The work on the CAM-4 Sigma project was not in vain. 1937-07-05 the bell rang in the office of the director of the aviation technical school, which I occupied.
- Kaganovich M. M. will speak with you.
The conversation was unexpected and short, but very agitated me. Kaganovich, in an energetic form characteristic of him, began to clarify questions about the Summa (Sigma) project, did I offer this car? Having received a positive answer, he ordered to come to him in Moscow tomorrow. The "Voronezh Arrow" arrived in Moscow at about 8 am, and at about 9 o'clock, having settled in a hotel, just in case, I was at Glavaviaprom. It turned out that the "Sigma" was remembered due to the request of the People's Commissariat for Foreign Affairs, Comrade VM Molotov. - to understand and report on the essence of the information received about some foreign works related to the unusual shape of the wing (Glukharev's work in the United States).
The request of the Central Directorate of TsAGI - to explain what it was about - did not give anything useful. TsAGI scientists were not interested in unusual aircraft layouts. Almost half a year passed and Stalin became interested in this issue, who rightly believed that it was probably about something important and new in the field of aircraft technology, which he was very seriously involved in. After the request of Stalin's secretariat, it was impossible to delay the answer. Here II Mashkevich, the head of the Experimental Department, remembered the Sigma project, the wing shape of which reminded him of the sketches of the wings, which were given in the request. The Sigma aircraft project was reported to the head of the GUAP, and I was summoned to Moscow.
In the chapter, I spoke in detail about the aircraft project. He expressed my convictions in the real possibility of creating aircraft of such a configuration, equipping them with a rocket engine in the process of increasing their flight speed.
First Mashkevich Osip Osipovich, head of the experimental department, and then Kaganovich M. M. listened to my explanations very carefully. Then I presented all my considerations in the memo. Having discussed during a narrow meeting, at which the presence of TsAGI representatives, the issue of "Sigma" Kaganovich M. M. reported to Stalin. After the report, Stalin ordered to prepare a special order, in which I was asked to develop a draft analogue of the Sigma aircraft as soon as possible, build it in OKB-31, and conduct flight tests. TsAGI was instructed to conduct experimental studies of the aircraft model I developed in a wind tunnel. In addition, TsAGI was entrusted with independent work on the development of a glider with a low aspect ratio wing. The development of the glider project and its construction were entrusted to Kamemostsky, the designer of TsAGI.
The commander-in-chief, for some purpose, received two Renault 4 pi engines with a capacity of 140 hp that had just arrived in Leningrad. with. It was decided to use these engines for a light experimental aircraft. Glavaviaprom also decided to give the aircraft the name "Strela", since the shape of the aircraft resembled the shape of an arrowhead, and the telegraphic address of OKB-31 had the same cipher. Up to two and a half months were allotted for the development of the project and the construction of the aircraft, which was dictated by the long delay in the response from TsAGI and the interest of Stalin.
Here in Moscow, I developed a draft design of the Strela aircraft. For this purpose, I was presented at TsAGI with the vacant office of Professor Cheryomushkin, as well as draftsmen and copyists. The work was completed in a few days. The general layout was immediately agreed with Viktor Pavlovich Gorsky, a senior researcher at TsAGI, who was entrusted with conducting experimental research on Strela in a wind tunnel. During the layout of the aircraft, the shape of the Summa aircraft wing was retained, however, the usual VHO was installed at the ends of the wings instead of washers.
My considerations on the Strela aerodynamic layout, confirmed by experimental research at the Aerodynamic Laboratory of the Voronezh University of the Sigma aircraft model, were agreed with VP Gorsky, who, having familiarized himself with the idea underlying the project, became interested in the Strela aircraft. In the future, Gorsky provided significant assistance in the work, especially during the tests of the aircraft in the air.
Naturally, the conditions that were necessary for the construction of Strela dramatically changed the situation in the aviation technical school. The work of the OKB, connected with the acute regime of the new task, had to be isolated from the rest of the work.
Having reported at a meeting of the main employees of the Design Bureau about the receipt of a new assignment, which we met with great interest, we began to work. For the sake of completeness, it should be noted that at TsAGI, working with the Strela model, in terms of their experience and pace, required no less time than was given to work in full. Therefore, having agreed with Gorsky, it was decided to carry out work on the construction of the aircraft and purge the model in parallel: this decision was helped by the consultation of Professor Kochin. The Experimental Department of the Main Directorate agreed to this, taking into account the considerations of Kochin and Gorsky about the sufficiently scientific substantiation of the decisions made on the layout, tail size, aircraft alignment, and the like.
The construction of an aircraft without preliminary purging of the model at TsAGI in 1937 was not common, but the tight deadlines required this decision.
Two and a half months later, the plane was built, the necessary statistical tests and calculations were carried out. At the same time Gorsky V. P. aerodynamic blowing of the model at TsAGI was completed.
The materials of the model blowing made it possible to clarify the calculation of stability, aerodynamic calculation, the position of the center of gravity and the dimension of the tail. The experimental research program was far from sufficient for modern requirements. Lateral stability blowing could not be performed, there was no influence of the ground on the polar, there was no distribution of loads over the tail and wing, and so on.
A pleasant result of the blowdowns was that the aerodynamic calculation and blowdowns matched, the centering did not need to be moved anywhere, the tail was chosen correctly and the aircraft did not need to be altered. This was not accidental, because in the work on "Summa" and "Arrow" serious research studies were carried out with the involvement of scientists from Voronezh State University.
It should be noted that already at that time I was part-time head of the Aeromechanics Department at the Physics and Mathematics Department of the Voronezh State University, where there was a strong staff of young scientists. They helped me solve the most difficult aerodynamic problems of an unusual aircraft.
The strength tests of the aircraft were carried out according to the standards developed by the OKB. After weighing and determining the center of gravity, even before the arrival of the state commission, the plane was sent to the airfield, which is an alternate airfield for heavy bombers, located 10 kilometers from Voronezh, near the highway towards Zadonsk.
After my return from Moscow, where I was due to the high-speed races of light aircraft, on July 27 we began ground tests of the Strela. The tests were carried out by test pilot A. N. Gusarov, who went to work at the OKB at the end of 1936.
The car perfectly obeyed the pilot, at low engine speeds, it steered briskly, easily turned around, with the tail raised it kept the "straight line" well and quickly picked up speed. According to the pilot, after gaining speed of 70-80 km / h, the plane began to "ask for air".
The factory commission, except for Gusarov and me, consisted of the following OKB workers: Polukarova L. B., Zavyalov S. A., Maretsky N. A. and Dolgov. The state commission for flight tests arrived from Moscow in early August. She studied the presented documentation and decided to start the first tests, which included weighing, centering, taxiing and approaching. Since there were no strength standards for Strela-type aircraft, the state commission authorized Professor V. N. Belyaev. consider the calculations of the strength of the structure, materials of statistical tests and give an opinion on the admission of the aircraft to flight tests for strength.
Belyaev V. N. gave a positive conclusion. The calculations and results of research in the field of aerodynamics were also not in doubt. It was assumed that the flight tests will be carried out by the famous test pilot Boris Nikolayevich Kudrin "on account" of which there were tests of some unusual aircraft: tailless, parabolas, with swept wings, variable geometry wings and the like.
Kudrin walked around Strela for a long time. I looked closely, talked with A. N. Gusarov, watched the calculations, purges, thought about it and finally decisively declared to the commission that he would not only fly, but even fly up in such a strange machine, which, in his opinion, had neither tail nor wings, is not going to. He also added that by agreeing to go to Voronezh, he expected everything from the aircraft designer, but not this.
Attempts to persuade Kudrin to at least taxi the plane were unsuccessful (perhaps Kudrin's intractability was explained by the fact that he was close to Yakovlev and tested his machines quite often). Subsequently, Kudrin told the factory pilot that after the first glance at the Strela, he developed an irresistible aversion to the machine. According to some indications, the commission, represented by its chairman, the head of TsAGI, Protsenko, would have willingly abandoned this case, if not for the constant calls from Moscow.
In order not to waste time, after the debate, the commission decided to entrust ground tests to the factory pilot Gusarov, who had already taxied on the Strela and willingly agreed to taxiing and approaching.
Taxiing tests began again, as well as jogging with a raised tail. The tests were successful, except for one unexpected incident. During one of the taxiing, the pilot abruptly "kicked" and the car, which was taxiing at a relatively low speed, unexpectedly rolled over the wing, finding itself on its back. The plane lay, supported by the engine hood, the wing console and the keel. Due to its low speed and soft grassy ground, the aircraft did not receive any damage and everything ended in fright. The plane was turned over, put on wheels, the engine was started and the pilot drove it to the parking lot, where the car and its parts were inspected again. This incident made a strong impression on the commission.
The issue was immediately discussed and it was decided to make a steel rim out of the chrome-power pipe, including it in the rim of the pilot's lantern (no matter how strong the keel is, but just in case it is better to insure the pilot's head as well). And so it was done. Finally we decided to start flying. The first flight on August 7, 1937 was made by the pilot Gusarov. In Voronezh, the weather was fine and sunny. There was practically no wind. In the morning, at about 10:30, the pilot taxied the car to the edge of the airfield, and the commission was stationed near its center. Gusarov was supposed to make the first flight near the commission. After the usual formalities and obtaining permission from the chairman of the commission Protsenko, the pilot A. N. Gusarov. "gave" gas and the car quickly picking up speed began to take off. Raising the tail of the plane, the pilot delayed the separation, since the commission was far away, and, gaining a speed of 150 km / h (possibly more), pulled the handle towards himself. Before the eyes of the dumbfounded commission, which was 15-20 meters from the flying plane, the car soared into the air and at a height of 15 meters quickly began to roll to the left until the planes were vertically to the ground. Everyone froze in anticipation of a disaster. A moment passed, which seemed like an eternity, and in the next moment the pilot eliminated the roll and the plane, having flown almost to the end of the airfield (about 1200-1500 meters), easily and smoothly lowered onto the runway in its normal position, that is, by 3 points. The pilot, having completed the run, turned the plane around and taxied to the commission, which was wiping off the cold sweat. Coming out of the plane and unscrewing part of the helmet, Gusarov reported to the chairman of the commission about the successful test. After that, he became interested in the opinion of the commission on the approach.
On the impression of Gusarov himself, the approach went well and did not cause any concern in him. This is how, according to the pilot, the approach took place: “The commission was very far from the start of the takeoff, and the plane picked up speed faster than I expected, the approach had to be delayed, due to which the take-off speed was too high. broke off and almost instantly gained a higher than it should, height. After the lift-off, there was a reaction of the propeller and the car received a significant roll. After that, I threw off the gas, corrected the roll, pulled the handle and the car landed normally. According to the pilot, everything was fine. The plane takes off easily, perfectly obeys the rudders, what else is needed?
However, for the majority of the members of the commission, who observed the approach from the side and expected various surprises from the plane, such an approach did not seem normal. At the first moment of separation it seemed that the car would roll over onto its back. In fact, if the ailerons were not effective enough, and the pilot was experienced enough, had he been late with the roll response canceling, the approach would have ended in disaster. Pilot Kudrin B. N. tried to explain all this to Gusarov. In the end, he told him: "to fly in this car is like licking honey from a razor, if you want - fly, but I do not advise." At first, Gusarov could not "understand" why everyone was so worried? The commission, having considered the approach in a calmer atmosphere, decided to continue testing the Strela in Moscow. They found a lot of reasons for this, especially since Gusarov, frightened "in hindsight," refused to fly. In order not to waste time, it was decided to send the plane to Moscow on a five-ton tank, since the aircraft was easily accommodated in it. And so they did. We looked at all the roads and bridges on the map, packed the plane in a tarpaulin, prepared security and under the guidance of flight mechanic A. S. Buzunov. "Strela" went to Moscow to the TsAGI Research Institute, which was located at the Central Aerodrome. "Moving" the plane to Moscow from Voronezh was not easy, this was later reported by Buzunov and his entourage. However, the Strela was delivered quickly and safely.
In Moscow, after the report to the Chief Directorate of the Commission, it was decided that Strela's flight tests would be conducted as research tests. They were assigned to TsAGI. Clarified and expanded the composition of the commission. The tests began from the very beginning and before the implementation of the first two flights, they were carried out at the Central Aerodrome near the Dynamo station, where the helicopter station is located today.
After a second study of the documentation, they resumed taxiing. Despite the fact that the test pilot had not yet been appointed - there were no volunteers - there were a lot of people who wanted to steer. All LIS test pilots tried to steer - Rybushkin, Rybko, Chernavsky, Korzinshchikov and even N. F. Kozlov, head of the LIS. Famous air force test pilots and plant pilots, including Gromov, Alekseev, Stefanovsky, Chkalov and others, were often present during the tests. Some of them also tried to steer and expressed their own opinions about the car. For example, after taxiing, Gromov said that "the plane is asking to be in the air, but somehow there is not enough courage to lift it off the ground, what if it flips onto its back?" Chkalov inserted his own remarks into these arguments. All the pilots agreed that the plane steers perfectly, confidently maintains a straight line, and also clearly asks for air, but there were no people willing to take the car off the ground. And since no one agreed to make an approach, everyone began to persuade Gusarov to try again to tear off the car very carefully, at least a little, so that the gap between the ground and the wheels was visible. Gusarov, after a rather long resistance, finally agreed, since the tests had reached an impasse.
This time, Gusarov's approach was indeed carried out very carefully. Those present at the same time, especially the pilots, lay down on the ground and lower their heads down, watched the approach, trying not to miss the moment of separation. Then they argued for a long time whether the car came off or not, or it just seemed. This forced Gusarov to make another approach. Gusarov could not stand it and tore off the car by almost a meter, having flown a certain distance. He even checked the action of the ailerons. The question became clear - the plane lifts off the ground, flies, obeys the rudders and nothing bad happens to it.
After Gusarov, other pilots - Rybko, Rybushkin, Chernavsky - began to test the plane for approach. After that, the question arose again - who will test the plane? The young, but very capable TsAGI test pilot Rybko N. S., who suddenly became very interested in the aircraft, undertook to conduct the tests. Rybko received an aviation technical education (graduated from the Moscow Aviation College), so it was easier for him to understand model blowdowns, aircraft calculations, and also to connect them with the flight characteristics of the Strela aircraft.
After Rybko was approved by the Strela test pilot, systematic tests were started. Rybko, starting with small flights, brought them to long flights. Keeping the plane above the ground after taking off, he flew up to one kilometer or more, evaluating the behavior of the plane and checking the actions of the rudders. According to him, the car easily lifts off the ground, perfectly obeys the steering wheels and lands well. Having carried out, in his opinion, a sufficient number of such flights, Rybko announced on August 27, 1937 that he could make a flight. August 28 was an excellent summer day, a small breeze was blowing from the direction of Tushino. On this day, the commission decided to carry out the first flight of the Strela aircraft. The car was driven by N. S. Rybko.
They decided to take off in the direction of Vsekhsvyatskoe-Tushino, that is, away from Moscow. There, if necessary, you can find a place to land. In the same direction was the airfield of the Central Aero Club, and there were no large buildings.
After a short take-off run, the plane picked up speed, easily pulled away and almost immediately, with a jerk, gained an altitude of about 15-20 meters. But then, for some reason, the rise practically stopped. Some time passed, and the plane reached the edge of the airfield. Having flown over 5-storey buildings and tall pines, almost hitting them, the plane disappeared from sight. It became clear that the car was not gaining altitude and the pilot was not going to return to the airfield. There was silence for a while, everyone was expecting something. Then they suddenly began to act. Someone ran up to the P-5 plane and tried to start the engine, someone got into an ambulance, someone ran to the phone and started calling somewhere, and so on. The imagination painted horrors. But a few minutes later a phone call came from the Aeroclub airfield. Rybko reported on the safe landing of the Strela aircraft. Soon the commission met at the Tushino airfield and listened to the story of Rybko N. S. about the first flight of "Arrow". Here's what he said:
“After giving gas, the car quickly picked up the required speed. Slightly tightening the takeoff run, smoothly pulled the handle. The plane easily took off, quickly gained 20-meter altitude. At first I was worried about the roll, but after straightening it from the reaction of the propeller, I began to set the climb angle. However, I found that the height did not gain further. Thinking what to do next? It was scary and unusual to increase the angle of attack at such a low altitude, turning back is also dangerous - it is not known how the plane will behave. Therefore, I paid all my attention to overcoming obstacles on the way and reaching the airfield in Tushino. Carefully turning the car around with a pancake, I took the plane to the Tushino airfield, where I landed. The landing was also unusual, after the gas was removed, the plane began to descend vigorously and just before landing it was necessary to give gas to compensate for the rate of descent. After landing, I saw an open, empty hangar and, taking advantage of the agility and small size of the aircraft, taxied right there."
Rybko, having closed the hangar, sat down by a barrel of sand, lit a cigarette. He did all this very quickly and on time, since the people who were at the airfield and had nothing to do with Strela rushed headlong to the hangar to see what had landed at the airfield. Many saw the entire landing of Rybko, in particular, the famous designer of unusual aircraft "parabolas" B. I. Cheranovsky, who was at the airfield. and test pilot Shelest I. I. This is what he writes in his book From Wing to Wing:
“Rumors about something new in aviation are passing surprisingly fast. Somebody will suddenly start talking about some previously unknown pilot with pride and warmth. This is how I first learned about Rybko Nikolai Stepanovich, when he once landed at the airfield of the Central Club, literally falling on his head …
His apparatus at that time was very outlandish. Perhaps, only now, after the Tu-144 and "Analog", he would not have caused surprise. Imagine a long tailless, shaped like a very sharp triangle. Something like the "monk" or paper arrow that we used to launch when we were kids.
Rybko took off from Moscow from the Central airfield. The car turned out to be naughty, did not want to gain altitude at all. The plane flew in the direction of Tushino and, having passed Serebryany Bor, forced Rybko to land, since there was an airfield ahead. We surrounded the curiosity with great interest. We saw a lot of different gliders and airplanes, but something like that - never!
The unusual design of the aircraft and the pilot's courage made the witnesses of this case respect Rybko."
After the arrival of the service personnel and the commission, the Strela was wrapped in a tarpaulin, loaded onto a car and sent to the Central Aerodrome.
The pilot's message about the lack of the vehicle's ability to climb very much puzzled the commission. Attempts were immediately made to give a scientific explanation for this phenomenon. The opinion was expressed that an airplane having a shape like that of "Strela" cannot be considered an airplane, that it is very much influenced by the proximity of the ground, which improves the aerodynamic characteristics of the machine. An air cushion helps the aircraft to lift off the ground and gain a small height, and then, when the influence of the earth disappears, the aircraft with such a shape is not able to gain altitude. Of course, aerodynamics familiar with the blowing model were not involved in these speculations. From aerodynamic calculations, it followed that the car should have a sufficiently large ceiling. However, what is the matter? I, Konchin and Gorsky began to ask the pilot about the flight with "passion". How the flight was carried out, how the car behaved and what Rybko did.
It turned out that the pilot, after taking off the aircraft, had no time to estimate the angle of attack, but after gaining an altitude of about 20 meters and eliminating the aircraft roll, which caused the main concern, the pilot established his usual climb angle of attack. The angle at that time was determined by such a reference point as the projection of some noticeable detail onto the horizon. The climb angle was usually between 7 and 9 degrees. Rybko was guided by approximately such angles. It was here that the climb stopped. We all started looking at the aerodynamic calculations together and saw that it should be so. There is no excess power at these angles of attack for Strela, and the most optimal angle turns out to be almost twice as large. Everything fell into place. They scolded themselves for not paying the pilot's attention to this feature of the aircraft.
It was reported to the members of the commission, who were in complete confusion due to pressure from various advisers, mainly pilots excited by someone. All the pilots demanded to stop testing Strela, not to waste time in vain, not to risk the lives of the pilots, but to report to the government that a machine of such a layout does not have the ability to fly far from the Earth, that it can only be lifted off with an air cushion, that Rybko's first flight is clean accident and luck that it did not end in disaster and so on and so forth. Finally, the highest flight altitude to be reached by an airplane during a test is 30 meters.
They began to look askance at me, some even hinted at sabotage. The accusation of sabotage at that time was quite simple. The aerodynamics of TsAGI, while the debate about the further fate of the Strela aircraft was underway, began to study the nature of the flow. We glued the ribbons and began to blow the propeller of a large aircraft, photographing the behavior of the ribbons (photographs of the blowing and the report on the flight tests of the aircraft are in the archives of the Ministry of Aviation Industry and TsAGI). This period of testing was very difficult for me. An atmosphere of hostility was created, both towards the aircraft and its designer.
Leading engineer of TsAGI Yezhov many years later said that someone all the time made attempts to interfere with the tests of "Strela". Test pilot AP Chernavsky, recalling the Strela in his letter to the Chkalov Voronezh Aviation College in 1976, wrote: “We simply did not have time, or, more precisely, we could not perceive the Strela aircraft psychologically. We were not ready to work on this type of machine! You cannot blame us for that, you just had to understand us! Biplanes with braces, racks and suddenly a graceful swift triangle!"
Fortunately, test pilot Rybko NS was not only a pilot. The knowledge that he received at the aviation technical school allowed him to independently understand the features of the aerodynamics of the machine. Great efforts to continue testing Strela were made not only by me, Kochin and Gorsky, but also Rybko, which largely resolved the issue of further tests. When the test pilot figured out what was going on, he fired up interest in the tests and insisted on the expediency of their continuation. The arguments and persuasions of ill-wishers did not work on him. The decisive question was the request "from above" about the state of work with "Strela". The commission decided to repeat the flight.
Even before the new flight, Rybko demanded that a device be installed in the cockpit that would help him determine the climb angle. In the workshops of the LII, a suitable, albeit primitive, device was immediately made. It was installed in the cockpit. Before the flight, Rybko sat in the cockpit for a long time, got used to the new position of the landmarks, raised and lowered his tail, and finally announced that he was ready to try the car in the air again.
It was early autumn - September 1937 in the yard. The weather for the tests was excellent, as they say, "Indian summer". A spider web flew over the runway, and outside the runway there was drill training for students of the VIVA named after Zhukovsky. They all saw the flight of "Strela" made by test pilot NS Rybko. Colonel-engineer, retired Semenov N. K., a former student of the Academy, perfectly remembers the flight and the moment when the line of students broke down, stopping to observe the flight of this unusual aircraft. The direction was the same as during the first flight.
The plane was examined again, the pilot tested the engine, and the flight sheet was signed. Finally, the test pilot asked to remove the pads from under the wheels and began the takeoff run after the flag flapped. A few seconds later the car broke away and Rybko, after a short exposure, gradually began to increase the angle of attack. The plane obediently climbed upward with an unusually raised nose. After climbing 1200-1300 m, the pilot began to turn. At first, carefully, and then more and more energetically. Rybko began to test the Strela. He did slides, turns and everything else that was supposed to be during the first flights, and was in no hurry to land. Then the pilot "gave up" control, and the plane confidently continued to fly in a straight line, swaying around its longitudinal axis by 5-7 degrees. The swaying in the glare of the sun was clearly visible. The car went to land at a fairly high speed. Having a good speed reserve, the pilot easily landed at 3 points. Thus ended the second flight of the Strela and the first normal flight of the aircraft, which turned out to be quite successful. Further flight tests of the Strela, after several flights, were carried out on Lake Pereyaslavskoye in winter, and then again in Moscow.
Based on the test results, the TsAGI commission established the possibility of successful flights of an aircraft of such an unusual scheme for that time at subsonic speeds and also revealed the peculiarities of its piloting.
These were the tests of the world's first aircraft with a delta wing of low aspect ratio (L = 0.975). Now it was up to the achievement of supersonic flight speeds.
The only comment of the commission was small lateral vibrations of the machine when the control was abandoned, which for some reason were considered a feature of this scheme.
My absence from the commission did not allow me to draw its attention to the fact that the vibrations of the aircraft are well known and are called the "Dutch step". Their elimination is not particularly difficult.
The Strela aircraft was returned to the OKB in August 1938. A detailed report, conclusions and conclusions on the scheme arrived with the plane.
According to the conditions of the regime, the car, packed in a box at our request, was sent to plant No. 18 by rail. We decided to eliminate the aircraft defect discovered by the commission - lateral vibrations. Now we know that aircraft with swept wings have so much lateral stability that it is necessary to make large VOs and negative transverse "V" of the wings. For our case, there was a partial shading of the WMO. Without wasting time, the following activities were carried out:
- WMO increased by 30%;
- mounted washers of the "Sum" type.
Pilot Rybko N. S. soon arrived at the plant to carry out additional tests of the "Strela" at the airfield of plant # 18 in Voronezh. Heavy rains did not allow this. Later, AN Gusarov also performed excellently on Strela's test flights.
As a result of these flights, it was found that with an increase in the VHO, the oscillations were completely eliminated and when the washers were installed, they appeared insignificantly. We also determined the effect on fluctuations in the flight regime. In both cases, there were no oscillations at high speeds. According to the latest factory tests in Voronezh, the pilot A. N. Gusarov, after installing the Ratie propeller, reached a speed of 343 km / h. This speed was obtained at the measured kilometer of the plant # 18.
The aircraft "Strela" fully fulfilled its task, after all tests, drawing up an act, as well as writing an appendix to the TsAGI report, according to instructions from Moscow at the end of 1938, it was destroyed. The story of Strela did not end there. You will learn its continuation further. You will learn that with the outbreak of the war in 1941, under the leadership of designer Bartini R. L. developed a project of a supersonic fighter "P" of the "Flying Wing" type of small aspect ratio, having a large variable sweep of the leading edge, with a vertical two-fin tail at the ends of the wing.
The Bartini fighter was influenced by the Sigma aircraft design and the successful tests of its counterpart, the Strela aircraft.
In the development of the project, Bartini R. L. VN Belyaev, a former member of the state commission for testing the "Arrow" in 1937, took part. The "R" project developed by Bartini remained on paper. The P-114 (an aircraft with a swept wing) developed by Bartini in 1943 was also not implemented. R-114 is a good jet interceptor with a liquid-propellant jet engine designed by Glushko. But BI-1 of the design bureau of V. F. Bolkhovitinov passed. clearly not suitable for high speeds in its layout (in this regard, test pilot Bakhchivandzhi died).
In 1944, at the end of the Second World War, the Germans, creating their own jet aircraft, will also attempt to use the "Strela" scheme for their supersonic fighter Jaeger R-13. "Airplane Spotter" 8 / 11-1947, "EI" No. 376 reported:
"In Darmstadt, in November 1944, a group of German students, led by Dr. Lippisch, began work on the design of a jet aircraft designed for supersonic speeds. By the time of the occupation of Germany, a glider DM-1 was built. In our camp, no matter how strange it may seem, someone will try to destroy all data about the "Strela" and its successful tests in 1937, not stopping even before blaming the priority of our Motherland in the discovery of the most promising wing layout for orbital and supersonic aircraft back in 1934.
In 1957 only from foreign magazines it was possible to learn for the first time about "Sum" and "Strela". Our first memories of Arrow appeared in the book "Tested in the Sky" by M. L. Gallay, however, they distort the idea of an aircraft so much, turning its layout into a "pancake on slender little legs" that the development of aircraft does not serve. Compare the description of "Arrow" by Hallem ML. with the impression of the car of the test pilot A. A. Chernavsky. - "graceful swift triangle", as well as a similar one - in the book of test pilot Shelest I. I. - "… like an arrow, a sharp triangle."
As a result of successful tests of the Strela aircraft, I was offered to develop and create a combat aircraft with a propeller-driven group based on the Strela layout, bearing in mind the high speed data of the machine. However, even during the design of the Sigma aircraft, it was clear to me that such schemes with a VMG for subsonic speeds over conventional aircraft have no advantages in flight performance. Having communicated my considerations, I refused to create a combat aircraft with a propeller-driven group before the advent of jet engines necessary for flying at supersonic speeds.
What happened to the assignment issued by TsAGI in 1937? To the above, it must be added that the task given to the TsAGI Glavaviaprom for the study of a low aspect ratio wing and the creation of a glider by Kamenomostsky, the TsAGI designer, was not fulfilled. TsAGI limited itself to testing the Strela aircraft by VP Gorsky. In essence, these tests only clarified the tests of the Strela model carried out by A. V. Stolyarov. in the aerodynamic laboratory of Voronezh University.
About how "Strela" flew in the skies of Moscow and Voronezh, Rybko NS told in the newspaper "Young Communard" (Voronezh, November 3, 1976).
"For more than 25 years, scientists have calculated, modeled and created the shape of the wing, which was called" Gothic ", although this form was" born "in Soviet Russia, the place of its registration is Voronezh, and the year of birth is 1933. The twenty-nine-year-old Voronezh aircraft designer Moskalev Alexander.
For the sake of historical justice, this form must be named after its creator … I am sure that justice, in the end, will triumph and the priority of Aleksandr Sergeevich Moskalev, the priority of Voronezh, and finally, the priority of our country will be recognized. I would be glad if my testimony, the testimony of the Strel aircraft test pilot, would help in this matter.
At the Moscow Central Aerodrome in the hangar of OELID TsAGI in early September 1937, a rather strange Strela aircraft, designed by A. S. Moskalev, appeared. Single-seat, small-sized car, resembling a triangle in plan, with a 140-horsepower 4-cylinder Renault-Bengal engine. The pilot was placed in the fuselage, which was closed in front by a plastic fairing and the root base of the keel at the rear. The keel switched to the rudder. The elevators simultaneously served as ailerons, what are today called "Elevons".
The unusual shape of the aircraft caused a lot of criticism regarding its flight characteristics.
Young designer Moskalev A. S. and leading aerodynamicist of TsAGI V. P. Gorskiy. these remarks were not taken to heart and insisted on the fastest flights. Engineer Chesalov A. V., head of the OELID laboratory, also joined them. The matter remained only for flights. To begin with, we decided to see how the plane picks up speed on takeoffs and how easy it will be to take off the Strela.
Several pilots are trying to at least break away … and no success. The main feature of the Strela was that at the end of the takeoff run it was necessary to switch to high angles of attack, which was completely unusual for aircraft of that time. The pilots began to doubt the possibility of taking off and approaching. Then the factory pilot A. N. Gusarov, at the insistence of A. S. Moskalev, made several small flights. It was my turn to try the Strela plane. My first two runs were the same as the other pilots. During the third run, having already passed half of the airfield, I move the car to high angles of attack and - oh, a miracle! "Arrow" went into climb mode. I will try again, and I am firmly convinced that the flight is possible.
Observations from the outside and my explanations of the nature of the takeoff led to the fact that they allowed the flight. Fortunately for me, the start was at the airport from factory # 39. The takeoff run took place as usual. When civilian planes began to approach, I began to increase the angle of attack and the car quickly took off from the ground, almost immediately gaining a height of about 20-23 meters. Thus, I guessed the takeoff technique correctly. But, further "Arrow" ceased to gain height.
I assumed that the excess engine power was small, so I was afraid to make a U-turn and return to the airfield.
I am flying to the Tushino airfield. I was confused by one phenomenon in the behavior of the plane: it constantly swayed from wing to wing. The frequency and amplitude of the oscillation were small. Eventually, I stopped parrying them. I even tried to change the speed range within 40 km / h, but this did not give great results. There was not much time at my disposal and, without tempting fate, I landed at the airfield in Tushino. During landing, the engine was running at medium speed.
All rudders on landing worked normally, and lateral vibrations did not appear. The range of the first flight was about 20 kilometers.
Thus, it has been proven that the "Arrow" can fly.
My report that the aircraft lacks the ability to gain altitude has caused various opinions. A large number of people believed that the plane, shaped like that of the "Strela", was strongly influenced by the earth, that far from the ground, the car was not capable of gaining altitude. I looked at the airplane blowdown and calculations and saw that the plane would climb, but at high angles of attack. After much debate, I was allowed to take another flight.
The second flight, made in the fall of 1937, was quite successful. Having typed 1.5 thousand meters, I checked the Strela for stability and controllability. Everything was fine. The exception was lateral vibrations.
After discussing the flight results in OELID, it was decided to continue testing. I suggested Lake Pleshcheyevo. The town of Pereyaslavl-Zalessky is located on the shore of the lake, 150-170 kilometers from Moscow. Pleshcheyevo is an ellipse with axes equal to approximately 5 kilometers. The Arrow was transported there within 24 hours. The next day, the head of the flight department, Kozlov I. F. and I flew to PO-2. Lake Pleshcheyevo was an excellent airfield for Strela. Here I made 5 flights, confidently gained an altitude of 1.5 thousand meters. The exception was, of course, lateral vibrations; the plane had no peculiarities in flight. In a word, the car behaved the way an airplane should behave, having a similar power-to-weight ratio and load per square meter. m. Landings were carried out only with the engine running. The view from the plane on the ground seemed inadequate, but in the air it was quite satisfactory.
Flights on Lake Pleshcheyevo made it possible to obtain the flight characteristics of the Strela.
After the plane returned to OELID, it was decided to fly on wheels to find the cause of lateral vibrations. A. V. Chesalov proposed to hang the "Strela" on the hinges placed in the center of gravity of the aircraft and blow the machine in this state with the flow of the propeller, which is installed on the M-34 engine. During the experiment, I was sitting in the cockpit, trying to catch possible vibrations. Either the flow rate was low or the friction in the suspension was too high, but it was impossible to catch anything.
At the Central Aerodrome at the beginning of May 1938 I made my last flight. It did not bring anything new, except that 1.5 thousand meters were reached very quickly and, probably, it was possible to get a larger ceiling of the aircraft. According to Strela's estimates, without skis, only with wheels, the flight data was much better than with skis, but the flight performance was not recorded. To eliminate transverse vibrations A. S. Moskalev. proposed to install two additional keels along the edges of the plane. For this purpose, "Strela" was taken to Voronezh.
At the end of July 1938 A. V. Chesalov, V. P. Gorsky. and I arrived there. However, in Voronezh, the airfield was in such poor condition that it was impossible to carry out the Strela flights. At this point, my flights on this original machine, which, when modified, could turn into a promising combat aircraft, ended.
For the design of many modern fighters, the Arrow layout, which was made forty years ago, is borrowed.
Flight technical characteristics:
Modification - CAM-9;
Wingspan - 3, 55 m;
Length - 6, 15 m;
Wing area - 13, 00 m2
Empty aircraft weight - 470 kg;
Maximum takeoff weight - 630 kg;
Engine type - MV-4 piston engine;
Power - 140 hp;
Maximum speed - 310 km / h;
Practical ceiling - 1500 m
Crew - 1 person.
List of sources:
Moskalev A. S. Blue spiral
Wings of the Motherland. Ivanamin Sultanov. The competition has sunk into oblivion
Shavrov V. B. The history of aircraft designs in the USSR 1938-1950
Encyclopedia-reference. Aircraft of the country of the Soviets
