German Wings Resurgent
Aviation development in post First World War Germany had suffered under the restrictions placed upon the country as part of the armistice agreements. By the late 1920s and early 1930s, Germany moved in violation of the restrictions and began rebuilding both its industrial base and military.
In 1933, after several years in Sweden, Carl Bucker returned to his native Germany and set up an aircraft company under his own name in Berlin; accompanying Bucker to Germany was the young Swedish aircraft designer, Anders J. Andersson. The Bu-131 Jungmann would be the new company’s first design.
The Bu-131 had a surprisingly short development period of less than six months from design to maiden flight in April of 1934; more surprising is that it was an immediate success almost from the time of its first flight. The company was soon overwhelmed by orders for the aircraft to equip flying schools across Germany and Bucker needed to move to a larger factory.
The World Takes Notice
By 1935, the Bu-131 was a fixture at air clubs across Germany and had been selected as the primary basic trainer for the German air force, the Luftwaffe, which had been established in 1933. This was, however, only the beginning for the nimble and pilot friendly trainer.
The Bucker Jungmann attracted international interest very early in its life; this interest came not only in the form of export orders but also in requests to produce the aircraft under license in other nations. The aircraft was a clear commercial success in the years running up to the Second World War.
The first country to produce the aircraft under license was Switzerland with other production lines in Czechoslovakia, Japan and Spain established subsequently.
The Jungmann enjoyed particular success in central European countries. Hungary had around 120 while Bulgaria and Romania had fleets of 15 and 40 respectively. By far the largest customer of the aircraft was Yugoslavia who took delivery of around 400 units.
The aircraft secured sales of around 25 units between Brasil, Chile and Uruguay during a demonstration tour in 1938. South African private orders totaled 16 while smaller numbers of the aircraft found their way to civil operators within Europe.
A total of around 1400 were built for the Japanese navy and army between the assembly lines of the Kokusai and Kyushu companies.
Naturally, the outbreak of hostilities in 1939 saw production of the aircraft significantly increased and Axis aligned nations furnished with several more examples of the trainer.
At the outbreak of the war, Bucker themselves were known to have produced over 1000 examples of the Bu-131. While exact numbers do not exist, overall German wartime production of the aircraft is generally thought to be between 3000 and 4000 units.
In the prewar period, Czechoslovak production of the Bu-131 was undertaken by the Tatra company and was stopped after only a few aircraft were completed and a decision was made to discontinue license production of the aircraft in Czechoslovakia.
The German occupation of Czechoslovakia brought production of the Bu-131 back to that country, this time production would be done through the Prague based Aero company and would amount to many more units to meet Luftwaffe demands.
Persistent Production
The end of the Second World War and the defeat of Germany was in no way the end of the Jungmann. It was still very much in demand as a trainer and sport aircraft and significant production of it continued in Czechoslovakia, Spain and Switzerland in the years following the conflict. Spain was the last producer of the Bu-131 when the CASA assembly line made their last example of it in 1960.
Given the aircraft’s prewar success, wartime mass production and more than a decade of continued postwar production; it’s hardly surprising that the Bu-131 family tree is somewhat of a convoluted affair. Perhaps the best way to make some sense of it is to examine the nation by nation output of the type:
Germany
Four variants of the Bu-131 were made by German hands. The Bu-131 A,B and D versions were all production standard trainers set apart from each other primarily by the type of engine fitted to them.
The Bu-131 C was a single experimental machine fitted with a British made Cirrus engine.
Czechoslovakia
The first Czech built variant was the prewar Tatra T.131 which was built in very modest numbers before being discontinued.
The Aero C-4 was the designation given to the aircraft produced under German occupation and was built to the Bu-131B standard with a German engine.
The Aero C-104 was the designation for the type built in the post war period which was powered by the Domestically produced Walter Minor engine.
Japan
Two slightly different variants of the aircraft emerged from Japan, both fitted with domestically produced Hitachi engines.
The Kokusai Ki-86 was the Imperial Japanese Army primary trainer while the Kyushu K9W1 was the navy’s primary trainer. A small amount of K9W1 production was contracted to Hitachi.
At a total of roughly 1400 aircraft, Japan was the biggest producer of the Bu-131 outside of Germany.
Under allied code naming practices of the Second World War, Japanese training aircraft bore the names of trees. Both Japanese versions carried the allied code name of “Cypress”.
Poland
Polish production of the Jungmann is an interesting subject being as how the country did not have a hand in building the aircraft in the historic sense.
In the mid 1990s, working from Czech plans and using a Czech engine, new build Jungmanns started appearing under the designation T-131PA.
Polish construction is carried out by Air Res Aviation in Jasionka.
Spain
Spain’s CASA company produced the aircraft from 1938 to 1960 under the main designation, CASA 1.131.
The base CASA 1.131 which appeared in 1938 was powered by a German engine. Around 200 were produced before CASA switched to Spanish produced engines and created the 1.131E and 1.131L versions.
In the Mid 1990s, Bucker Prado used the CASA 1.131 construction jigs to build about 20 new airframes. These new built aircraft are known as the BP 131.
Switzerland
A total of 84 aircraft were built in Switzerland by Dornier-Werke for the Swiss air force.
Keeping Sharp in Retirement
Through the late 1950s and 1960s the air forces of Czechoslovakia, Spain and Switzerland began to retire and sell their Jungmann fleets to the public.
The reputation that the aircraft had built for itself as responsive and predictable in handling made it easy to sell to pilots looking for a competitive and proven aerobatic mount. Many of the aircraft that were sold found their way to America and underwent conversion that saw them fitted with a modern engine made by the Lycoming company.
Many pilots claim that the Jungmann is a superior aerobatics machine not only to comparable biplanes of its own era, but also against more modern types that followed it. Indeed, in the right hands, a Bu-131 could hold its own and sometimes prevail in competition over the Yakovlev and Zlín monoplanes which dominated aerobatics through the 1960s.
To be fair to the biplanes of the Jungmann’s era, there really is not a clear line of comparison between it and them. The DeHavilland DH-82 Tiger Moth and the Stampe SV.4 which are often considered the Bucker product’s closest contemporaries are really only passingly so.
Both the DeHavilland and Stampe aircraft were developments of older designs and retained elements of older design philosophies and methods, sometimes to their detriment. On the other hand, the Bu-131 was a completely new design when it first flew and as such took advantage of many more modern and refined design aspects than the other two could.
The Bu-131 Today
Thanks to a sizable production run that extended into the postwar era and a wide fan base among pilots which has fostered a support base to provide spare parts and servicing, the Jungmann has done very well for itself in retirement. There is said to be around 200 examples of the type still in existence between museum collections and active flyers.
Between the historic ones that remain and what newly built ones may fly out of Poland, it seems the Bu-131 is a shape that will be cutting its way through the skies for many years to come.
Learning More
The Bucker Pages website is a tremendous resource on all things related to the Bucker aircraft company.
Pickled Wings 