Theoretical speculation on the effectiveness of the use of swept wings for greater speed confirmed. The acquired results have been applied in the design and construction of new fighter jets, two of which — La-15 and MiG-15 — to mass creation at the end of 1948.
But to break the sound barrier (and this may pose a particular task), a wing sweep of 35 degrees would not do — the resistance was very large. To reach this number, sweep required to bring at least 45 degrees, increasing the traction motor. TsAGI necessary wing developed, but the pipe T-106 did not provide the ability to test this wing at speeds of more than M = 0.9. Management TSAGI designers give advice on installing new wing aircraft are not solved.
At the end of 1946 it all cleared up, and it becomes clear why the Khrunichev finish building an experimental aircraft «4302» did not want to — it has required a completely different plane. And at the same time — it’s time to get rid of unwanted complainants and transfer the case to a more «pleasant» for the heads performer. In the former fiefdom Bolkhovitinov — factory number 293 MAP formation of a new experimental design bureau headed by Bisnovatyi. Despite the fact that he was specifically Bisnovatyi glider designer «302» sadly famous KOSTIKOVA, apparently, a minister in his competence did not hesitate.
Bisnovatyi were given an assignment to create a modern experimental aircraft aerodynamic configuration to study its characteristics in flight and master the technique of flying at speeds up to M = 1.1. The plane, which was designated a «5» should have been a promising wind-swept wing assembly with 45 degrees. and profiles TSAGI P2 (2M) and 12045bis. Propulsion aircraft was forced liquid rocket slider RD-2MZVF (Designer Dushkin) with a thrust of 2 million kg, because as long as there was a massive (especially at a great height, where it is easier to reach the speed of sound).
Because it is always limited in store fuel, the plane «5» takeoff and climb to 10 thousand meters had to be towed for specials. aircraft-towing, then uncoupling occurred and the inclusion of liquid-propellant rocket motor. It was assumed that the aircraft is not counting the greatest rate of M = 1.1 will have: a climb from 10 thousand to 15 thousand meters — 68 sec., At the highest thrust duration of the flight — 2.5 min., While performing the task — 3 min. On the plane to safety had to be installed pressurized cabin pilot, discharged in an emergency situation and the air brakes. Formally approved the new plan, the task of experimental aircraft 11/03/1947.
To increase security and reliability, it was decided to build the research work and experience in actual flight unmanned scale model copy of the aircraft. In the short term this model, which has received index «6», made in the factory number 293 with the SEZ TsAGI (manager Vadim Kuznetsov Design Bureau). Model to scale 1:2,75, equipped with liquid-propellant rocket engine, the U-400-10 with a thrust of 400 pounds, design Isaev. To control the flight used autopilot AP-14.
Model «6» has been suspended from the bomber Tu-2 and was rising by 9 thousand meters, then dumped, and in a straight coast with a running jet engine was to develop a supersonic speed. By calculation, the rate was to be M = 1.225. For the recording of the flight characteristics of the model was equipped with recording equipment. For a touchdown after the end of the motor had quite an easy automatic parachute system, which includes alternately produced by the wing brake parachutes. After they produced a tail drag chute (1 m2) and the main parachute (100 m2).
Stalingrad at the airport «Gumrak» during the period from September to November 1947 were flight tests of the aircraft model «6». Just launched four copies.
During the launch of the first model (№ 61), she quickly picked up speed, went to TU-2 and La-7 — aircraft escort — and was lost from sight. In the upcoming model number 61 is not found.
After uncoupling the second model (№ 62) were significant variations around the transverse and longitudinal axes. In the acid backbone has been an air pocket, which led to the fact that after 8 seconds. came off early rocket motor. Model number 62 safely descended by parachute. The speed of its flight was only 230-240 meters per second.
Model number 63 worked well, but after 44-45 seconds. the motor suddenly she ran across a dive, and the braking parachutes broken. Crashing into the ground, it went into the ground to a depth of about 5 meters. Film recorders COP-4 and MC-7 were damaged and VH generally not detected. For the measurement of the MC-7 dynamic pressure, it was assumed that it received a straight flight at an altitude of 8.3 million meters, it was stated that speed have gained Model M = 1.28 (1405 km / h).
Solo flight fourth model (№ 64) lasted 51-52 seconds, with little self-excited oscillations about the transverse axis. After the end of the motor main parachute did not open. The plane fell on the tail wing and brake parachutes and went to 800 mm into the ground. Records of all devices, except VH which was absolutely destroyed, deciphered. For the remaining records, said that during the flight speed of the model was M = 1.11 (1,230 km / h).
Plane «5» under the wing of the Pe-8
The acquired data were given the opportunity to consider the MAP that the models develop a speed befitting the design and tests carried out on the whole successful.
Command of the Air Force did not agree with that. In January 1948, he wrote Vershinin NA Bulganin minister of the armed forces: «… With regard to research by flying models (designer friend Bisnovatyi), the tests have shown that their nedorabotannost, from the standpoint of aerodynamics model and obtain impartial flight data to draw any practical conclusions are not it is probable and can be considered only as a first attempt to use the flying models for the study of speeds in flight . » Even the question open a discussion about making 20 more advanced models, and repeated tests, ensuring the safety of all entries devices. It’s not been realized, as has already been completed construction of the first airplane flight standard «5» («5-1»).
The scheme of take-off in tow was replaced suspension to the plane-womb. The carrier served as a bomber Pe-8 number 42911, to which an experimental aircraft «5» hang up on a farm under the wing. Delayed delivery of the motor, and therefore experience a first prototype of the aircraft «5» began in July 1948 in the glider version. This was done to investigate the flight characteristics of aircraft at low speeds. Piloting the aircraft «5» engaged Colonel Pakhomov, and the carrier Pe-8 run test pilots Samusev and sheriff.
No problem, there were some in this time. First flight, which took place on July 14, ended in tragedy caused by the jammed elevator. The downside was corrected. Second flight with a cutaway held on September 3 was advantageous, but found a transverse instability of the aircraft — spontaneous inclinations and low effectiveness of the ailerons eliminate them. It was decided to carefully study this phenomenon in the 3rd flight, which took place on September 5, but the landing was a tragedy again. A small transverse swinging after touchdown run across in the shots from the 1st to the other wing, with which the pilot was unable to cope. The plane, burying his nose fractures. The pilot was not injured.
It concluded (deputy chairman. Laboratory chief TSAGI Matveev), the premise of the tragedy was the missing lateral stability at low speeds when issued landing flaps, inflated friction in the management of the ailerons, the wrong approach the earth, and partly degraded visibility due to fog lamp. It was recommended to alternate with the elimination of all these shortcomings, to change the underwing arc on the heel or crutches and to blow into a tube model of the Central hydrodynamic Institute.
All these factors pushed away by getting the desired result «5», but the situation changed again. In 1947, at the urging of a determined air forces and with the help of the Moscow Committee Party control of MAP have been made for efforts to build a high-speed wind tunnels. TsAGI during the second half of the year in order entered tunnel T-112. Size of working area works were small — 700×600 mm, but the flow rate was already supersonic — M = 2. However, the pipe was still not enough experimental equipment, but it allows us to refine the scheme of the wing of 45 degrees.
In 1948, the Lavochkin design bureau has established a streamlined wing of an experimental aircraft «176», at first kitted TRD NIN, and later — the VC-1.
December 26, 1948 Captain O. Sokolov, the test pilot plant number 301, for the first time in the USSR in flight with a decrease officially headed for Mach 1.0, and in January of the next year and slightly exceeded it — M = 1.016 — 1.03. During level flight received a number M = 0.99. Although the plane 3 February 1949 crashed (the cause of the tragedy is not connected with the aerodynamics — during takeoff opened lantern and Sokolowski made the wrong decision), the merits of the speed of sound puzzle solved. The wing sweep of 45 degrees obtained the right to mass deployment.
Ahead of the new frontiers emerged. Built a second copy of the «5-2», and in 1949 took flight in glider version (G.M.Shiyanov — FRI test pilot, Hinze and Chistyakov — pilots support the Pe-8). But subsequent work on the aircraft are no longer current. Realizing that the motor of the rocket plane flights are pretty risky, management has decided MAP quietly close this formulation tested method — its funding was discontinued in 1949.
As a result, the plane «5-2», with committed 01.26.1949 to 09.06. 1949 glider flights and nine in the period from October to November, four more tests with the engine never started. The plane has been tested on the ground and installed on the aircraft.
Airplane «5» after the tragedy
Bisnovatyi did not protest and started doing other tasks. Risk of complaints came not only from the remaining lot developer liquid rocket engine, which was the OKB-1 Dushkin logged by the time of the Central Institute of Aviation Motors. This risk management MAP tried to neutralize and ventured in January-May 1949 analysis of the OKB-1.
The reason for the analysis were the «signals» of workers OKB-1 of abuses during the bench in 1947 by state. Test engine RD-2MZVF, including by Dushkin. It was fought on the substitution in the process of testing the defective parts without the knowledge of the state commission that vosprepyadstvovalo identify resource engine. By decision of the board of the IAP chief designer was a serious reprimand and warning, three workers were laid off, and the documents were handed over to them by the investigating authorities. Eight employees EDO also fired.
During 1949, the «minimization» CB Dushkin continued. OKB-1 stands for the judgments of safety shut down, did not give new jobs, and the former were not funded. Office of the Central Institute of Aviation Motors raised the question of the elimination of OKB-1. Transfiguration and lumps, workers bureau, wrote about all that the Secretary of the Central Committee of the CPSU / b / GM Malenkov returned by the time of opals. In February 1950, made a special commission of the MAP, which included MV Keldysh, LI Sedov, Chesalov AV, Polar AI Kolosov and EI. They were instructed to investigate the work of a seasoned CIAM. The Commission concluded that the bad state of work on liquid rocket engines for aviation experiences on subsequent reasons:
«Despite the fact that until now still in the air as if there is no clear concept of introduction of liquid rocket engines, the main designers issued a huge number of jobs (to varying degrees have developed subsequent oxygen engines RD-ES-1 (pull 1,500 kg), RD-KS 3 (3000 kg thrust), RD-COP-5 (thrust 5000 kg), the nitrogen engine RD-ZM (3000 kg thrust), Oxygen Accelerator US-2500 (2500 kg thrust — approx. Creator).
In the OKB-1 was the practice of underestimating questions about the safety and reliability of the motor.
The result indicated circumstances where liquid missile engine mounted on a seasoned model airplanes, work on these aircraft stopped unfinished, or for reasons of futility of combat aircraft applications, or in connection with the tragedies caused by bad motor work …
According to the views of the Commission for Aviation today there is no definite prospects for introducing liquid rocket engine …
Existing studies suggest that liquid rocket engine may get used in aviation as a stand-alone motor for interceptors that act on the heights of more than 20 thousand square meters only after the exhaustion ability of turbojet engines, follow them turbojet engine and ramjet engines.
At the same liquid rocket engines can be used as auxiliary — boosters or boosters in flight … «
The Commission recommended the continuation of work on the air in the liquid rocket engines to Mape, but very limited scope of this paper and prove the issue of jobs. This, in essence, was a veiled sentence for rocket engines and rocket planes. Earlier engines have made a negative assessment, get a new job as well as it should, and the funding of these criteria has become virtually impossible. But the aircraft without engine can not be built.
Officially work to create a Russian rocket engines for aircraft were shot CM Decree number 2473-973 on 06/10/1950. OKB-1 of CIAM was liquidated personnel were transferred to the bureau Glushko, a laboratory rocket engine, and other laboratory branch of the Central Institute of Aviation Motors.
Aircraft performance properties of an experimental aircraft, «5»:
Length — 9.92 m;
Wingspan — 6.40 m;
Wing area — 11.18 m2;
Empty weight — 883 kg;
The biggest take-off weight — 3184 kg;
Motor type — liquid-propellant rocket engine RD-2M-3VF;
Rod — 1610 kg;
The highest speed — 1200 km / h;
Crew — 1 person.
Based on materials from the website airwar.ru