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.
A new wing with better aerodynamic qualities and with a lighter but stronger spar was developed with integral wing tankage. The fuselage was lightened and the round Tu-4 nose of the same chord as the fuselage was replaced with 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.
Engines: 4 x ASh-73FN, 1770hp
Max take-off weight: 67200 kg / 148151 lb
Empty weight: 41030 kg / 90456 lb
Wingspan: 44.3 m / 145 ft 4 in
Length: 36.6 m / 120 ft 1 in
Height: 8.91 m / 29 ft 3 in
Wing area: 173.1 sq.m / 1863.23 sq ft
Max. speed: 650 km/h / 404 mph
Ceiling: 11180 m / 36700 ft
Range: 7000-8000 km / 4350 - 4971 miles