The Ural-Bomber programme was issued with secret talks with the main German aircraft manufacturers, as back in 1933, the Treaty of Versailles was still in force, requesting them some designs for a long range bomber. The submitted designs were the Dornier Do.19 and Junkers Ju.89 respectively and prototypes for both aircrafts were ordered by the RLM (Reich's Aviation Ministry) in 1935.
Both aircraft proved to be promising, but when Wever died in a plane crash in 1936, his successors, Ernst Udet and Hans Jeschonnek, favoured smaller aircraft as they didn't require so much matherial and manpower, so the big bomber programme fell into disfavour. Udet and Jesschonnek were also the proponents of the close air support doctrine which advocated for attacking opposing forces on the battlefield rather than destroying enemy's industrial power. They convinced Hermann Göring about the need of Tactical Bombers acting in the army support role. Göring's beliefs proved to be right at the Battle of France, but it was the lack of Luftwaffe's Strategic Bombing capabilities the factor that hampered Germany in the Battle of Britain.
Back to the Ju.89, the first prototype was flown on 11th April 1937 by Hesselbach, it was powered by 4 Daimler-Benz DB600A engines rated at 560Kw (750hp) each and was going to be armed with 2 20mm MGFF cannons placed in a dorsal turret and another pair placed in a gondola above the fuselage. It was expected that additional defensive 7.92mm MG15 machine guns would be placed in the rear, front and even in the back of the cockpit making four the number of defensive light machine guns. However, just two weeks later of the first flight, on 29th April, the strategic bomber programme was cancelled by the RLM due to the high fuel consumption of heavy bombers and because bombers could only be manufactured in large numbers if they were medium ones, like the Junkers Ju.88.
However, a second prototype was manufactured in July 1937 and both of them were used by Junkers to learn about the stability and flight controls on large aircrafts. A third prototype was being manufactured but it was cancelled when the programme was cancelled.
On 4th June 1938, the Ju.89 achieved a new payload/altittude world record with 5000kg (11000lb) at 9312m (30500ft) outnumbering its most likely British counterpart in those pre-war years, the Short Stirling. Later, on 8th June 1938 the second prototype achieved an altittude of 7242m (23750ft) with a payload of 10000kg (22000lb). In late 1938 both aircraft were transferred to the Luftwaffe which used them as heavy transports.
Apparently both prototypes were scrapped in late 1939, however, some sources claim that they were still in active service in Norway during 1940. When it was being tested, Lufthansa expressed their interest in an airliner variant of the type and that leaded to the third prototype to be completed as the Junkers Ju.90.
Sources:
1. https://en.wikipedia.org/wiki/Junkers_Ju_89
2. Luftwaffe Secret Projects - Strategic Bombers 1935-1945
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