In the first half of the forties, aircraft manufacturers faced the question of the need to create new types of power plants, allowing to obtain high power with a relatively small mass. At that time, the use of liquid jet engines (LRE) on fighters looked very promising; the work was carried out in teams led by V.P. Glushko, L.S. Dushkin and A.M. Isaev. Already during the war years, a BI-1 fighter with an L-1A-1100 rocket engine was created. The first flight of this aircraft took place on 15 May 1942. By the time the war ended, the USSR had gained some experience in creating liquid jet engines.
Despite the presence of some serious drawbacks, such as excessively high fuel consumption, as well as the need to have onboard aggressive or unstable components (nitric acid, liquefied oxygen, hydrogen peroxide, etc.) as an oxidizer, the LRE also had positive qualities. He had a relatively simple design, while allowing him to get very significant traction, which, in addition, unlike the piston propeller group and air-jet engines, did not fall as it climbed, but even, on the contrary, increased slightly. This circumstance made the LRE attractive for creating fighter-interceptors, which would have high speed, high rate of climb and a practical ceiling, unattainable for aircraft with other types of power plants.
It should be noted that after the war, in the hands of the Soviet aviation specialists got a serially produced and used in hostilities German missile interceptor Me 163, equipped with a Walter NWK 109-509 LPRE with a thrust of 1750 kgf. Several copies of this aircraft were delivered to the USSR for comprehensive study and testing. True, unlike the Me 262, flight tests of the Me 163 were carried out only in the version of the glider, which was lifted into the air by the Tu-2 towing aircraft. The rejection of full-fledged flights was caused by the fact that the captured liquid-propellant engine did not undergo bench tests in the USSR, which would make it possible to give an opinion on the suitability for flight tests of any instance. Due to the lack of an appropriate test base in NII-1, only disassembly, drawing up diagrams and calculations of the German rocket engine were carried out.
As for the Me 163B, despite the aerodynamic scheme unusual for that time (tailless, equipped with a swept wing), the plane was easy to fly and was able to perform all the aerobatics, as well as ordinary fighters. Some difficulties arose only during take-off and landing, primarily due to the unusual chassis layout, which has a drop-off take-off trolley and landing skis. It was impossible to make a conclusion about the combat effectiveness of the Me 163 solely on the basis of the results of non-motorized tests, but the official German information on how to get 12000 meters by plane in 3,5 minutes and reach speeds up to 950 km / h at high altitudes made a strong impression.
The leadership of the NKAP was not eager to copy Me 163, but it also could not dismiss the problem of intercepting heavy high-altitude bombers of a new potential enemy. The specialists of the Air Force and Air Defense carefully studied the German experience in repelling American and British heavy bombers and could not help but note that the Germans had missile interceptors. Therefore, when developing a plan for pilot aircraft construction on 1946, the question was raised about creating the same type of aircraft in the USSR. As a result, the plan included two almost identical tasks for developing interceptors with rocket engines; for OKB A.I. Mikoyan (OKB-155) and OKB S.A. Lavochkin (OKB-301).
The maximum speed at the ground of the new OKB-155 aircraft should have been equal to 1100 km / h, at high altitude - 1000 km / h, ascent time at 17000 and 3,2 minutes, flight time: at the forced mode 5 minutes, at least 18 min, armament was provided from 2 guns caliber 23 mm, the period of the exit of the test vehicle for flight tests - November 1946 of the year.
By this time, OKB LS Dushkina achieved, perhaps, the greatest success by developing the most powerful LRE at that time in our country: in 1942, D-1А-1100, having 1100 kgf thrust, for BI, then in 1944 - RD-2М, which increased to 1400 kgf for the 302 aircraft. But these engines had low reliability. A.M. Isaev upgraded the D-1-1100 engine, especially in terms of improving reliability, and brought it to 1 hours. Under the new designation RD-1M he successfully passed state tests in 1945 year.
V.P. Glushko developed the RD-1 accelerator, which developed 300 kgf thrust, for use on Yakovlev and Lavochkin piston fighters and intended to create three-and four-chamber LREs with increased 3-4 thrust based on it. But these plans remained unfulfilled: with the beginning of the work on copying the V-2 FAU. Glushko was entrusted with the engine for her.
Meanwhile ls Dushkin created a new powerful two-chamber LRE RD-2MZV. This engine worked on kerosene and nitric acid. Its main feature was the presence of two cameras - a large one with a weight in 1100 kgf and a small one (300 kgf). This made it possible to take off and climb to height using the maximum thrust of the two chambers, and then disconnect the large camera and perform horizontal flight, target detection and attack using only the small camera thrust, while significantly saving fuel and increasing the flight duration.
Originally it was planned to install this engine on the Polykarpov interceptor “Baby”, designed as early as 1944. However, the sudden death of N.N. Polikarpov did not give the opportunity to finish the work. And now this engine was intended to be installed on new AI interceptors. Mikoyan and S.A. Lavochkin. On state tests of RD-2МЗВ, conducted in May 1945, the total thrust of two chambers was 1500 kgf, nominal - 1250 kgf and minimum - 500 kgf. The maximum thrust of the small chamber was equal to 300 kgf, the minimum - 100 kgf. The mass of the LRE assembly with units does not exceed 225 kg.
As soon as OKB-155 and OKB-301 took up the design, it turned out that TsAGI specialists could not give them anything new. Although the institute already had a variety of captured materials on German studies of high-speed aircraft schemes, including those with swept wings, TsAGI had to conduct a large complex of its own research and study everything itself, and only then make recommendations. It was absolutely necessary both from a technical and from a “political” point of view - it was far from safe to trust the documents of a recent adversary. The task was complicated by the fact that the TsAGI staff had at their disposal the only T-106 high-speed pipe with a flow rate of more than 900 km / h, and that was even more idle due to constant power outages. Construction of more high-speed pipes has not yet been foreseen. Therefore, it was decided to abandon the originally planned swept wing (20 °) in favor of the straight thin one. A similar decision was made in OKB-301. The lack of necessary experience among TsAGI specialists in this matter was also confirmed in the summer of 1946, when MAP considered the design of the AS jet aircraft. Moskalev.
In December, 1946 of the year in OKB-301 completed preliminary design and built an interceptor model that received the number "162". However, the expediency of the rocket plane caused Lavochkin great doubts, and he stopped work on this project.
At the same time, A.I. Mikoyan didn’t refuse to incarnate his interceptor missile, which received the I-270 code, in the metal. In fact, its development was launched in November 1945. The machine was intended for air defense fighter units that protect strategic civilian objects and military bases. By the beginning of April 1946, the layout of the interceptor, which received the factory name “aircraft J”, was developed, and the production of blueprints for the manufacture of the layout began. V.M. was appointed Lead Engineer for the new machine. Belyaev. After purging, TsAGI recommended lengthening the nose of the fuselage to give it a more aerodynamic shape. In May, the mock-up was ready, and a preliminary demonstration was held by its military representatives, who made a number of comments. According to the proposals of the military, the draft was finalized by the end of May 1946.
According to calculations, the missile interceptor was supposed to reach speed at ground level in 1000 km / h, at medium altitudes - 990 km / h, on 11000 m - 930 km / h and on 15000 m - 935 km / h. The height of the 15000 meters machine had to gain in 181,25 with. Practical ceiling - 18000 m. The maximum duration of the flight at high altitude was to be 4,89 min. Landing speed 137 km / h. In order to increase the duration of the flight, the MAP was bound by LS. Dushkina to make and carry out tests of LRE RD-2MZV with the resource increased to 1 hours. In 1946, the NII-1 planned to force the RD-2MZV thrust to 2000 kgf. It is worth noting that over time, the direct wing was still expected to replace the swept, this, according to the designers, taking into account the use of a forced engine, made it possible to achieve speed in 1100 km / h.
Two guns HC-23 with ammunition housed under the airtight cabin of the pilot. The pilot defended the front 8-mm armored plate and 15-mm bulletproof glass. On the plane was planned installation of an ejection seat for emergency escape of the aircraft by the pilot. Two combustion chambers of LRE RD-2MZV were located in the tail section of the aircraft, vertically. The total fuel and oxidizer supply was 2120 kg. Great attention was paid to protecting the I-270 structure from the destructive action of aggressive nitric acid vapors. Special acid-resistant fittings and anti-acid coatings were developed. All duralumin parts (anodically oxidized), located in aggressive zones, had several protective coatings, the number of layers of which could be up to nine.
According to the approved schedule for the development and manufacture of the “F” aircraft, the rollout of the first car to the airfield was planned for October 20 on the 1946 of the year. But due to the numerous reworkings of the interceptor project, only by October 2 the working drawings were completed and the bow assembly with the pressurized cabin was completed, which had to be tested in a thermocamera. By this time, began and tail tail statistics. In addition, the pace of work was significantly reduced, since the main labor force was seconded to the aircraft plant number XXUMX, to force the construction of the lead series of the MiG-1 jet fighter. Therefore, the deadlines could not stand.
Of the three planes built into the construction, two were completed. The first of these, “F-1”, brought 28 December 1946 to tests. Since the delivery of the flight copy of the LRE was delayed, a mock-up engine was mounted on the machine, which made it impossible to proceed with full-fledged flight tests, and they had to be divided into two stages.
During the first stage, “motorless”, the interceptor was towed by a specially equipped Tu-2 aircraft. For these flights, the X-NUMX made it easier by removing all unnecessary loads, including a mock-up engine, fuel tanks, fuel rocket power supply wiring and guns. The engineless testing of the Zh-270 aircraft began on February 1 3. It is necessary to say that the preliminary testing preceded the glider tests. In January, ground towing of the I-1947 with an uncoupling at speed was carried out, during which flights were carried out to a height of up to 270 meters, and on February 2 before the start of the first test phase, VN Yuganov performed a preparatory flight on a piston fighter Yak-3. The latter was also towed behind the Tu-9, and to obtain the characteristics of stability, similar to the calculated characteristics of the aircraft “Ж-2”, the car was loaded with lead blanks.
In non-motorized flights, the I-270 uncoupling with the towing vehicle was carried out at altitudes from 5000 to 7000 m, after which the test vehicle made a flight and landing plan. During free flights, the maximum instrument speed was reached, equal to 600 km / h, the minimum was 220 km / h. A total of 11 flights were performed in tow.
8 of May 1947 of the year on the second manufactured aircraft, which received the code W-2, was installed a flight copy of the RD-2MZV engine, which made it possible to proceed to the next stage of testing. However, on July 16 during the testing of the power plant on the ground a small camera exploded. The tail of the aircraft was damaged, and it was sent for repair, completed on August 2.
The first independent take-off of the second instance of the 270 took place at the end of the day on September 2 of the year 1947. The takeoff with the help of the liquid propellant rocket engine was made normally, the car gained 3000 m height, then following the mission, the pilot transferred the plane to the flight planner and began to build an approach. However, due to an inaccurate calculation, the landing was made outside the airfield, by the river. As a result, the first seven-minute flight was the last. The car was broken nose. Fortunately, the pilot was not injured. It was decided not to restore the car.
By this time, and on the first copy of the I-270 (F-1) mounted conditioned engine, and 14 August interceptor entered LII for flight tests. After completion of the preparation and ground testing, the 29 September was made taxiing, and five days later the first flight was made. However, on landing, the I-270 (F-1) did not get the chassis, and the test pilot VN Yuganov was forced to land the aircraft on the fuselage. Thanks to the skill of the pilot, the car received minimal damage.
The duration of the first flight was 12 minutes. The length and time of the takeoff, respectively, were 697 m and 20 s, the speed of separation 230 km / h. A large engine chamber was turned off via 130,5 s, when the aircraft was at an altitude of 4500 m. The speed was reached in 615 km / h at an altitude of 3000 m. Unfortunately, the failures continued. October 21 after the completion of repair during the launch of the LRE on the runway exploded a large chamber, with the result that the engine vomited nozzle. The aircraft was again sent to the repair, which was completed by the end of November.
At the beginning of 1948, the I-270 (M-1) completed all the preparations for its flight. However, further tests had to be suspended, since the operation of an acid-generating rocket engine in winter conditions was not worked out. After each departure, it was necessary to rinse the entire system with water, which was impossible to do in the cold. In addition, there was no weather for high-altitude flights. Therefore, A.I. Mikoyan in agreement with LS Dushkin was instructed to stop and stop the flights until the spring of 1948.
However, by that time, it became quite clear to the MAP leadership that the rocket engine, at that level of technological development, was unsuitable for normal operation in combat units of the Air Force and Air Defense, therefore, it was decided to focus on aircraft with turbojet engines, which was the last point in stories AND-270.
R. Belyakov, J. Marmen. I-270 Fighter // MiG Aircraft 1939 — 1995. M .: AVIKO PRESS, 1996. C. 56-72.
Bagratinov V. Wings of Russia. M .: EKSMO, 2005. C. 629-630.
Arsenyev E. Serov G. The Fighter I-270. Faster than all, above all // Aircraft of the world. 2003. No.1. C. 6-17.
Arsenyev E. The I-270 Fighter // Wings of the Motherland. 2007. No.11. C. 12-15.
Shavrov V. The history of aircraft designs in the USSR 1938 — 1950. M .: Mashinostroenie, 1988. C. 320-321.