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 p ...

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 planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

monoplane powered by a 52 kW (70 hp)

Gnome Gamma The Gnome 7 Gamma was a French designed, seven-cylinder, air-cooled rotary aero engine. Powering several pre-World War I era aircraft types it produced 70 horsepower (52 kW) from its capacity of 12 litres (680 cubic inches ...

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 i ...

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 a team of machines, animals or people are lined up one behind another, all facing in the same direction. The original use of the term in English was in ''tandem harness'', which is used for two ...

: 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 ''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 ...

tapered to a horizontal knife-edge at the tail, with the elongated triangular

horizontal stabiliser 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 gyroplan ...

mounted in the middle, its covering blending into that of the upper and lower fuselage surface. A semi-elliptical

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, ...

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. 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 opposite direc ...

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

Petrol Gasoline (; ) or petrol (; ) (see ) is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines (also known as petrol engines). It consists mostly of organic co ...

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 of the 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. This is one of the most fam ...

, with the wheels mounted on a trailing arm free to slide up and down and sprung by

bungee cords file:Bungee Cord PICT6882a.jpg, Bungee cords equipped with metal hooks A bungee cord (sometimes spelled bungle; also known as a shock cord) is an elastomer, elastic cord composed of one or more elastic strands forming a core, usually covered in a w ...

. 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 and stringer is the 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 ...

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 and stringer is the 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 ...

and forming the front of the raked engine cowling. The tailskid was made of two U-shaped pieces of

rattan cane Rattan, also spelled ratan, is the name for roughly 600 species of Old World climbing palms belonging to subfamily Calamoideae. The greatest diversity of rattan palm species and genera are in the closed-canopy old-growth tropical forests of ...

. 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