Tsybin RSR

The Tsybin RSR (Reactivnyi Strategicheskii Razvedchik) was a Soviet design for an advanced, long-range, Mach 3 strategic reconnaissance aircraft.

Development and design
In 1954, the design bureau headed by Pavel Tsybin started development of a ramjet powered strategic supersonic bomber, the RS. This design proved impracticable, and a smaller derivative, the 2RS was proposed, which would achieve intercontinental range by being air launched from a modified Tupolev Tu-95 bomber.

This too was unsuccessful, with the aircraft unable to return to base if used on an intercontinental mission, while being incapable of carrying a thermonuclear bomb. The design was therefore revised again to a reconnaissance aircraft capable of operating from conventional runways, the RSR. As ramjets could not be used for take-off, they were replaced by turbofans.

The RSR was primarily of aluminium construction, with a long circular section fuselage, which housed a pressure cabin for the pilot together with cameras and fuel, with thin, low aspect ratio trapezoidal wings. The engines, two Soloviev D-21 turbofans, were mounted at the tips of the wings. The aircraft had a bicycle undercarriage, with outriggers under the engine nacelles. It was planned to cruise at greater than Mach 2 at a height of 20,000 m (65,600 ft) giving a range of 3,760 km.

A simplified, full sized aerodynamic prototype for the novel layout, the NM-1 was built in 1957. Intended for low-speed handling tests, the NM-1 had a steel-tube fuselage with duralumin and plywood skinning. This aircraft, powered by two Mikulin AM-5 turbojets first flew on 7 April 1959. Based on the results of these trials, the RSR was redesigned (as the R-020) to make it more manoeuvrable at high altitude (it was proposed to carry out barrel rolls to avoid Surface-to-air missiles, reaching a maximum altitude of 42,000 m (138,000 ft) during the manoeuvre). More conventional Tumansky R-11 turbojets (the engine used in the MiG-21) replaced the unavailable Soloviev turbofans. Five R-020 airframes were virtually complete, only awaiting engines by April 1961, with another 10 planned when Soviet Premier Nikita Khrushchev cancelled the program.