Sergey Ilyushin had begun design studies during 1950–51 for a jet-engined ground-attack aircraft possessing better performance characteristics than was possible with piston-engined aircraft. By the end of 1951 the Ilyushin design bureau had prepared a technical proposal for a two-seat armored aircraft using two Mikulin AM-5 axial-flow turbojets rated at at maximum power (without afterburner) and with afterburner. In January 1952 Ilyushin sent this proposal to the government, which was quickly accepted, and he was directed to design and build one prototype.