Plane number “302”
A fighter with an unusual power plant, consisting of one upper-stage liquid-propellant rocket engine and two ramjet engines with rectangular controllable nozzles under the wing, a normal cantilever low-wing aircraft according to the design. Under the tail there is a L.S. Dushkin RD-1400 liquid propellant engine with a thrust of up to 1400 kg, under the wing there are two ramjet engines designed by V.S. Zuev. There are two ShVAK cannons in the nose of the fuselage and two of the same under the cockpit, and under the wing there is a retractable suspension for two PCs or FABs. This was the aircraft according to the 1940 project, conceived as the world’s first fighter with a composite jet group. It was developed by a group of engineer M.K. Tikhonravov under the general leadership of A.G. Kostikov - at that time the chief engineer of the RNII (NII-3). In the spring of 1941, the project was reported and approved by the technical council of the institute. After defending the project at the VVA commission, A.G. Kostikov sent the project to the NKAP, where on July 17-18, 1942 it was approved by the commission: S.A. Khristianovich, A.V. Chesalov, S.N. Shishkin, V. I. Polikovsky and others. In the second half of 1942, A. G. Kostikov introduced K. E. Voroshilov to the project. On the same day, at a reception with Stalin, the “302” project was approved, and Kostikov himself was appointed Chief Designer of OKB-55 and director of the pilot plant. M.R. Bisnovat became the head of the OKB , and A.A. Andreev became the deputy. V.D. Yarovitsky was invited to perform strength calculations, and M.K. Tikhonravov was in charge of aerodynamic calculations. By the spring of 1943, the production of Zuev ramjet engines was behind schedule - they were completed only in the form of half-life-size models and did not undergo full testing. The Dushkina D-1-A liquid-propellant rocket engine with a thrust of 1100 kgf with an additional chamber of 450 kgf was not yet ready and had just begun fire tests. Therefore, they decided to equip the 302 fighter only with the RD-2M two-chamber liquid rocket engine. Since the development of the liquid-propellant rocket engine was delayed, it was decided to test the fighter in a glider version, designated “302P”. The weapons and some equipment were removed from the aircraft, and a mock-up of a single-chamber liquid-propellant rocket engine under the fairing was installed in the rear fuselage. At the end of August 1943, he entered testing at the LII. Flight tests revealed not entirely satisfactory stability characteristics, and the 302P was sent to TsAGI, where it was tested in a full-scale wind tunnel. During purging in the T-104 TsAGI pipe, aerodynamic quality K = 15 was achieved. After modifications, the aircraft was comprehensively studied in several dozen flights in tow behind the Tu-2 and B-25. According to S.N. Anokhin’s flight assessment , the “302P” aircraft was exceptionally stable and controllable in all axes, glided well, performed “barrel rolls,” and was easy to land after uncoupling from the towing vehicle. M.L. Gallai , who was on the “302P” flyby, called the car a “standard”. A similar assessment was given by the second flyby pilot B.N. Kudrin
and leading testing engineer V.N. Elagin. The landing speed of 115-120 km/h set during testing corresponded to the normal landing mode of the interceptor. There were no motorized flights due to the unavailability of the rocket engine. The structure of the aircraft is wooden, the wing (RAF-34 15% profiles at the root and NACA-230 8% at the ends) and tail with plywood sheathing, the fuselage is a monocoque. The plane was very clean and pleasant to fly. The landing gear was retracted by a hydraulic system. The first version of the power plant (LPRE and 2 ramjet engines) assumed the highest speed “302” - 900 km/h, ceiling - 9000 m and its climb time - 2 minutes. Calculated data of “302P”: ground speed 800 km/h, ceiling - 18,000 m (?!), climb to altitude 5000 m - 2.1 min, 9000 m - 2.8 min, flight range - 100 km. Only the take-off run was realistic, 16-18 seconds and a take-off speed of 200 km/h. With 400 rounds of ammunition for 4 guns, 505 kg of fuel and 1,230 kg of oxidizer, the empty weight of the aircraft was 1,502 kg and the take-off weight was 3,358 kg.
Armament
Cannons 4 x ShVAK-20
Bombs or RS, pcs. 2
So the 302P is just a plane with rocket engine while normal 302 is rocket + 2jet engine + armament