Breguet Bre.520 и Bre.521 Bizerte

В 1931 году фирма "Breguet" приобрела у "Short Brothers" лицензию на выпуск летающих лодок-бипланов Calcutta, а в 1932 году предложила морской авиации Франции, нуждавшейся в дальней летающей лодке разведывательного назначения, свой самолет Bre.520, разработанный на основе самолета Calcutta. Летающая лодка Breguet Bre.521 Bizerte сохранила компоновку предшественницы, но отличалась цельнометаллической конструкцией, стабилизирующими поплавками под нижним крылом, подкосным стабилизатором и силовой установкой из трех двигателей, смонтированных на подкосах между верхним и нижним крыльями. На выполнившем первый полет 11 сентября 1933 года прототипе Bre.521.01 стояло три незакапотированных мотора Gnome-Rhone 14Kdrs мощностью по 845 л. с. (630 кВт). Официальные испытания начались в январе 1934 года, к этому времени моторы закрыли капотами типа NACA. ВМС Франции заказали три предсерийных Bre.521 еще до завершения испытаний, первый из этих самолетов поднялся в воздух в 1935 году.
   В конструкцию второй предсерийной лодки внесли значительное количество изменений, ставших стандартными для всех последующих самолетов. Изменения коснулись исключения открытой стрелковой точки в носовой части корпуса, удлинения передней части фонаря кабины, а также оборудования новых закрытых блистерами стрелковых точек по бортам корпуса и одной - в хвостовой части.
   Поставки серийных лодок начались в 1935 году, а к 1940 году был собран 31 самолет, включая прототип. В октябре 1939 года летающие лодки данного типа состояли на вооружении пяти эскадрилий. В вооруженных силах правительства режима Виши самолеты состояли на вооружении двух эскадрилий, остальные расформировали в июне 1940 года; четыре самолета поступили на вооружение германских Люфтваффе.


Варианты

   Bre.522: один Bre.521, переоснащенный моторами Hispano-Suiza 14AA мощностью по 1 000 л. с. (746 кВт)
   Bre.530 Saigon: гражданский пассажирский вариант самолета Bizerte с тремя моторами Hispano-Suiza 12Ybr мощностью по 785 л. с. (488 кВт); пилот и второй пилот размещены под фонарем увеличенной высоты, а три салона предназначены для перевозки 11 пассажиров во втором классе, шести - в первом классе и трех - в классе "люкс". Построено всего два Bre.530, которые авиакомпания "Air France" использовала в начале 1935 года на линии Марсель - Аяччо (Корсика) - Тунис.


ТАКТИКО-ТЕХНИЧЕСКИЕ ХАРАКТЕРИСТИКИ

   Breguet Bre.521 Bizerte

   Тип: дальняя морская разведывательная летающая лодка с экипажем из восьми человек
   Силовая установка: три звездообразных мотора Gnome-Rhone 14Kirs или 14N-11 мощностью по 900 л. с. (671 кВт)
   Летные характеристики: максимальная скорость на высоте 1000 м - 245 км/ч; крейсерская скорость на оптимальной высоте 200 км/ч; время набора высоты 2000 м-8 мин 46 с; практический потолок 6000 м; дальность 3000 км
   Масса: пустого 9470 кг; максимальная взлетная 16600 кг
   Размеры: размах крыла 35,15 м; длина 20,50 м; высота 7,45 м; площадь крыльев 162,60 м2
   Вооружение: два 7,5-мм пулемета Darne на турелях по бортам фюзеляжа, один 7,5-мм пулемет Darne на хвостовой турели, а также до 300 кг бомб на внешней подвеске под нижним крылом.

Flight, October 1934

THE BREGUET "SAIGON
A Commercial Flying Boat Developed from the Short "Calcutta," three of which were bought by the Breguet Firm in 1930

   A NEW Breguet commercial flying boat, the "Saigon," which has been undergoing its trial tests at the San Raphael base, should be in operation on the Marseilles-Algiers line of Air France during this month.
   This machine has accommodation for nineteen passengers. It is equipped with three "Hispano-Suiza type Ybrs engines, rated at 835 h.p. each at sea level, and weight, loaded about 14 tons, being a counterpart of the military seaplane "Bizerte" recently put in service by the French Navy. While the hull is somewhat similar to that of the Short "Calcutta," the wing structure differs greatly, the Breguet machine being constructed as a sesquiplane.
   The "Saigon" has an upper wing span of 35.06 ms. (114 ft.) and a lower one of 18.89 ms. (61ft. 5in.). The wings are mounted at a. dihedral angle of 3 deg. with an incidence of 4 deg. They have an aspect ratio of 10.2 with a constant chord their entire span and terminate in rounded ends.

Wing Structure

   Three duralumin spars, one of which is mounted along the leading edge, the second along the trailing edge, and the main spar in the centre, are braced by a double system of interlaced duralumin ribs (in "X" form) joined by steel fittings, which assure a rigid construction to take the torsion loads. The wings are covered with fabric.
   The upper wings consist of two parts, a centre section and two outboard panels, while the lower wing is constructed in four parts. The two sections, inboard from the engine nacelles, are built into the fuselage, and have but two spars, the central spar installed in the two outboard panels being replaced by a rigid skin covering, forming a ''cat walk'' for access to the engines While in flight. The upper and lower wings are interconnected and braced by a system of slanting "Vee" streamlined struts, which also support the engine nacelles. The trailing edges of the wings are equipped with flaps of the special Breguet automatic trailing edge type. All the wing and strut fittings are made of stainless steel. The total wing area is 169.75 sq. ms. (1,827 sq.ft.).
   The hull, which is 20.3 metres (67ft.) in length, with a beam of 11ft., and with a total height of 8ft. Gin., is of rectangular form, with a concave "Vee" bottom constructed with two steps. Aft of the second step, the hull takes an oval shape and tapers down towards the stem. The upper portion and framework are constructed of duralumin, treated by the anodic oxidation process to resist corrosion, while the bottom is constructed of stainless steel up to slightly above the water line.
   The hull structure consists of transverse frames reinforced by closely spaced longitudinal stiffeners and covered by a duralumin plating, which also serves as a stress-carrying member. This framework is further reinforced by three heavy transverse frames, two of which are in line with the spars of the centre section of the lower wing and into which these spars are built.
   A hold for baggage and equipment is installed in the bow of the hull, aft of which is located the radio room. The seats of the pilot and his assistant are side-by-side in an enclosed compartment, adjoining that of the radio operator, the roof of which is raised and transparent. A cabin with accommodation for eleven second class passengers is located aft of the pilot's compartment, adjoining which is another cabin fitted to receive six first class passengers, while, still further aft, is a stateroom for two people. There is room, therefore, for nineteen passengers. All these cabins are well lighted.
   A lavatory, a kitchen and a pantry are installed in the after part of the hull, while a large luggage hold is located in the extreme stern.
   The wing tip floats are mounted nearly 20ft. from the centre of the hull. Their upper portions are constructed of duralumin, while stainless steel has been used for their bottoms, which have a "Vee. " shaped concave form with a single step.
   The fixed tail plane is constructed with two spars, the front of which forms the leading edge. The spars, together with the frame work, are of duralumin and covered with fabric.
   The fin has a square form with a rounded upper corner and is secured directly to the hull. It has a surface area of 64 sq. ft. (5-95 sq. ms.) and is braced by wire cables to the fixed horizontal tail plane, which is in turn fastened to the hull by a bracing of three "Vee " struts on each side. The rudder is also square in form and has a surface area of 48 sq. ft. (4.45 sq. ms.), while the trailing edges of the elevators and rudder are equipped with compensating flaps adjustable in flight.

The Power Plant

   Three Hispano-Suiza 12-cylinder engines are used, these being water-cooled, geared (2:3), type 12 Ybrs. They are rated at 835 h.p. each, at ground level. These engines are lightly supercharged and produce 887 h.p. at 7,500 ft., and have a total capacity of 36 litres. They are fitted with three-bladed Gnome and Rhone steel propellers, with pitch adjustable at ground level.
   The engine nacelles are located in the "Vee" strut interbracing between the wings. They consist of three sections. The engine mountings, constructed of duralumin tubes, occupy the forward part; the fuel tanks, separated by a fire wall and supported by a heavy circular duralumin frame, are located behind the engines; while the oil tanks are in the extreme rear of the nacelles. The total capacity of the fuel tanks is some 1,000 British gallons, giving a flight radius of 1,250 miles. For the Marseilles-Algiers trip only 540 gallons will be carried, giving a cruising radius of 700 miles. Equipped for this trip the "Saigon" will weigh 13,800 kgs. (approx. 14 tons), and will carry a pay load of 2,000 kgs. (4,409 lb.).
   The estimated performances are as follow: - Maximum speed 230 km/hr (143 m.p.h.), cruising speed 190 km/hr (118 m.p.h.), ceiling 5,000 ms. (16,000 ft.), flight radius 1,100 kms. (700 miles).