In 1938 A.M.Lyulka who was working in Kharkov aviation institute (KhAI) in a team developing steam turbine for A.N.Tupolev heavy bomber, worked out a design of a turbojet RTD-1 with 500kg thrust with one- or two-stage centrifuge compressor driven by a gas turbine.
The characteristic feature of that engine was relatively low turbine inlet temperature (650-700°C). The implemented design decisions and thermodynamic parameters of the RTD-1 ensured that it could be developed in relatively short time using construction materials fully mastered by that time by the industry.
Estimations made by A.M.Lyulka showed that a single-seat fighter powered by the RTD-1 engine could reach the speed of 900km/h....The order adopted by the Defence Committee of the USSR's Council of People's Commissars [then the name of the Soviet Government] on 12 July 1940 the necessity to continue the work on the turbojet engine of A.M.Lyulka's design was stressed with the aim to test the engine on a test rig already in December 1940.
In the war years the work on development of A.M.Lyulka's RTD-1 engine continued.... In 1943 under the leadership of M.I.Goudkov (one of the designers of the known LaGG-3 piston-engined fighter), a variant of the LaGG-3 powered by the RTD-1 engine was being designed. The engine was to be installed in the "step" layout at the bottom of the fuselage with jet exhaust under the tail [Yak-15 look-alike]. The maximum speed of the modified LaGG-3 was estimated at 900km/h.