Combining a fuselage essentially similar to that of the Lavochkin La-168 with wings sweptback 45° at quarter-chord and several other aerodynamic refinements, the La-176 was flown in September 1948 with a 5004-lb / 2270kg RD-45F turbojet, and armament comprising one 37mm N-37 and two 23mm NS-23 cannon.
Re-engined with a Klimov VK-1 turbojet of 2700kg, the La-176 was claimed to have exceeded Mach=1.0 in a dive from 9050m to 6000m on 26 December 1948. It was initially believed that an ASI error had been involved, but the process was repeated six times during January 1949, 1105km/h being recorded at 7500m, this being equivalent to Mach=1.02. The La-176 thus became the first Soviet aircraft to achieve supersonic flight. Further development was abandoned shortly afterwards when the canopy locks failed at high speed, resulting in test pilot Î V Sokolovsky losing his life.
Max take-off weight: 4631 kg / 10210 lb
Empty weight: 3111 kg / 6859 lb
Wingspan: 8.59 m / 28 ft 2 in
Length: 10.97 m / 35 ft 12 in
Wing area: 18.25 sq.m / 196.44 sq ft
Max. speed: 1043 km/h / 648 mph
Range: 1000 km / 621 miles