First afterburning turbofan in URSS, under development at OKB-117 since 1949. Designed for speeds up to 2000 km/h, estimated thrust 5160 kgp at nominal power, 6250 kgp at full military and 8400 kgp at full afterburner. Tested in I-3U in July 1956, good performances but poor reliability, modified in December 1956 with new compressor blades, ended his career in January 1958 alongside the airplane. Maybe "killed" by the less modern but more efficient Lyul'ka AL-7F.