Mikoyan-Gurevich MiG-15 (NATO reporting name: “Fagot”) is a jet fighter developed for the Soviet Union by Mikoyan-Gurevich OKB. MiG-15 was one of the first successful swept-wing jet fighters, and it achieved fame in the skies over Korea, where early in the war, it outclassed all straight-winged enemy fighters in most applications. MiG-15 is often mentioned along with the North American F-86 Sabre as among the best fighter aircraft of the Korean War and in comparisons with fighters of other eras. MiG-15bis is an improved MiG-15 version; the main difference is the improved engine, the Klimov VK-1.
Its level speed at sea level was increased by 26 km/h to 1,076 km/h. Noticeable change is a huge improvement of thrust-to-weight ratio which increased the acceleration by ~10% and it also has a huge impact on its climb rate, it can reach up to 50 m/s at low altitude with full fuel tanks, making the MiG-15bis one of the best climbing planes compared to other planes at similar battle rating. It is now better at performing vertical loop and other similar maneuvers because of the better engine. But new engine has more fuel combustion rate, and less internal fuel tank capacity to reduce flight endurance or range.