The Praga E-51 is a
Czechoslovakia
Czechoslovakia ( ; Czech language, Czech and , ''Česko-Slovensko'') was a landlocked country in Central Europe, created in 1918, when it declared its independence from Austria-Hungary. In 1938, after the Munich Agreement, the Sudetenland beca ...
n
reconnaissance aircraft
A reconnaissance aircraft (colloquially, a spy plane) is a military aircraft designed or adapted to perform aerial reconnaissance with roles including collection of imagery intelligence (including using Aerial photography, photography), signals ...
and light bomber built by
Praga
Praga is a district of Warsaw, Poland. It is on the east bank of the river Vistula. First mentioned in 1432, until 1791 it formed a separate town with its own city charter.
History
The historical Praga was a small settlement located at the e ...
in the 1930s.
Development was halted by the annexation of Czechoslovakia by
Germany
Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...
, after only one prototype had been built. The appearance of the construction is very reminiscent of the contemporary twin engined fighter, the
Fokker G.I from Holland.
Design and development
The unconventional
twin-boom
A twin-boom aircraft has two longitudinal auxiliary spars, or “auxiliary booms” , that may contain ancillary components such as fuel tanks and/or provide a supporting structure for other items. Typically, twin tailbooms support the tail ...
airplane project under
Jaroslav Šlechta began in 1936 as a response to a
Ministry of National Defence specification which called for the design and construction of a new reconnaissance aircraft to operate over combat zones. The short-range reconnaissance three-seater was to be capable of monitoring activity behind enemy lines; the requirement highlighted the importance of good view from the cockpit as well as of placement of the on-board cameras, which were to be able to collect as many shots as possible at as wide an angle as possible in one flyover.
The new aircraft was to replace the aging
Letov Š-328 and
Aero A.100. There were three entries to the tender: the
Letov Š-50, the ČKD-Praga E-51 and the
Aero A.304.
The E-51 was designed as a twin-boom twin-engine
mid-wing aircraft
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 conf ...
with a central
nacelle
A nacelle ( ) is a streamlined container for aircraft parts such as Aircraft engine, engines, fuel or equipment. When attached entirely outside the airframe, it is sometimes called a pod, in which case it is attached with a Hardpoint#Pylon, pylo ...
housing the cockpit and armament; the booms were elongations of the engine nacelles and each carried a
rudder
A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, airship, or other vehicle that moves through a fluid medium (usually air or water). On an airplane, the rudder is used primarily to counter adverse yaw ...
, with the
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 ...
placed between them. The E-51 was Šlechta's first design based on such a configuration. Because the reconnaissance airplane had to be able to escape enemy fighters, a high top speed was a number one priority, meaning a suitable engine had to be found. Šlechta considered three options: the inline
Praga FR with an output of 456 kW/355 hp, the inverted V-12
Walter Sagitta
The Walter Sagitta was a Czechoslovakian, air-cooled, inverted V-12 engine that first ran in 1937. This was one of several smaller, low-mass medium power pre-war V-12 engines produced. With a displacement of 18.4 liters (1,123 cubic inch, cu in) ...
with an output of 367-412 kW/500-600 hp, and the radial 9-cylinder
Avia Rk.17 at 261 kW/355 hp. As Praga's FR had not been finished yet and the Rk.17 was not powerful enough, Šlechta opted for the Sagitta. It was the first and only implementation of the Czechoslovak engine by
Walter Aircraft Engines
Walter Aircraft Engines is an aircraft engine manufacturer and former automotive manufacturer. Its notable products include the M601 turboprop. The company is based in Prague, Czech Republic. It has been a subsidiary of GE Aerospace since Jul ...
in a Czechoslovak airplane.
The aircraft was made using Czechoslovakia-supplied material and fitted with Czechoslovak (with a few exceptions) armaments. The simple wood and welded steel-tubes frame made both assembly and maintenance easy, and operation as well. The durability of the skin allowed for outdoor storage while on duty. The design is said to precede that of the
Fokker G.I, a more well-known example of the same design configuration, as the latter has, unlike the E-51, actually entered service.
The E-51 was the last design by Praga before World War II began.
Gallery
Specifications (E-51)
References
Further reading
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External links
Praga E-51na vhu.cz
na panzernet.net
Praga E-51: moderní československý průzkumníkna iDNES/blog
{{Praga aircraft
E-51
1930s Czechoslovak military reconnaissance aircraft