Under the project number 64 Tupolev, with Dmitri
Markov as chief designer, had begun to work on a
long-range strategic bomber in 1945. The arrival of the
B-29s and the subsequent Tu-4 programme put a stop to this project.
At the end of 1948, just as production Tu-4s were
beginning to be delivered to the VVS, Tupolev and
Markov began work on a replacement. In a sense, it
was an improved B-29 design, with a major
programme to trim weight and thus to improve
performance. Once again, the wing was raised (after
the Tu-70 and Tu-75) back to mid-fuselage position,
but a new wing with better aerodynamic qualities and
with a lighter but stronger spar was developed. The
fuselage was also redesigned; it was lightened and
the round Tu-4 nose of the same chord as the fuselage was replaced with a more usual one in which the
cockpit was raised above the nose for improved
visibility. A new, more angular tail was also built,
with a distinctive dorsal fin. Its engines were four
of Shvetsov's ASh-73TKFNs, a Soviet-built
turbocharged version of the original B-29 engines.
All these changes resulted in the Tu-80 being
substantially lighter than the Tu-4, and this allowed it
to carry more fuel. Its first flight was made on 1 December 1949 from Zhukovski. In state
tests, its maximum speed was established as 640km/h. But the Tu-80 was just another step
on the way to the Soviet Union achieving a long-range
strategic bomber. With the coming of age of turbines,
it was not developed beyond its test programme.
