Bleriot-SPAD S.81

Предшественником S.51 и S.61 был Bleriot-SPAD S.81.01, прототип которого поднялся в воздух 13 марта 1923 года. Он был одним из многих истребителей, спроектированных согласно техническому заданию ВВС Франции от 1922 года. Военные проявили интерес к истребителю с крылом типа парасоль Dewoitine D.1 и самолету S.81, ни один из других проектов не дошел до стадии постройки прототипов. Хотя D.1 имел более высокие характеристики, предпочтение было отдано S.81, конструкцию которого (фюзеляж - деревянный монокок, крыло металлическое, с полотняной обшивкой) сочли более прочной и надежной.
   Построили два прототипа S.81, второй использовался для статических испытаний. Затем последовал заказ на 80 серийных истребителей S.81/1C.1.

   По результатам испытаний конструкцию доработали - удлинили фюзеляж и увеличили площадь вертикального оперения. Первый серийный S.81/1 взлетел в сентябре 1924 года, а в декабре самолеты стали поступать на вооружение 2-го полка французских ВВС.
   S.81 имел опытные модификации, S.81/2 и S.81/3, взлетевшие 20 мая и 18 августа 1924 года и отличавшиеся в основном типом используемых радиаторов. Вариант 5.81/4 имел крыло деревянной конструкции. S.81 bis, взлетевший летом 1923 года, имел такой же двигатель, как истребитель, но отличался крылом уменьшенного размаха. Он предназначался для участия в гонках на Кубок Мишлен. Летные характеристики машины оказались невысоки, и позднее ее переделали в гоночный самолет S.81/6.

ТАКТИКО-ТЕХНИЧЕСКИЕ ХАРАКТЕРИСТИКИ

   Bleriot-SPAD S.81/1C.1

   Тип: одноместный истребитель
   Силовая установка: один двигатель жидкостного охлаждения Hispano-Suiza 8Fb мощностью 300 л. с. (224 кВт)
   Летные характеристики: максимальная скорость на высоте 500 м - 240 км/ч; время набора высоты 5000 м -14 мин; дальность полета 500 км
   Масса: пустого 846 кг; максимальная взлетная 1266 кг
   Размеры: размах крыла 9,61 м; длина 6,40 м; высота 2,90 м; площадь крыльев 30,00 мг
   Вооружение: два 7,7-мм пулемета Vickers в носовой части фюзеляжа

Flight, June 1924

THE THIRD INTERNATIONAL AERO SHOW AT PRAGUE
THE FRENCH EXHIBITS

BLERIOT-SPAD.

   THE Bleriot-Spad exhibit at Prague is one of the type 81 C.1 Scouts. This is a single-seater biplane fitted with a 300 h.p. Hispano-Suiza engine. The fuselage is well-streamlined, of elliptical cross-section, and is built up of layers of three-ply tulip wood, rolled and crossed over one another and covered with fabric. The engine section consists of two ply-wood spars supported by an arrangement of tubular steel and duralumin. In the lower part of the fuselage are two duralumin struts, to which are attached the bottom planes and the landing chassis. The top plane is in two sections, and is attached to a vertical panel, consisting of four steel tubes enclosed in an aluminium fairing, extending upwards from the fuselage. The lower plane, also in two parts, is attached to small wing-roots formed integral with the fuselage by the struts previously referred to.
   Upper and lower planes are built up on two rectangular duralumin spars, braced by duralumin tubes and steel wire, while the ribs are of pressed duralumin. The top plane is staggered forward 35 cm. (17 1/2 ins.). Upper and lower planes are separated by a single I-strut on each side of the fuselage. This strut is built up of duralumin, reinforced at the ends and attached to the wing spars by articulated joints. External bracing is of the usual lift and landing wires.
   The tail surfaces are of spruce, covered with ply-wood, the horizontal stabilising surface being in one piece, passing right through the fuselage, to which it is attached by riveted angle-pieces.
   The landing chassis consists of two pressed duralumin bearers or struts, in the lower ends of which are formed rectangular channels receiving the axle guides. The main petrol tank is located between the engine and the pilot's cockpit, and is detachable during flight. An auxiliary tank is mounted in the upper plane. Cooling is by two Lamblin radiators mounted on the fuselage below the engine. The principal characteristics of the Spad 81 C.1 are: Span (top), 8-804 m. (29 ft.); span (lower), 6-400 m. (21 ft.); wing area, 30 sq. m. (322-8 sq. ft.); weight, empty, 800 kgs. (1,760 lbs.); useful load, 450kgs. (990lbs.); wing loading, 41-600 kgs./sq. m. (8-5 lbs./sq. ft.); power loading, 4-160 kgs. h.p. (9 lbs./h.p.); speed. 250 km. per hour (155 m.p.h.); ceiling (full load), 8,000 m. (26,400 ft.).

Flight, December 1924

The Paris Aero Show 1924

BLERIOT AERONAUTIQUE

IT is to be feared that many visitors to the Grand Palais may have missed the Bleriot exhibits altogether, as the stand alloted to the famous French constructor is tucked away under one of the galleries. Of the exact cause for this we have no knowledge, but a rumour is current to the effect that M. Bleriot had at first decided not to exhibit, and that when, at the last minute, so to speak, he altered this decision all the main stands had been taken and he had to be satisfied with the present position, which is certainly not at all in keeping with the importance of one of France's oldest constructors and one of the pioneers of aviation.
Three machines are exhibited on the Bleriot stand, all of which are of typical Spad-Herbemont design, with monocoque fuselages and single-bay, I-strut wing bracing. The Spad 81 is similar to the machine exhibited at Prague last summer, when it was fully described and illustrated in FLIGHT. This machine, a single-seater fighter, is fitted as standard with 300 h.p. Hispano-Suiza engine, and has a speed at ground level of 250 km./h. (156 m.p.h.), while at 7,000 m. (23,000 ft.) the speed is 205-7 km./h. (128 1/2 m.p.h.). The machine is fitted with two Vickers or Darne machine-guns, and their supply of 800 rounds.
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