Junkers Ju.52/3m. Part one

 

The Junkers Ju.52/2m was similar to the company's previous W.33, albeit larger. It was designed in 1930 by aeronautical engineer Ernst Zindel  and his team at Junkers factory in Dessau. According to some authors, it was drawn directly upon the Junkers J.I, world's first all-metal aeroplane.

The first prototype was flown on 13th October 1930, under the designation of Ju.52/ba. It was initially powered by a single Junkers-built liquid-cooled V-12 engine which could generate up to 800 hp of power. During the long prototype testing stage, it was re-engined with the BMW IV engine which delivered up to 755 hp of power. The second prototype, denominated Ju.52de, had an increased wingspan and, although it was powered by the BMW IV at first, soon it was replaced with the 750 hp Armstrong Siddeley Leopard which the company bought from British stocks. Consequently, the prototype was renamed as the Ju.52di. This machine was re-engined again with the 750 hp Junkers Jumo 204 and received the denomination of Ju.52do. The third prototype, designated as Ju.52ce, featured an strengthened structure, a modified leading edge and could be fitted with both wheeled and float undercarriages.

In May 1931, during one of test flights, Ju.52cai, one of the prototypes, crashed and was written off. While all those initial prototypes were powered by a single engine, Junkers decided to develop the Ju.52 into a trimotor, and so, the Ju.52/3m (drei motoren - three engines) started development process, being powered by an arrangement of three radial engines. By mid-1930s the Ju.52/3mce and Ju.52/3fe were the two primary production variants, both powered by the BMW 132 radial engine. 

In 1934 work commenced on a militarised model, named Ju.52/3mg3e on behalf of the, back then, secret Luftwaffe. This model could work as a medium bomber and be equipped with two defensive gun turrets if needed, with a crew of four. Between the years 1934 and 1935 a total of 450 Ju.52/3mg3e were delivered to the clandestine Luftwaffe.

In May 1932 Lufthansa, Germany's main airline, took delivery of its first Ju.52/3m. The type was heavily employed by Lufthansa, which covered both Berlin-Rome and Berlin-London routes with the Ju.52/3m as it could complete the first one in just 8 hours, quite a respectable time for the time. Lufthansa's Ju.52 fleet numbered 231 machines at its peak, before World War 2, as it was flown in various routes in Europe, Asia and South America.

Sources:

1. https://en.wikipedia.org/wiki/Junkers_Ju_52

2. Signal Squadron - Aircraft in Action 186 - Junkers Ju.52 in Action