The Tupolev OKB continued to develop the Tu-2 line with the advent of gas turbine power-plants. The Tu-8 was redesigned with two Rolls-Royce Nene I turbojet engines, replacing the piston engines in new nacelles. The new design was given the OKB designation '72' and official designation Tu-18 2 × Nene I, but was abandoned due to the more promising '73' design soaking up resources. Following the general arrangement of the Tu-2- Tu-8, '72', the initial '73' short-range bomber had a shoulder mounted wing, a large unswept fin and rudder with integral dorsal fin, tri-cycle undercarriage and engines in long under-slung nacelles at about 1/3 span, which also housed the main undercarriage legs, when retracted. Before the design was finalised it was discovered that the Nene I engines were producing less power than expected; and not the expected, necessitating the addition of a Rolls-Royce Derwent Vbooster engine in the rear fuselage, exhausting at the base of the fin. The three-engined '73' was accepted for development and the '73' first flew on 29 December 1947, with flight tests continuing until 31 May 1949, with promising results, resulting in a production order for ten '73S' pre-production prototypes, powered by RD-45 and RD-500. None of the pre-production order were completed but parts manufactured at GAZ-23 were absorbed by the Tupolev Tu-14production line at GAZ-39. Further development of the '73' line resulted in the photo-reconnaissance '73R' / '78'. The '78' was outwardly identical to the '73' with the exception of a retractable conical shutter over the intake of the rear fuselage Derwent at the forward end of the dorsal fillet. The '78' first flew on 7 May 1948 and conducted flight trials of the photographic equipment, which were unsatisfactory. Improvements to the photographic equipment notwithstanding the Council of Ministers cancelled all further development or production of the '73', '78' and '79' on 14 May 1949. Two more phot-recce projects were designed both similar to the '73' and '78'. The first '79' was not proceeded with. The second '79', was to have utilised an uncompleted '73S' airframe but development was cancelled as noted above. The VVS rejected the three-engined bombers as they were averse to fielding aircraft with two engine types. They were also more in favour of the Ilyushin Il-28 for medium bomber roles. The AV-MF, however, were in need of a torpedo bomber which was developed from the final '73' iteration, the '81 as the '81T'. Production aircraft were delivered to the AV-MF as the Tupolev Tu-14T.
Variants
Data from: OKB Tupolev: A History of the Design Bureau and its Aircraft ;'72': Initial project for a tactical bomber powered by two Rolls-Royce Nene I turbojet engines, derived from the Tupolev '69', not built. ;'73': Initial shortrange bomber project, powered by two Rolls-Royce Nene I turbojet engines, not built. ;'73': experimental bomber project, powered by two Rolls-Royce Nene I and one Rolls-Royce Derwent V turbojet engines, one built. ;'78': Reconnaissance version, powered by Rolls-Royce engines, one built. ;'79': initial project for a photo-recce aircraft based on the '73' ;'79': '78' powered by Klimov VK-1 Soviet-built Rolls-Royce engines. Originally designated '73R'. ;'81': Twin-engined medium bomber development of '73'. ;'81T': Twin-engined torpedo bomber development of '73' for the AV-MF.
