 The Mikoyan @-@ Gurevich I @-@ 250 ( a.k.a. <unk> N ) was a Soviet fighter aircraft developed as part of a crash program in 1944 to develop a high @-@ performance fighter to counter German turbojet @-@ powered aircraft such as the Messerschmitt Me @-@ 262 . The Mikoyan @-@ Gurevich design bureau decided to focus on a design that used something more mature than the jet engine , which was still at an experimental stage in the Soviet Union , and chose a mixed @-@ power solution with the VRDK ( <unk> @-@ <unk> <unk> <unk> – air reaction compressor jet ) motorjet powered by the Klimov VK @-@ 107 V12 engine . While quite successful when it worked , with a maximum speed of 820 km / h ( 510 mph ) being reached during trials , production problems with the VRDK fatally delayed the program and it was canceled in 1948 as obsolete . 
