By a decree of the USSR Council of Ministers on 3 June 1953 of the year (the corresponding order of the MAP issued 8 June), the OKB-155 was commissioned to design and build an experienced I-3 front-line fighter (I-380) for the new powerful VK-3 engine, which was created in OKB B. J. Klimova with 1949 year. It was intended for installation on new Soviet interceptors, calculated on a maximum flight speed of the order of 2000 km / h, and practically became the first in the USSR two-circuit TRD with an afterburner. The first prototype of the aircraft, armed with three HP-30 cannons, was required to be submitted for state tests in the first quarter of 1956. According to the draft design, approved in March 1954, the maximum speed of the I-3 (I-380) during the afterburner with the take-off weight 8954 kg could be 1274 km / h near the ground, and at the height 10 000 m - 1775 km / h. Calculations were made with the condition that the VK-3 engine will have thrust at the nominal operating mode of 5160 kg, at the maximum mode - 6250 kg, at the oversage - 8400 kg.
The range and duration of the flight could be increased by installing two standard 760 l suspended tanks under the wing. The booking of the cockpit was foreseen: front armored glass 65 mm thick, front armored plate (12 mm), armor headrest (16 mm) and armored backboard (16 mm). The total estimated armor weight was 87,5 kg. The aircraft's armament consisted of three fixed wing cannon HP-30 with a total ammunition 195 shells (the capacity of the cartridge boxes allowed to place up to 270 pieces). Aiming was carried out with an ASP-5H optical sight, combined with the Radal-M radio range finder. In the overload in the fuselage could be installed retractable installation for firing uncontrollable projectiles APC-57 (their stock was 16 pieces). Instead of hanging tanks, it was possible to install two large-caliber projectiles of type TRS-190 or APC-212, as well as two 250-kilogram bombs. An experienced 3 was built, but it wasn’t lifted into the air due to the engine’s unavailability. However, many of the elements and design solutions worked out on it were embodied in the next OKB-155 aircraft.
The next series of experimental machines, created as part of the work on the front-line fighter, had the code "E". It is believed that the aircraft series "E" began to develop under the symbol "X", starting with the X-1. However, no evidence of this was found in the reports of the experimental plant No. 155 and in the correspondence of the OKB-155 with the customer and the ministry; the only thing that was discovered was the X-5 project. Let me assume that it was the only project with such a designation, and the figure 5 is nothing more than engine thrust in tons. Apparently, someone was confused by the designation "X", typical of American experimental aircraft. "X" is designated in the transcription as "eks"; It is quite possible that this is precisely what explains the choice of the letter “E” to designate promising OKB-155 machines.
Airplanes of the “E” family began to be created in accordance with the decree of the Council of Ministers of the USSR from 9 September 1953 of the year (on the same day, the resolution on the creation of TRD AM-11) was issued and the order of the IAP from 11 September “On the creation of a front-line fighter with a triangular wing of structure t Mikoyan ”, which, in particular, stated:
“In order to further improve flight technical data and assimilate the new fighter scheme, the Council of Ministers of the USSR by Resolution of September 9 of 1953:
1. He obliged the MAP (t. Dementiev) and the chief designer t. Mikoyan to design and build a single front-seat fighter with a delta wing, with one AM-11 turbojet engine designed by t. Mikulin with an afterburning 5000… ”.
The document prescribed that the maximum speed in the afterburner operation in the afterburner mode for five minutes was not lower than 1750 km / h at the height of 10000 m, the time it took to reach this height was 1,2 minutes, the practical ceiling was 18000-19000 m. The range was set at least 1800 and 2700 km when flying at an altitude of 15000 m without the use of afterburning in the TRD, and the length of run and run is no more than 400 and 700 m.
The plane was supposed to allow a steady dive dive using brake covers from all flight altitudes and turn on this mode. It was necessary to ensure the possibility of operating the fighter from unpaved airfields.
The plane required to install three guns HP-30, optical sight, coupled with a radio range finder; in addition, the machine was supposed to carry 16 rockets APC-57. About bombing weapons until the speech did not go. The first copy of the planned two experimental ones was required to submit an 1955 for March state tests, i.e. less than a year after the order was issued.
However, the engine destined for the new aircraft did not mature in time, and soon the chief designer of the OKB-ZOO was replaced. As a result, we had to install a less powerful AM-9 engine, which was naturally annoying, but not critical, because with the old engine it was possible to investigate the behavior of the machine in flight and then refine the design.
The designers had no doubts about the engine chosen for the prospective car; controversy erupted in determining the shape of the wing. The triangular wing specified in the resolution, although it was considered very promising, at the same time, concealed a lot of unknowns and had a high design risk. The general designer decided to insure himself by starting work in two directions - arrow-shaped and triangular.
Judging by the assignment, the machine was designed to combat low-maneuverable targets - bombers, since neither the rate of fire, nor the ammunition loaded with the guns planned for installation on the aircraft, did not allow an effective fight against enemy fighters. It seems that the experience of the war in Korea has not taught the “trendsetter” anything - the domestic Air Force. Or maybe someone “upstairs” saw the main threat in the bombers. Anyway, in the OKB-155 provided for installation on the fighter, only two guns.
Until July 1954 in the documents aviation you can still meet the designation X-5 in industry, but already in August there is a mention of the design of the E-1 aircraft, set by the resolution of the Council of Ministers of September 9, 1953, though with the AM-9B engine, which was used on MiG-19 aircraft. However, the E-1, designed with a triangular wing, did not leave the project stage. The reason was related to the difficulties in the development and research of the delta wing. A similar delay occurred in the OKB P.O. Dry when creating a T-3 fighter. For this reason, it was proposed in the first place to develop a swept wing aircraft. So the founder of a new family of aircraft was the E-2.
In February, by order of the Minister of Aviation Industry on an E-1955 aircraft with an AM-2 engine (perhaps it was a typo and should be read AM-9B) in February 9 was appointed as the test test pilot G.K. Mosolov (understudy V.A. Nefedov) and engineer A.S. Izotov.
The first flight of the E-2 took place on February 14 1954. The plane was installed wing swept 57 ° at the leading edge and the relative thickness 6%. To improve the takeoff and landing characteristics, slotted flaps and two-section slats were used. The roll control was carried out by a two-section ailerons. Subsequently, in order to exclude the reverse of the ailerons, which arose in some flight modes, interceptors were installed on the wing. The front edges of the shells of the frontal air intake device (OVC), by analogy with subsonic machines, were made semicircular, creating an additional suction force.
The press repeatedly mentions that on an airplane with an RD-9B engine the speed of 1950 km / h was achieved. This is a profound error. Apparently, this speed is calculated for the aircraft with the AM-11 turbofan engines and taken from the assignment for this car. Yes, and elementary calculations show the impossibility of achieving this speed. So that the reader does not have doubts, I will give an example: the CM-12 / 3 aircraft, possessing approximately the same flight mass and twice the thrust-to-weight ratio, developed a maximum speed of 1930 km / h. In January, the first E-1956А / 2 aircraft (in 1, someone in the GACT or Design Bureau assigned it the designation MiG-1957) with the РХNUMX-23 TRD was transferred to the factory for testing. Converted from the E-11, the plane stood for a year waiting for the engine. A distinctive feature of this machine were aerodynamic partitions (crests) on the wing, which were absent from the predecessor. The first flight on this machine was performed by test pilot OKB G.A. Sedov 300 February 2 g. The leading engineer for the car at the stage of factory testing was AS Izotov.
E-2A tests were very difficult. The machine was characterized by a longitudinal buildup, due to defects in the layout of the control system, increased sensitivity to small deviations of the control knob for a roll at high indicator speeds. It took a lot of time to eliminate the defects of the power plant, because of which the machine was 11 months in a non-flying state. In addition, it was necessary to fight with the shaking, found when flying at high speed at low altitudes, and with lateral buildup.
Six months later, the second E-21А / 2 machine arrived from factory No. 2, which on the last day of December, OKB-155 presented to the Air Force Scientific Research Institute for state tests. On this machine, in 1956-1957, they performed 107 flights (on both planes - at least 165 flights), which made it possible to remove all the main characteristics. Both pilots also flew industry pilots V.A. Nefedov and A.P. Bogorodsky. After working out the resource of the engine and equipment, the aircraft were written off as unnecessary. During the tests on the E-2 with a flight weight of 6250 kg, the following indicators were achieved: the maximum speed of 1950 km / h (M = 1,78), the ceiling - 18000 m, the climb time 10000 m - 1,3 minutes, the range - 2000 km. The armament consisted of two HP-30 cannons and two jet guns suspended under the wing with APC-57 unguided missiles. For shooting was used aiming ASP-5H. Bomb armament was also envisaged.
The third type of aircraft of the "E" series was the E-4 with a delta wing, until the release of the government document was developed, as noted above, under the designation X-5. In April 1954, the draft design was defended.
As in the cases with the E-2 and E-50, the RD-11 engine had to be installed instead of the standard Р300-9 instead of the standard Р1955, and the beginning of the flight tests with the standard TRD was transferred from March 1956 of the year to August 5. determine the flight characteristics of the future E-9. 1955 June 4 of the year by the order of the GCAT on the E-4 was appointed the leading pilot G.A. Sedov (understudy V.A. Nefedov) and engineer V.A. Mikoyan. A week later, Grigory Alexandrovich performed the first flight on E-XNUMX.
Initially, on the plane, as on the T-3, there was a clean wing, made up of profiles TsAGI-C 9, but with aerodynamic partitions - one on the lower surfaces of the consoles, approximately in the middle. Apparently, at TsAGI, the true picture of the flow around triangular wings was still poorly represented, and that was what the trial and error method was moving forward. The E-4 actually became a flying laboratory, where they investigated the influence of various ridges on the aerodynamic characteristics of the wing (the studies were continued on the E-5). The aircraft during the tests reached a maximum speed of only 1290 km / h. In 1956-1957, X-NUMX flights were performed on E-4, having fully developed the engine and equipment life.
9 January 1956 test pilot Nefedov made the first flight on the following prototype with a delta wing, the E-5 with the TRX Р11-300 - the aircraft that received the designation MiG-21 a year later. V. Mikoyan remained the lead car engineer. Apparently, Dementiev and Mikoyan 2 on April 1956 reported to Khrushchev about reaching 30 in March 1810 km / h speed at 10500 m, and in the CPSU Central Committee and the government attached great importance to this. But this value was not the limit: on May 19 in flight at an altitude of 11000 m, the speed reached 1960 km / h, which corresponded to the number M = 1,85.
Thus, the test results perplexed even the most experienced, most experienced: the triangular wing did not bring any great advantages, the obvious gain, and the question unwittingly arose whether it was worth trying to master the garden trying to master this wing? In the office of Mikoyan gathered leaders KB. The first word was given by the chief designer to testers. However, for the pilots, it is indisputable for now a little - the car with a delta wing accelerated a little faster, and at the expense of a larger supply of fuel, it had a slightly longer range.
Even having built and tested aircraft with different wings at the same time, it was not immediately possible to make a decision. Artem Ivanovich came to watch the flights of both cars more than once, talked with pilots, engineers, delved into all the details. Any of such trifles could tip the scales in one direction or another.
At the same time, designers studied the situation in world aviation, analyzed materials of the aviation press, identifying the trend, the main direction of development.
Americans deafened noisy advertised fighter F-104 "Starfighter". Its chief designer, Clarence Johnson from Lockheed, the creator of the infamous U2 spy plane, chose for Starfighter a seemingly very small, straight trapezoidal wing, driven out of high-speed aviation, with an extremely thin profile. and a pointed front edge (radius of a rounding of a sock of 2,45 of cm). This wing has extremely low lifting force. To provide more or less acceptable take-off and landing characteristics, Johnson equipped the machine with deflected wing toes throughout the span and large slat flaps with a large chord .. At about the same time, the third high-speed fighter, the development of which was widely discussed in specialized journals— “Mirage” with triangular, like the future of the MiG, wing - began to develop the French designer Marcel Dassault. So who is right? Americans or Dasso, whose position coincided with the position of Mikoyan?
Having investigated the capabilities of a plane with a straight wing, Mikoyan did not believe in its prospects. The choice remained only between the swept and delta wing. The final choice between them in favor of the latter was made by the customer. Summarizing the test results, we began to build the latest prototype of the future MIG21. Called this pre-production machine E6. And the E-2 remained in the discharge of the experienced ones, since the serial plant in Gorky built only seven E-2А aircraft.
List of used literature:
Mikhail Arlazorov “This timeless MiG-21”
Efim Gordon "Non-standard MiGs"
Nikolay Yakubovich. The birth of a legend
History designs of aircraft in the USSR 1951-1965
Yefim Gordon. Birth of a long-liver
Rostislav Vinogradov, Alexander Ponomarev “Development of World Airplanes”