With early MiG-15s having several deficiencies, the MiG OKB quickly developed an improved variant, the MiG-15bis, powered by the improved Klimov VK-1 engine, and equipped with larger air brakes to prevent the jet from exceeding the speed of Mach 0.92, at which control surfaces became ineffective. Series production began in 1950, and large numbers were quickly rushed into service with the Soviet air defences. Like the MiG-15, the bis was easy to maintain but not the easiest aircraft to fly. Moreover, its armament was ill-suited for air combat against high-speed and manoeuvring targets like the US-made fighter jets encountered during the Korea War – where, in 1952, this example may have been flown by Semyon Fedorets of the 689th Guards Interceptor Aviation Regiment, credited with seven aerial victories. (Artwork by Tom Cooper)