config ...

monoplane powered by a 52 kW (70 hp) Gnome Gamma 7-cylinder

rotary engine The rotary engine is an early type of internal combustion engine, usually designed with an odd number of cylinders per row in a radial configuration. The engine's crankshaft remained stationary in operation, while the entire crankcase and its ...

driving a two-bladed propeller. The pilot and passenger were seated in

side-by-side configuration Tandem, or in tandem, is an arrangement in which two or more animals, machines, or people are lined up one behind another, all facing in the same direction. ''Tandem'' can also be used more generally to refer to any group of persons or objects w ...

: the control column was centrally mounted and there were two sets of rudder pedals, so that it could be flown from either seat. The shallow section rectangular

fuselage The fuselage (; from the French language, French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds Aircrew, crew, passengers, or cargo. In single-engine aircraft, it will usually contain an Aircraft engine, engine as wel ...

tapered to a horizontal knife-edge at the tail, with the elongated triangular horizontal stabiliser mounted in the middle, its covering blending into that of the upper and lower fuselage surface. A semi-elliptical

elevator An elevator (American English) or lift (Commonwealth English) is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive traction cables and counterweight systems suc ...

was mounted on the trailing edge, and a triangular balanced rudder was mounted above the rear fuselage. Lateral control was effected by

wing-warping Wing warping was an early system for lateral (roll) control of a fixed-wing aircraft or kite. The technique, used and patented by the Wright brothers, consisted of a system of pulleys and cables to twist the trailing edges of the wings in opposit ...

, the wires leading to a single inverted V-strut cabane above the fuselage and a similar V strut beneath.

Petrol Gasoline (North American English) or petrol ( Commonwealth English) is a petrochemical product characterized as a transparent, yellowish, and flammable liquid normally used as a fuel for spark-ignited internal combustion engines. When formul ...

was stored in three tanks: a pair of gravity tanks were located under the top decking in front of the cockpit, pressure-fed from a larger tank under the seats. The undercarriage was a variant of the well-proved pattern used on the

Blériot XI The Blériot XI is a French aircraft from the Aviation in the pioneer era, pioneer era of aviation. The first example was used by Louis Blériot to make the first flight across the English Channel in a heavier-than-air aircraft, on 25 July 1909. ...

, with the wheels mounted on a trailing arm free to slide up and down and sprung by bungee cords. Unlike that of the Blériot XI, the main vertical members terminated in a crossbar below the fuselage rather than one attached to the upper

longeron In engineering, a longeron or stringer is a load-bearing component of a framework. The term is commonly used in connection with aircraft fuselages and automobile chassis. Longerons are used in conjunction with stringers to form structural fram ...

s, and it was also braced by a pair of diagonal struts either side, the front pair leading to the front of the upper

longerons In engineering, a longeron or stringer is a load-bearing component of a framework. The term is commonly used in connection with aircraft fuselages and automobile chassis. Longerons are used in conjunction with stringers to form structural frame ...

and forming the front of the raked engine cowling. The tailskid was made of two U-shaped pieces of rattan cane. A Type XXI was one of the two Blériot designs entered for the

1912 British Military Aeroplane Competition In 1911 the British War Office announced their first Military Aeroplane Competition for aircraft to meet the requirements of the Air Battalion Royal Engineers. The formal requirements were published in December 1911. By the time the trials were he ...

Specifications

References

{{DEFAULTSORT:Bleriot 21 1900s French experimental aircraft 21 Single-engined tractor aircraft Shoulder-wing aircraft Aircraft first flown in 1911