Myasishchev DVB-102

The Myasishchev DVB-102 was a long range, high-altitude bomber of which only two prototypes were built. It's origins can be traced back to 1939 when the Soviet Government foresaw the need for a long-range bomber.
The aircraft was proposed by Vladimir M. Myasishchev, main chief engineer of his own aircraft design bureau in the USSR. Its design was approved in early 1940 and in June the construction of the prototype began. The DVB-102 was developed simultaneously with other projects like the high-speed interceptor DVB-100 (a design that never went beyond the drawing board), the Petlyakov Pe-2 or the Tupolev Tu-2 and the Tomashevich I-110.
One year later, in summer 1941, the first fuselage was complete and so static tests began, however due to the quick German advance, the factory where the works were taking place had to be displaced so it wasn't until spring 1942 that the first prototype was ready for flight testing.
Due to bureaucracy and war shortages, in winter 1942 the first prototype was brought to the VVS' (Soviet Air Force) airfield to be tested. It was powered by two Klimov M-120TK engines which yielded, each of them, a power of 1.800 hp and were equipped with TK-3 turbocompressors. After having been test flown, construction of a second prototype began.
In fall 1943, the prototype was handed back to Myasishchev to be improved, as there were many flaws detected by the VVS. However, by that time, the factory was dedicated to manufacture the Petlyakov Pe-2 (some of them being modified) and, many new variants, with many engines, were designed, however only one seemed factible: the one powered with M-71 engines and TK-3 compressors, which, in fact was flight tested in high-altitude tests during March to July 1944-1945.
It was defensively armed with two 20 mm ShVAK cannons, one in the nose and other one in a dorsal turret plus one 12,7 mm BK machine gun placed in a remotely-operated ventral position. The theoretical payload was of 2.000 kg (4.409 pounds) with an overload of almost 4.000 kg. When tested it achieved an altitude of 11.500 m (37.729 ft) high with a theoretical range of 3.600 km (2.236 milles) powered by a M-71F engine.
However, the M-71F engine showed poor numbers, specially regarding maintenance and performance and, on 20th July 1945 during a test flight one of the engines failed, and, due to the lack of replacements for such engine, combined with the study of the more promising Tupolev Tu-4 (the Soviet copy of the B-29), lead to the mothballing of every Myasishchev's aircraft at Frunze Central Aerodrome, and, eventually scrapped. In 1946 the OKB-482 (Myasishchev design bureau) was closed, but in spite of the requirements of the VVS, the bureau wasn't restored until the 1950s and their previously designed aircraft were quickly forgotten.
Some of the ideas applied to the DVB-102 were however, applied to later designs like the Ilyushin Il-22 or Il-28.

Sources:
1. https://www.globalsecurity.org/military/world/russia/dvb-102.htm
2. http://www.aviastar.org/air/russia/mjas-102.php
3. https://www.secretprojects.co.uk/threads/myasishchev-aircraft.779/