The Soviet OKB of P. V. Tsybin constructed a series of LL (flying laboratory) high-speed research aircraft, including examples with a forward-swept wing. Perhaps knowing something of Lockheed’s U-2, the V-VS asked for an interception-proof reconnaissance aircraft to reach 3000 km/h (1,862 mph) at 30000-m (98,425-ft) altitude. Tsybin's contribution was the NM-1 (or LL 3) research aircraft, with twin AM-5 engines on the blunt tips of a stubby trapezoidal wing, and a very slim body carrying a normal tail. It was not especially fast, but intended to reach Mach 2.80 in a dive. During 1957 test pilot A-K Sultan flew the NM-1 as an unpowered glider (above, with tufted port wing for aerodynamic observations by chase aircraft), which was towed by a Petlyakov Pe-2. The aircraft later made ten powered flights, but it was considered (politically) a dangerous aircraft and, to some degree, overtaken by events, such as reconnaissance satellites..
