Tupolev Tu-73 - The ‘73’November 23, 2011 0 Comments
The Tu-72 was developed as a naval bomber in 1946/47. It was to be a mid-winged, twin-engined aircraft without sweep, and the engines were due to be hung under the wings. Rolls-Royce Nenes were the chosen powerplants, but Air Force worries over the adequacy of two engines to power an aircraft of this size and weight led Tupolev to design a similar, but slightly larger aircraft, the Tu-73, with a third engine, this time a 1600kg Rolls-Royce Derwent, fitted in the tail but with an air intake noticeable at the front of the fin in what would become a classic feature of trijets twenty years later. While design work of both aircraft continued in parallel, it was the three-engined Tu-73 that was actually built.
Its first flight was made on 29 December 1947. It went well. During state tests, its performance was measured as top speed 870km/h, range 2,800km, and service ceiling 11,500m.
The Tu-74 (or Tu-73R) was a proposed photoreconnaissance version which was not developed.
The Tu-78 and Tu-79 were essentially the Tu-73 but with Soviet licence-built Rolls-Royce engines. The two Nenes were now called the RD-45, and the Derwent, the RD-500. The prototype was built at factory N 156 with Sergei Yeger in charge. It made its first flight on 17 April 1948 and its state tests were completed by December. It was approved for serial production under the VVS designation Tu-20, but this was not actually carried out because of the shortage of production facilities. The Tu-20 designation would be used again later.
The Tu-79 was a long-range reconnaissance aircraft originally designated Tu-73R. By then, 1949, Klimov had developed the Nene/RD-45 to produce 2,700kg thrust, and the Tu-79 was to have been fitted with two of these VK-1 engines in place of the lower powered RD-45s. The VVS allocated the designation Tu-22 to planned production. Although this one was never actually built, the Tu-22 designation would also be used later.