The

Junkers Junkers Flugzeug- und Motorenwerke AG (JFM, earlier JCO or JKO in World War I, English: Junkers Aircraft and Motor Works) more commonly Junkers , was a major German aircraft and aircraft engine manufacturer. It was founded there in Dessau, Germ ...

Ju 252 was a German

cargo aircraft A cargo aircraft (also known as freight aircraft, freighter, airlifter or cargo jet) is a fixed-wing aircraft that is designed or converted for the carriage of air cargo, cargo rather than passenger aircraft, passengers. Such aircraft usually ...

that made its

first flight The maiden flight, also known as first flight, of an aircraft is the first occasion on which it leaves the ground under its own power. The same term is also used for the first launch of rockets. The maiden flight of a new aircraft type is alwa ...

in late October 1941. The aircraft was planned as a replacement for the

Junkers Ju 52/3m Junkers Flugzeug- und Motorenwerke AG (JFM, earlier JCO or JKO in World War I, English: Junkers Aircraft and Motor Works) more commonly Junkers , was a major German aircraft and aircraft engine manufacturer. It was founded there in Dessau, Germ ...

in commercial airline service, but only a small number were built as cargo aircraft for the

Luftwaffe The ''Luftwaffe'' () was the aerial-warfare branch of the German ''Wehrmacht'' before and during World War II. Germany's military air arms during World War I, the ''Luftstreitkräfte'' of the Imperial Army and the '' Marine-Fliegerabtei ...

Design and development

The original Ju 252 came about after talks between Junkers and

Deutsche Lufthansa Deutsche Lufthansa AG (), commonly shortened to Lufthansa, is the flag carrier of Germany. When combined with its subsidiaries, it is the second- largest airline in Europe in terms of passengers carried. Lufthansa is one of the five founding m ...

in December 1938. Lufthansa requested a new design that would replace the Ju 52, but offer much greater loads, seating, range and performance. Junkers responded with the EF.77 design with a pressurized fuselage with seating for up to 35, making it one of the larger airliners in the world at that time. It was powered by three

Junkers Jumo 211 The Jumo 211 was a German inverted V-12 aircraft engine, Junkers Motoren's primary aircraft engine of World War II. It was the direct competitor to the Daimler-Benz DB 601 and closely paralleled its development. While the Daimler-Benz engin ...

F engines, in nacelles almost identical in appearance, each complete with annular radiator and possibly as ''Kraftei'' unitized "

power-egg A power-egg is a complete "unitized" modular engine installation, consisting of engine and all ancillary equipment, which can be swapped between suitably designed equipment, with standardised quick-changing attachment points and connectors. In a ...

" modular engine installations, to those on Jumo 211-powered versions of the

Junkers Ju 88 The Junkers Ju 88 is a German World War II ''Luftwaffe'' twin-engined multirole combat aircraft. Junkers Aircraft and Motor Works (JFM) designed the plane in the mid-1930s as a so-called ''Schnellbomber'' ("fast bomber") that would be too fast ...

, replacing the

BMW 132 The BMW 132 was a nine-cylinder radial aircraft engine produced by BMW starting in 1933. Design and development BMW took over a license for manufacturing air-cooled radial engines from Pratt & Whitney on 3 January 1928. The nine-cylinder model ...

of the Ju 52, which dramatically improved performance. Compared to the Ju 52, the Ju 252 was twice as heavy (13,100 kg vs. 5,600), was over 100 km/h faster (440 km/h vs. 305), and had dramatically improved range (3980 km vs. 1300) when fully loaded. Design was headed by Konrad Eicholtz. By the time the prototype was ready to fly in October 1941, the war was already in progress and the Luftwaffe took over development. Like earlier tail-dragger designs, the Ju 252 would normally be difficult to load when parked, owing to the sloping floor. Junkers had already pioneered - with the earlier

Junkers Ju 90 The Junkers Ju 90 was a 40-seat, four-engine airliner developed for and used by Deutsche Luft Hansa shortly before World War II. It was based on the rejected Ju 89 bomber. During the war, the ''Luftwaffe'' impressed them as military transports ...

's fifth and sixth prototype airframes during 1939 - a unique solution to this problem, the ''Trapoklappe'', a hydraulically powered

ventral Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Th ...

rear loading ramp that possessed powerful enough operating mechanisms to lift the plane off its tailwheel, leveling the floor and allowing oversized cargo to be loaded directly forward into the fuselage. Even though all cargo aircraft since World War II have used

tricycle landing gear Tricycle gear is a type of aircraft undercarriage, or ''landing gear'', arranged in a tricycle fashion. The tricycle arrangement has a single nose wheel in the front, and two or more main wheels slightly aft of the center of gravity. Tricycle g ...

undercarriage designs, the ''Trapoklappe'' concept of a rear loading ramp that forms the opening rear ventral panel of the fuselage of a cargo aircraft, is a ubiquitous feature of most military airlift cargo aircraft to the present day. Although the Ju 252 was a vast improvement over the Junkers Ju 52/3m, the situation at that time did not permit any disruption of the existing production lines, and the

Reich Air Ministry The Ministry of Aviation (german: Reichsluftfahrtministerium, abbreviated RLM) was a government department during the period of Nazi Germany (1933–45). It is also the original name of the Detlev-Rohwedder-Haus building on the Wilhelmstrasse ...

(RLM) was of the opinion that any replacement for the Junkers Ju 52/3m must make minimum demands on supplies of

strategic material Strategic material is any sort of raw material that is important to an individual's or organization's strategic plan and supply chain management. Lack of supply of strategic materials may leave an organization or government vulnerable to disru ...

s and use power plants not required by combat aircraft. Junkers was then instructed to investigate the possibility of redesigning the Ju 252 in order that a considerable portion of wood could be included in its structure, simultaneously replacing the

F engine with the BMW

Bramo 323 The Bramo 323 ''Fafnir'' is a nine-cylinder radial aircraft engine of the World War II era. Based heavily on Siemens/Bramo's earlier experience producing the Bristol Jupiter under licence, the Bramo 323 saw limited use. Design and development ...

R engine of which surplus stocks existed. The result was the

Junkers Ju 352 The Junkers Ju 352 ''Herkules'' ("Hercules" in German) was a German World War II transport aircraft that was developed from the Junkers Ju 252. Design and development During the late spring of 1942, the Junkers-Dessau project office was instructe ...

. Production of the Ju 252 was restricted to already completed prototypes plus those for which major assemblies had already been semi-completed, thus only fifteen transports of this type were completed before production was switched to the Junkers Ju 352.

Variants

Ju 252, initial variant. 15 built. Ju 352, redesign of the Ju 252 constructed of non-strategic materials and powered by Bramo 323R radial engines. 50 built. Ju 452, derivative of the Ju 252 to be constructed from wood.

Specifications (Ju 252A)

References

External links

Luftwaffe Resource Center

Probert Encyclopedia
{{Authority control 1940s German military transport aircraft World War II transport aircraft of Germany Ju 252 Trimotors Low-wing aircraft Aircraft first flown in 1942

Design and development

Variants

Specifications (Ju 252A)

See also

References

External links