Experimental airplane Photon
OSKB-S MAI, story which began in 1965, by the beginning of the 1980s had a lot of experience. The first-born KB - an experimental aircraft "Quantum" - was successfully tested at the LII MAP. On this aircraft, five world records were set. The remotely piloted vehicle "D" in 1979 passed the first stage of testing, and the UAV "Komar" in 1982. Both devices were created in the interests of the military customer and could be used when reliable radio control systems appeared. The construction of the manned microplane “Elf” was coming to an end. All devices were designed and built in strict accordance with the requirements and standards that existed in aviation industry.
The work was conducted by students under the supervision of staff members of OSKB-S, as well as part-time teachers from the department of construction and design. Each year, students performed about 25 coursework and 15 graduation projects on real topics OSKB-S. Practically all the staff members of OSKB-S began their work in the team as students. In the pilot production, which worked on the topics of OSKB-S, 15 involved highly-skilled universal workers. OSKB-S is the only student design bureau of aviation universities of the USSR whose products in the Minaviaprom were recognized and allowed to be tested according to the rules that existed there.
The main task of the Mayevsky design bureau, on the one hand, was to improve the design training of students through their involvement in the creation of real engineering models, on the other hand, the use of qualified teachers and capable students to solve actual problems of the aviation industry as part of the educational process.
Since all the large design teams were headlong with work on maintaining their own production aircraft or prototypes (series-oriented), they had absolutely no time and desire to engage in experimental aircraft. These works seemed burdensome, and did not promise significant financial investments.
The Tenth Glavk Aviaproma in a similar situation in the face of OSKB-S found an energetic, talented and quite experienced team that is able to solve the tasks posed. And for the young “hoof-beating”, but already established design bureau, it was a great opportunity to prove its worth by reaching a new level.
The ideologist and leader of the team, who put a lot of effort into the organization of OSKBES, was Zidovetsky Kazimir Mikhailovich. He came to the design office back in the 1966 year, as a second-year student, at the initial stage of development of the Quant, and immediately attracted attention with his efficiency and erudition. Thanks to his authority, Kazimir Mikhailovich quickly headed one of the design teams, and later became the deputy head of the special design bureau for those. issues. Zhidovetsky developed the design of all the main units of the Kvant, the technology of their manufacture, then carried out the management of the construction and further flight tests of the aircraft. All aircraft, developed and built in the future, were created with the most active participation and under the direct supervision of Zhidovetsky K.M. When creating it, OSKBES was appointed the responsible head of the new design bureau and was approved by the order of the Ministry as the Chief Designer of MAP.
The main purpose of the experimental aircraft is to solve one or more scientific and practical problems in the field of flight dynamics and aerodynamics. From experimental experimental differs in that its subsequent mass production is not provided. As a rule, such an aircraft is created in one or two copies.
The creation of an experimental apparatus required much less cost than a prototype aircraft carrying cargo or weapons, target and navigation equipment, and a supply of fuel that provides the required radius of action. Also, when creating a prototype aircraft, it is necessary to work out the issue of serial manufacturability, maintainability, combat survivability, resource, ensuring the specified preparation time for the next flight, and so on. As practice shows, with the creation of a prototype aircraft, the flywheel of serial production prepares at the same time, since the customer quite often wants to have the car he needs tomorrow.
Some experimental problems are solved with the help of mass-produced aircraft converted for this. This gives a gain in terms and reduces the cost of research. However, even a specially built experimental aircraft provides considerable savings, if with the help of it it is possible to prevent the “insertion” of an erroneous concept into the experimental machines.
Often, the neglect of experimental verification becomes the cause of significantly delayed terms and tremendous funds that are thrown to the wind. A striking example is the first versions of the Su-24 bomber (ed. Т6-1) and the MiG-23 fighter (ed. 23-01), equipped with additional lifting engines for a shortened take-off / landing and a delta wing. In 1966, experimental aircraft T-58VD and MiG-21PD were built to test this concept based on serial fighter jets. Under pressure from the customer, prior to receiving the test results, the experienced Su-24 and MnG-23 were put into production. In 1967, both aircraft made the first flight. During the almost simultaneous testing of experimental and experimental machines, it turned out that this concept does not give the expected effect. According to Samoilovich OS, this is explained by the following reasons. First, jet jets of lifting engines at low speeds, reflected from concrete, are again sucked in by upper air intakes. Hot gases with a low oxygen content significantly reduced the thrust of lifting engines. Secondly, the overflow of air to the upper surface of the wing from under it, caused by the operation of lifting engines, changed the flow pattern and also reduced the carrying capacity of the wing. Thus, it was not possible to achieve a reduction in take-off and landing distances, and additional engines increased the mass and took up internal volumes, reducing the amount of fuel. As a result, both projects were radically converted into aircraft with variable sweep.
Another example. Before obtaining the results of testing the experimental MiG-21I aircraft (started in April 1968 of the year), specially designed to determine the characteristics of the lively wing for a passenger supersonic aircraft, laid an experienced Tu-144 (December 31 1968 of the year - the first flight). As a result, the Tu-144 aircraft radically changed the wing profile and corrected its shape in the plan.
The development and research of experimental aircraft in the United States has always received considerable attention. Suffice it to recall the first aircraft "X", with which at the end of 1940-x - the beginning of 1950-x. investigated the problems of supersonic flight. In 1950-1960-ies. Americans built more than 10 experimental X-series vehicles with which they studied various vertical take-off aircraft designs. Created in 1951, the experimental X-5 was the first aircraft in the world to have a variable sweep wing. Bert Rutan in the year 1979 commissioned by NASA to build an experimental aircraft AD-1 with an all-turning wing of an asymmetrically variable sweep. In 1984, a series of X-29 test flights with a forward swept wing was launched. In 1990, research on super-maneuverability continued on the experimental X-31. This list is far from complete.
In the USSR, this field of aviation science was developed much less. The “golden age” of domestic experimental aircraft fell on the 1950-1960. In 1957, for testing the vertical take-off, an experimental apparatus “Turbolet” was built, in 1963 - the Yak-36. On the basis of the serial Su-15 and MiG-21 in 1966, the already mentioned T-58ВД and MiG-21ПД were created. It was also said about the experimental aircraft MiG-21I "Analogue".
In this list, you can also add an experimental aircraft "Kvant", which was created at the Ministry of higher education, and not at the MAP. It was built in 1977 and in 1978-1984 was tested at LII MAP. Investigated the system of direct control of the lifting force, which was a maneuverable flaps, simultaneously working with the elevator while the aircraft control stick was deflected. True, the "Kvant" was forced into the category of experimental due to the fact that it blocked the road to the category of aerobatic flying aircraft. This was done by the influence and forces of Yakovlev LS, who at that time was a monopolist in the development of sports cars.
4 from 6 of the above experimental aircraft were created in large experimental design bureaus, the attitude of which to similar work was mentioned above. The only exceptions were “Turbolet” and “Kvant”, created in the design department of LII under the guidance of aerodynamics Matveyev V.N. and designer Rafaelyantsy A.N.
Organized in 1960-s. on the initiative of Myasishchev V.M. The tenth division of TsAGP, which was engaged in the study of promising schemes for aircraft, did not have any design and technological experience in the development of real aircraft.
Intensive progress in the field of aircraft in our country, which was observed before the collapse of the USSR, constantly raised questions, most of which could not be solved only by tube experiments or computational methods.
For OSKBES, the tasks were set directly by Simonov MP, deputy minister, and Shkadov L.M., head of the Tenth Main Board of the Ministry of Aviation Industry. The technical task was approved in LII and TsAGI.
The deputy minister of the aviation industry, Simonov Mikhail Petrovich, contributed a lot to the creation of OSKBES. He came to the ministry in the 1979 year, where, under him, the post of deputy minister for new equipment, pilot aircraft construction, which had been liquidated at one time, was resumed after deputy secretary general Yakovlev AS resigned. Simonov supervised the Tenth Main Office of the Ministry of Antimonopoly Policy, which was responsible for "science." Its scope included LII, TsAGI and all other research institutes of the aviation industry.
Simonov, who transferred to the ministry from the Sukhoi company, was admin. work and felt the need for design activity. Zhidovetsky K.M. said: "Mikhail Petrovich, apparently, was the only deputy minister in the entire history of the IAO, who had a drawing board in his office." Since Simonov's boiling energy was constantly looking for a way out, the order established in the MAP was rather quickly disturbed by some innovations.
So Samoylovich Oleg Sergeevich in his book recalls that at that time MP Simonov. put forward the idea that new aircraft should be developed at TsAGI, and not at design bureaus. At the same time, the OKB was only required to implement these projects. As an example, he cites the T-60 front-line bomber, the project of which was developed in TsAGI under the B-90 program (1960's bomber) under the leadership of Simonov and “lowered” to the Sukhov people in 1981.
Indeed, Mikhail Petrovich seriously “took into circulation” the Tenth (promising) department of TsAGI, and literally disappeared there. Under his leadership, in addition to the T-60, a project was developed for a single-engine experimental aircraft with a forward swept wing, similar to the American X-29. Since this plane was also supposed to be built by sukhovtsy, several young designers from the department of general types were attracted to work.
The next step, unconventional for the MAI, was the formation of the MAI in 1982 of OSKBES MAI with the direct support of Simonov, and after that - KN "Kvant" under the supervision of Yu.V. Kuznetsov, the head of SKB-S. These new design bureaus also had to be dealt with under the guidance of Simonov M.P. project research.
At the beginning of the 1980-s in Minaviaprom, work was launched on two promising programs: W-90 (1990's attack aircraft) and I-90 (1990-fighter aircraft). It was decided to involve OSKBES in the study of promising tech. solutions, the use of which would significantly increase the LTH of attack aircraft and fighters of the new generation.
For OSKBES, the first task was to determine the effectiveness of using SNNS (direct lift control system) on combat aircraft during maneuvering, aiming and targeting, including to simplify the landing technique of MiG-29K and Su-27K deck aircraft, which at that time just started to be developed. Under this program, it was supposed to conduct a series of test flights of "Quant".
Goryunov, NP, who was at that time the leading specialist of OSKBES in aerodynamics, recalled a funny incident that was related to that period. During the discussion of the details of the program with the leadership of LII, one of the OSKBES engineers drew the attention of Mironov A.D., the head of the institute, to the fact that landing on an aircraft carrier takes place without leveling and keeping up, which are usual for “normal” aviation. He was extremely surprised and at first did not even believe it. As a proof, the people of Maev offered to watch the film “The Sky Above His Head” (France), which at the time was in box office.
The picture was ordered, brought to LII. Her viewing for engineers and pilots was organized in the assembly hall of the Institute. In the film, the Super Etandaras from the Clemenceau aircraft carrier showed up in abundance, close-ups and beautifully, taking off from a steam catapult and landing on an aerofinisher. In addition, narrated about the love affairs of young pilots.
Shots from the film confirmed that the glide slope of the decline was directed strictly to the point of contact, and the slight curvature of the trajectory that occurs at the last moment was due to the influence of the proximity of the "earth".
Today, everyone knows that landing on an aircraft carrier has its own characteristics. Since it is performed "in ravens," the deck landing gear aircraft are significantly strengthened. And for Soviet test pilots, this science began with watching a French film with a light hand of MAI engineers.
In OSKBES together with the Sukhoi Design Bureau in 1983-1984. The possibility of developing a SNUPS aircraft laboratory based on the Su-15 serial aircraft was studied.
In connection with the forthcoming expansion of the range of tasks, as well as the possible increase in staff, the student design bureau in 1983 was transferred to a larger room of two cramped rooms.
The eternal problem of airplanes from the time of their appearance is an increase in take-off and landing speeds and, as a result, of the lengths of airfields, which inevitably follow attempts to increase the max. flight speed. At times, attempts are being made to somehow combat this trend. As is well known, on combat aircraft, powder accelerators are used to reduce the length of the takeoff run, and brake parachutes are used to reduce the length of the run. In this case, boosters are disposable devices, it can be said, consumables, but are forced to put up with this. In 1957, a setup was created for the aeronautical take-off of MIGT9С. The prototype aircraft, called the SM-30, was tested, but did not go into the series, since it was impossible to provide a non-aerodrome landing required by the military. The takeoff and landing capabilities of different aircraft must be of the same order.
One of the promising areas of increase in flight performance (LTH) of TsAGI aircraft was seen in the application of power systems to increase lift force (ESUPS). A well-known aerodynamic scientist, I. Ostoslavsky, also dealt with this effect. With the help of air bleeding from the RD compressor and its blowing through profiled slots, the effect of supercirculation on the wing is possible. This makes it possible to achieve values of the lift coefficient, which are substantially more than the traditional schemes of takeoff and landing mechanization provide. At the same time, the power system for increasing lift improved the take-off and landing characteristics of the aircraft.
In this area, besides the theoretical background of TsAGI in the USSR, there was little experience in the use of jet mechanization. On the MiG-21 fighters with 1964, starting with the modification of the MiG-21PFM, an ATP system (blowing the boundary layer) of flaps was installed. A similar system later began to equip Su-15 interceptors. On the An-72, which made its first flight in 1977, the Antonovans attempted to gain an increase in lift during take-off and landing by jetting jet sections of the upper surface of the wing with jets. In fact, avianauka could offer designers much more options for such mechanization.
The use of ESUPS while maintaining maneuvering and take-off and landing characteristics made it possible to reduce the area of the wing of the fighter, and this increased the maximum speed of its flight. The stormtroopers, this system allows basing on small areas near the front line.
In addition, the use of ESUPS was seen in deck aircraft. In our country at the beginning of 1980's, work was started on the creation of aircraft carriers of a new generation. The Soviet Navy was finally to receive full-fledged aircraft carriers that are armed with ground attack aircraft and horizontal takeoff fighters equipped with serious combat capabilities. Vertically taking off the Yaks, previously used on aircraft carriers, according to apt expression, "could only carry their own stars on their wings."
In parallel with the construction of aircraft carriers deck aircraft were created. In the Mikoyan and Sukhoi Design Bureau in 1983, work was carried out on the draft designs of the deck MiG-29K and Su-27K. Their high level of armament, which was equal to and even slightly exceeded one, made it possible to launch from the deck without using a steam catapult, as was the case on most foreign aircraft carriers. However, the refusal to equip ships with a catapult required some other solution for taking off strike aircraft that did not have such a high thrust-weight ratio as fighters. The most promising option to ensure unattended takeoff at a short distance was the energy mechanization of the wing. The main difficulty was that the ESUPS could not be investigated on reduced models in wind tunnels. In this case, the main element of energy mechanization under study - a slit 1-2 of a millimeter thickness, through which air is blown onto the wing, would decrease to a value of several microns. With such dimensions, firstly, it is extremely difficult to maintain the accuracy of its profiling. Secondly, and this is the main thing, there was a difficulty in observing the aerodynamic similarity, making such an experiment meaningless. To study this concept in real conditions and to work out constructive solutions for its implementation, it seemed expedient to create an experimental aircraft.
In the late 1970s. with the Americans, Rockwell International commissioned by the Navy fleet The United States built an experimental XFV-12A carrier-based fighter-attack fighter with short and vertical take-off / landing (depending on weight). Its wing and front horizontal plumage (PGO) were equipped with ESUPS. To reduce the complexity and, consequently, the production time of this aircraft, the Americans used ready-made units of serial aircraft in its design: the bow (front landing gear and cockpit) from the A-4 Skyhawk attack aircraft and the caisson part and wing air intakes from the F- fighter 4 Phantom.
Zhidovetsky was asked to evaluate the strength of OSKBES to determine the direction of work: in the interests of the topic W-90 or I-90. Within a short time, he developed and proposed experimental aircraft configurations for investigating the lift system in the interests of both directions.
When developing a new generation of Soviet fighter aircraft, it was decided to dispense with competition between Mikoyan and Sukhoi fighters, as ten years earlier during the creation of the MiG-29 and Su-27. Here, probably, the role played by Deputy Minister Simonov, who had recently left the Sukhoi Design Bureau in connection with difficult relations with General Designer Ivanov E.A. and his deputy Samoylovich OS Anyway, the task for the I-90, more prestigious for both companies, was issued by the Mikoyan Design Bureau, and the development of the W-90 was assigned to the Sukhov people. Simonov MP who returned to 1983 to Sukhoi’s firm as General Designer, had to proactively take up the topic of the promising C-32.
On the topic X-90, the experimental aircraft was carried out according to the aerodynamic “duck” scheme with two jet engines RU19А-300, equipped with flat nozzles with thrust vector control. These experimental nozzles for engines were developed in the design department of LII. On an airplane with such a configuration, the elements of super-maneuverability were to be worked out according to a program that was similar to that under which the United States was going to create an experimental X-31. At that moment, the Americans were just starting to develop it. Domestic aircraft was distinguished by the fact that the wing was equipped with a system ESUPS, which worked from the engine compressors. To reduce costs and time for the construction of the aircraft, it was proposed to use the cabin, bow, wing box, keel and landing gear of the Czechoslovak-made jet training aircraft L-39.
The design of the aircraft allowed the replacement of the wing: it could be either reverse or forward sweep. By the way, in the United States for research maneuverable capabilities of the wing having a reverse sweep created the X-29 aircraft.
Engineer Vyacheslav Khvan participated in the development of the scheme, who shortly before that graduated from MAI and came to OSKBES.
After the scheme was approved by Simonov and Shkadovy they made a demonstration model. Since the plane was going to be built in the interests of the I-90 program, it was necessary to coordinate its scheme with the leading firm on this topic, namely the Mikoyan Design Bureau. Yuri Alekseevich Ryzhov, the MAI Vice-Rector for Science, phoned Rostislav Anollosovich Belyakov, General Designer, and quite unexpectedly received an invitation immediately to come to him along with Zhidovetsky, the Mykoyan Design Bureau is located not far, across Leningradka opposite the institute.
Since it was necessary to carry a model aircraft with him, Yuri Alekseevich suggested using his own Volga. Ryzhov's “crusts” allowed him to drive to the design territory of the design bureau, but Kazimir Mikhailovich did not have time to get an ID of the Chief Designer of the IAO, so there could be difficulties with his journey to the OKB. The usual pass had to be ordered the day before, but who knew that the meeting with Belyakov would take place immediately.
Exit found sitting behind the wheel Ryzhov. He gave his ID to Casimir and said: "Tell me about me that I am a chauffeur." Passing drove smoothly.
The first reaction of Belyakov, after he saw the model brought in, was a surprise, after which he tried to find out how information about the development of his advanced 1.42 fighter jet was leaked to the MAI. He calmed down only after he noticed that the OSKBES car has one keel, while the 1.42 had two.
When almost all of those. the issues related to the “improvement” of the scheme with its implementation were resolved, suddenly a non-technical problem arose. It was 1982 year, the “mode” was strictly observed, and the level of secrecy of the scheme of this aircraft, taking into account the “neck” of the program, in the interests of which it was created, was recognized as high. For security reasons, student design bureaus could not be allowed to work on this topic. There were two ways out of this situation.
Either the design bureau changed its status, becoming experimental without a student component with all the ensuing consequences, or it continues to engage in an experimental aircraft on W-90, which was developed in parallel with the first theme by Zhidovetsky and the scheme of which didn’t carry such secrecy.
Zhidovetsky and Ryzhov, after weighing all the pros and cons, chose the second path. The topic was given the name "Photon".
In shaping the look of the aircraft, more than twenty different layouts worked. One of the first versions of the experimental aircraft "Photon", arranged at the suggestion of TsAGI Zhidovetskim, had a straight wing, a traditional aerodynamic layout and located in the nose of the TMD-10B TRD. The work of ESUPS was provided by two auxiliary power units (VSU) of the AI-9, located on the wing in the gondolas. The main landing gear was cleaned in the same gondola. Nose - was removed in the fuselage. The T-shaped tail unit allowed the stabilizer to be removed from the zone of significant oblique flow behind the wing, which is equipped with ESUPS. This scheme was rejected by LII, since blowing a wing from a screw from a screw would spoil the flow pattern, which is undesirable for an experiment.
After that, they developed a variant of the "Photon" having an AI-25 turbojet engine mounted above the central part of the fuselage, and a two-fin exploded plumage. This arrangement was also discussed with LII and TsAGI.
As a result of all these preliminary works, Zhidovetsky was visited by the idea to combine both versions of the power plant - turret fuse and turboprop engines, in case of refusal of additional AI-9. For the needs of ESUPS, air could be drawn from the secondary circuit of the AI-25T turbofan engine. In addition, Zhidovetsky in this layout laid the decisions that would allow in case of successful completion of the experimental program to use the machine as a prototype of a serial light attack aircraft.
"Photon", according to Zhidovetsky KM, was to occupy its own niche among existing combat aircraft and be a kind of "scalpel" in the hands of the military, which will be particularly effective in local conflicts. It was assumed that these aircraft will be used to respond to the request of the ground forces, based around the front line on field airfields of small size. To do this, the aircraft must have excellent take-off and landing characteristics. The energetic mechanization of the wing of the Foton aircraft was to provide properties unprecedented for this class of machines.
To clarify the urgency of this concept of combat aircraft can be explained by the following example. During the Balkan 1999 conflict, NATO fighter-bombers who bombed Serb military facilities in Kosovo took off from Aviano's air base (Italy), which was several hundred kilometers away. At the same time, the error of the navigation calculations was so large that several times air strikes were inflicted on columns of Albanian refugees in Macedonia, for the sake of protection of which, in fact, NATO combat operations were conducted. Attack pilot who is based in tens, not hundreds of kilometers. from the line of combat contact, it is unlikely to confuse the country to be bombed.
By the end of the 1960's. military experts of the leading countries of the world came to the conclusion that the accuracy of destruction of ground targets from supersonic fighter-bombers with missile-bomb armament is not high enough. The high speed of these aircraft gives the pilot very little time to aim, and poor maneuverability does not allow to correct the inaccuracy of aiming, especially when striking low-profile targets. Then in the United States appeared subsonic maneuverable attack aircraft A-10 company "Fairchild" (1972 year), and in the Soviet Union - Su-25 (1975 year).
By the way, the concept of “field” basing near the front line was laid by the designers at the initial stage of creating the Su-25. It was assumed that the attack aircraft will be equipped with two dual-circuit, relatively small, AI-25 engines (installed on Yak-40 passenger planes), it will have take-off weight 8 thousand kg, combat load - 2 thousand kg, operating speed range - from 500 to 800 km / h and range - 750 km. The main thing - the aircraft must be operational means of supporting ground forces. The command of the Ground Forces, understanding this, fully supported the creation of the aircraft, while the Air Force for a long time towards him showed complete indifference.
However, jealousy on the part of the Air Force Command, the reluctance, together with the aircraft, to give the ground vehicles airfields with infrastructure and regular personnel units led the customer to take up the project seriously. As a result of repeated demands for increased speed and combat load, the Su-25 began to take on the 4th board. kg of ammunition, and its maximum speed increased to 950 km / h. However, having transformed into a multi-purpose aircraft from an “battlefield” aircraft, Su-25, with a twice-increased take-off mass (17,6 thous. Kg), lost its ability to base on minimally prepared small areas near the front line, instantly “working off” the targets on ground requests. To shorten the response time during the war in Afghanistan, it was necessary to organize the airborne duty of attack aircraft.
Light attack aircraft "Photon" was really to become an aircraft directly supporting the ground forces.
The main feature of the "Photon" scheme was a spaced-off redundant power plant, which consisted of a TVD-20 turboprop engine located in the forward fuselage and an AI-25TL turbojet located behind the cockpit. Such placement of engines reduced the likelihood of their simultaneous defeat from enemy fire, and also provided additional. protection for the pilot who sat in the titanium welded “bath”, as in the Su-25. Inside the design office, the project immediately received the second name - “Push-pull”.
According to Kazimir Mikhailovich, for an attack aircraft that constantly works in conditions of powerful fire resistance, a low profile scheme is preferable by many criteria. The structural elements of the low-lying horizontal tail and wing protect the engine and pilot from fire from the most probable directions from the ground.
It is also known that the plane of the “nizkoplan” scheme provides the crew with much greater safety during an emergency landing with an unreleased landing gear, the probability of which for an attack aircraft is very high. This can be explained by the fact that the wing center section is a very solid construction, which takes on the load, both in flight and during a forced landing, thereby protecting the crew. For an aircraft with a high-profile circuit for this case, the bottom of the fuselage is additionally enhanced. The wheels of the main chassis of the "Photon", half protruding from the niches, also increased the chances of a safe landing in the event of a malfunction of their release system.
To date, the most common and effective means against low-flying aircraft are MANPADS (man-portable air defense systems) such as Igla, Strela-2 (Russia) and Stinger (USA). Practically all of them are equipped with an optical infra-red hsn, which reacts to the hot nozzle of a jet engine, and are mainly launched into the rear hemisphere of the target.
The layout scheme that Zhidovetsky chose for “Photon” also took this into account. The redrawn inverted scheme with the location of the AI-25 engine nozzle above the tail boom and the low-lying horizontal tail with separated keels made it difficult to capture the target with thermal seeker from the most probable firing angles. The vertical two-tail unit also increased the combat survivability of the aircraft, meeting the requirement for redundancy of the main structural elements.
For the "Photon" chose a chassis scheme with a tail bearing, since it provided a higher throughput. True, an aircraft that has such a landing gear scheme is more difficult to control during takeoff and landing. Firstly, the pilot must take special care to maintain the direction of run and run, as the aircraft tends to spontaneous reversals. Secondly, since the start of the run begins with the parking value of the angle of attack of the wing, the pilot must first give the control stick away from himself, tearing off the tail and reducing the angle of attack (and therefore resistance), and only then, having gained the necessary speed, pulling the handle towards himself take off the ground.
Zhidovetsky KM, to overcome these shortcomings of the chassis with a tail bearing, a circuit with a loaded tail pillar was used. This meant that the tail wheel accounted for the largest part of the aircraft’s mass than is customary. Thus, the necessary directional stability was ensured during the takeoff and run of the aircraft. And the significant starting thrust-carrying capacity of the Photon and the possibility of separation by turning on the ESUPS at the required moment, when the necessary takeoff speed was reached, allowed us to take off from three “points”. These factors made it possible to easily master the new aircraft to pilots of medium qualification, who had not even flown on planes with a tail wheel before.
Despite the location in the nose of the TVD-20 engine, the layout provided excellent forward-down view of the pilot, which was certainly necessary for an aircraft of this purpose. All the windows of the cockpit canopy were made of bulletproof glass. The cockpit was equipped with an ejection seat.
Both engines, AI-25TL (kg 1700 thrust) and TVD-20 (hp 1375 power), operated at maximum speed during takeoff. The air that was taken from the second loop of the AI-25ТL engine ensured the work of jet wing mechanization during take-off and landing.
Also, both engines were used for quick access to the goal and care after completing the task. The loitering mode in the target area or cruising flight was provided by a more economical TVD-20, while the AI-25TL was switched to idle mode, for less fuel consumption.
The need for an attack aircraft of such an economical regime, which provides a longer flight time, was identified at the last stage of the combat operations of the Soviet troops in Afghanistan. In the winter of 1988-1989, the columns of the Fortieth Army retreated along mountain roads to the Union from Afghanistan. Helicopters and attack aircraft Su-25 covered the withdrawal of troops from the air in case they were attacked by ambush columns on the march. The remoteness of the airfields located on Soviet territory, as well as the high fuel consumption of the RD, did not allow the aircraft to remain for a long time over the concealed troops. That is why at the end of the 1980-x and the beginning of the 1990-s, Sukhoi’s company, within the framework of the W-90 program, also worked out a draft attack aircraft, which was to be equipped with a pair of fuel-efficient turbojets.
Since the take-off mass of the "Photon" was 3 tons, and it had a rather unusual appearance, one of the OSKBES wits called it "Triton."
The armament of a light attack aircraft was to consist of free-fall aerial bombs, uncontrolled air raids for firing at ground targets, and guns in underwing suspended containers. In the case of the use of the aircraft as a fighter helicopters and for self-defense, he could carry self-guided missiles "air-to-air" melee equipped with infrared seeker. Also, the aircraft could be used to destroy remotely piloted aircraft.
The design of the aircraft and the carefully executed model were demonstrated at Piyrogovka at the headquarters of the air force, as well as at other instances of the military department, but everywhere ran into the same reaction: “Everything that carries less 5 tons of bombs is of no interest to us!”. The military does not need a scalpel. Much more convenient to use the "club".
So, to enlist for the implementation of the project "Photon" support of the military did not work. The customer - the Tenth Main Command Board - believed that the creation of an experimental aircraft would be very expensive. It also seemed to TsAGI that for solving the set task - research of ESUPS - this scheme is unnecessarily complicated. LII categorically opposed the use of a screw power plant.
Also, the fate of the TVD-20 remained unclear. It was developed under the An-3, but with the termination of this program, the question of fine-tuning and serial production of the engine hung in the air. Zhidovetsky proposed to develop a simplified version of the aircraft. The technical assignment for the aircraft was developed at LII and TsAGI, and 10 was approved on July 1984 by the Deputy Minister.
During 1984, a draft design of an aircraft of the same name was developed, but a completely different scheme. We chose the RUNNXXА-19 jet engine (kg 300 thrust) as the main engine. Since the modifications required for air extraction could not be coordinated with the engine design bureau, the X-NUMX of AI-900 gas turbine units had to be installed on the plane for jet mechanization. On the one hand, this seriously complicated the design, but on the other hand, an autonomous air source made it possible to change the ESPS parameters regardless of the main engine mode. Four AI-4 placed on the sides of the fuselage under the fairing in pairs.
Goryunov Nikolai Petrovich recalls that the developers were very worried about the single figure in those. characteristics AI-9 - the maximum time of continuous operation of the unit. According to his passport, this figure was equal to 45 seconds, while on the Photon he needed to work continuously for much longer. To resolve this issue and get detailed documentation, a group of USC-BES workers was seconded to the Lotarev Design Bureau in Zaporizhia.
Engine KBs could not answer what caused this restriction, and whether its excess is possible. When Muscovites were already desperate because of a deadlock, one of the oldest employees of the design bureau was found who remembered that in technical terms the figure was 45 seconds. appeared only because it was necessary for those. task Yakovlev, for which was created AI-9. In fact, the unit could continuously work up to the full use of the resource.
On the plane for the purity of the experiment was used a straight wing without narrowing. To reduce the influence of interference with the fuselage on its characteristics, the wing was made mid-range. He was "untied" from the chassis, setting it on the fuselage, for the same reasons. The wing was developed in TsAGI 16 percentage profile of the P-20. The wing in the power relation represented a caisson divided on scope by detachable consoles and the center section. Replaceable rear and front modules of energy mechanization were installed on the console.
So that the powerful bevel of flow behind the wing, caused by the effect of supercirculation, did not reduce the efficiency of the horizontal tail, it was carried to the top of the keel of a large area. To ensure longitudinal balancing of the aircraft on take-off and landing modes with a working ESUPS, the horizontal tail was given a relatively large area, which was almost 30 to percent of the wing area and 12 asymmetric inverted profile.
In order to simplify the design and taking into account the fact that the aircraft will mainly work out takeoff and landing modes, it was decided to make the landing gear non-retractable.
The design of the aircraft was high-tech. The fuselage contours implied a minimum of double curvature skins. They were made of fiberglass. All loads were perceived by the upper part of the fuselage, a kind of “ridge”, which was divided into layouts into the cabin, the middle part, which serves to accommodate the fuel tank, and the tail part. The wing center section was attached to the middle part of the fuselage; under the tail section, the RU19А-300 main engine (developed for the Yak-30 training aircraft, used as an auxiliary power unit on the An-26 and An-24РВ). The main landing gear were attached to the wing center section, to which also mounted on the 2 unit AI-9 (used as an auxiliary power unit on the Yak-40) on each side. The entire lower part of the fuselage consisted of opening hoods and removable skins, which provided excellent access for servicing a bulky and complex power plant. The air intake of the main engine was carried forward by the nose strut of the chassis to prevent foreign objects from getting into the UPU, tossed by the wheel. On a horizontal platform, test equipment was placed in the nasal fiberglass fairing, the approach to which was ensured by sliding the entire fairing along the sensor bar of the angle of attack, slip and speed forward. The front compartments of the side fairings were also used for testing equipment. The flat bottom surface of the nose cone at high angles of attack was supposed to compress and align the air flow that entered the engine air intake.
The central control post was taken from the MiG-29 fighter. The aircraft installed an ejector seat K-36ВМ class «0-0», used on aircraft with GDP. In the tail of the fuselage was placed container antispin parachute.
Estimated take-off weight of the "Photon" - 2150 kg. The maximum speed should have been 740 km / h and the rate of climb of 23,5 m / s. Without ESUPS being turned on, the minimum speed was 215 km / h. In the case of using ESPS, it should have been almost halved - 125 km / h.
At the All-Union 1984 / 1985 competition of the school year, the Photon project for the best scientific work among university students took second place. Bobrov A., Dunaevsky A., Svinin S., Merenkov S., Serebryakov A., Alexandrov I., Chernova N., brothers Sabatovsky S. and Sabatovsky A. (24 MAI student) received cash prizes and medals of the competition as authors of scientific research work "Project of the experimental aircraft" Foton ". Also noted the leaders of the work Zhidovetsky K.M., Kozina Yu.V., Goryunova N.P. and Khvan V.T.
As already noted, it was impossible to work in a small wind tunnel on smaller models of ESUPS due to the difficulty of observing the aerodynamic similarity, and it was too risky to lift an experimental machine with such an unexplored circuit right into the air. In this regard, the first copy of the "Photon", the construction of which began in 1985, was intended for purging in the natural wind tunnel TsAGIT-101.
To study the pattern of flow around the aircraft during operation of the AUPS, there were more than 1200 points for measuring static pressure on the wing surface, fuselage in the wing zone and tail unit. The pressures from these points were removed from the aircraft through pneumatic switches to the racks of aerodynamic weights and then to measuring devices that were outside the working area of the pipe. The leading engineer of OSK-BES, Konenkov Yuri Stepanovich, for the Foton pipe version, developed and manufactured a remote control system for steering surfaces, bypass valves of the pie system and flaps. Each controlled surface was equipped with a position sensor.
Also, the first copy served as a model for working out the layout of the cabin, the placement of equipment and components of the control system. All the main parts were made in three sets: for the pipe, static and flight copies of the aircraft. True, a copy for static strength tests and a flight copy were to be made at the end of a complex purging program. The difficulty was that the design of the aircraft involved the use of more than a dozen variants of jet wing mechanization combinations. During the assembly of the "Photon", the workshop of experimental aircraft of the EOZ MAI was under the direction of Mikhail Tetyushev. Lead designer for the assembly of the aircraft - Demin Vadim.
Since the production capabilities of the MAI Experimental Experimental Plant were very limited, they organized extensive cooperation with the aircraft plants of Moscow. This involved Kuznetsov Gennady Viktorovich. At the Sukhoi pilot plant, glass was made for the folding part of the cockpit canopy, as well as most of the curved parts, such as wing loops, rudders, tail pieces and fuselage skin. Electroplating of all large platings and part of the bent parts was carried out at the Ilyushin pilot plant. Nasal fiberglass fairing glue on the Moscow Helicopter Plant named Mile in Panki. Screw locks for numerous opening hoods were ordered at the Gorky aircraft factory, where they went to the MiG-31 and MiG-25.
For the "trumpet" instance of the "Photon" chassis was not required. The aircraft in a full-scale pipe was supposed to be placed on racks of aerodynamic weights; at the same time, through them, air was supplied under pressure, which ensured the work of energetic wing mechanization.
The development of a regular chassis was to be carried out at the second stage of work - during the creation of the Foton flight copy.
"Pipe" instance to move on the ground was equipped with a technological chassis. To do this, use the front and main rack Yak-18T. Since the main pillars of the Photon, unlike the Yak, were mounted on the fuselage, and not on the wing consoles, they had a small “camber”. In this regard, the wheels of the Jacob pillars were set at an angle to the vertical. For all those who saw the plane for the first time, this raised puzzled questions. Nevertheless, this “non-native” chassis made it possible for the “Photon” on the trailer behind the truck to get under its own power to Zhukovsky from MAI, which is approximately 80 km.
Together with the aircraft produced several wing replacement modules ESUPS.
The construction of a “pipe” instance of the “Photon” was completed in June 1986 of the year at the MAI Experimental Experimental Plant, after which the aircraft was sent to TsAGI. As always, they drove at night along the ring road around Moscow at low speed, accompanied by traffic police. I remember the moment when, at about five in the morning, we reached the bridge over the Pehorka, found ourselves in a cloud of fog that had accumulated in the valley of the river. Visibility was less than a couple of meters, and therefore low speed was reduced to pedestrian.
So, TsAGI began to prepare the plane for testing in the T-101 tube. A team of OSKBES engineers went to TsAGI on a long trip together with "Photon". Demin Vadim was the leader in aircraft design, Kozin Yury Vladimirovich and Serebryakov Alexander were responsible for the operation of the pneumatic system, Filippov Volodya was in charge of the measurement system. Vyacheslav Khvan was the scientific adviser from the MAI. Aleksey Nikolayevich Pakin was appointed the leading expert from TsAGI, and Albert Vasilyevich Petrov, the leading aerodynamic power engineering specialist in the USSR, provided general scientific guidance. For the entire time of the test, “nurse” for the Mayev brigade was Filin Alexander Sergeevich, the leading engineer from preparatory T-101. The owl taught all the subtleties of preparing the work in the pipe and the work itself.
The first attempt to test the pressure of the pneumatic system of the aircraft discouraged designers. In preparing for it, everything was done carefully, with the observance of all precautionary measures. A high pressure could “inflate” the structure, and a safety valve otterirovany to the desired pressure was absent. He also had to develop. It was decided to place Filippova Volodya with an ax near the hose, which supplied the plane with air, in order to cut the hose at danger. How surprised the whole crew was when the gauge needle did not even flinch after the air supply. Despite the fact that the pneumatic system of the aircraft was collected on the sealant, it did not hold pressure. Complete elimination of leaks took more than one month.
Before installing the plane into the pipe, it was necessary to work out the ESUPS in "static". After eliminating the pressure loss the plane in the liner “sang”. It was a high frequency vibrated plating that formed a gap. In addition, under pressure, the thickness of the gap between the fasteners doubled. Two millimeter dural lining were replaced with three millimeter stainless steel.
The selection of the profiling of the gap, as well as the relative positions of the flap and the gap, required special care. In order to visualize the spatial spectrum of the flow around and confirm the sticking of the jet to the flap in all ranges of its deflection angles, special clamps with silk fibers were made. A lot of time was spent on providing the same spectrum of mechanization flow along the entire span of the wing.
With the help of miniature sensors, the total pressure in the slit and supply lines was measured. Since the end of the 1940-s, the TsAGI gas dynamic test experience has been almost completely forgotten. I had to look for old specialists who still remember the methods of conducting such experiments and processing the results. Such a specialist was Azat Sadgeevich Chutaev, who provided substantial assistance in conducting the Foton tests.
It turned out that the plane is only half the battle. It turned out that the instrumentation equipment of TsAGI does not provide an experiment. For example, she could not simultaneously measure pressure at a thousand (and even more) points on the surface of an aircraft. Work had to start with the creation of such equipment.
In order to visualize the velocity field behind the wing, a lattice with silks was made, which could be installed at various distances behind the wing, showing the influence of the flow slant on the tail and the flow pattern.
The engineers of the MAI brigade during their work at TsAGI in general received more than 20 certificates for inventions in the field of aerodynamic engineering.
During aircraft purging, a complete set of aerodynamic characteristics for one of the configurations (landing or cruising) is obtained in one run of the pipe. The aircraft is driven through all the slip angles at each angle of attack, with a step of a few degrees. The characteristics of the "Photon" for each combination of angles of attack and slip also depended on the air flow in the power system to increase the lifting force. In this regard, the number of fixed test points increased by an order of magnitude. Also, the program provided for the study of several variants of replaceable modules for the mechanization of the trailing and leading edges of the wing.
Blowing was carried out on the front edge of the wing, on aileron, on the usual rotary flap (up to the deflection angle of 180 degrees), on the round rear edge of the wing. Also tested round rear edges of different diameters. The latter was of particular interest, since the wing design was simplified and facilitated (due to the absence of moving elements - ailerons and flaps), the combat survivability and reliability increased, it became possible to use the entire wingspan to increase the bearing capacity. In this case, the roll control was carried out by asymmetric blowing on the wing, to which a large blowing program was dedicated. True, they feared that in cruise flight the round rear edge of the wing would cause an increase in resistance. However, in the process of testing, we found a way to solve this problem without constructive complications, practically “for free”.
The effect on the flow around the wing of the flow turbulators (spoilers) and their optimal location along the wing chord was also investigated. In addition, a study was conducted on the effect of different wing tips and partitions between aileron and flap sections.
In addition to the original configuration, the aircraft was flushed with horizontal tail, transferred to the fuselage from the keel. The characteristics of the air intake and its canal were also investigated, counting on the construction of a flight copy of the Foton aircraft. Since TsAGI was interested in the work of ESUPS in the jet of the screw, they planned to blow the "Photon" with a screw installation placed in the pipe in front of it.
With the "Photon" in terms of purges in the T-101, not one of the aircraft previously built in the USSR could match. Tests conducted in two shifts. No one counted the number of "pipe" clocks, however, this example is typical: when it was required to carry out tests in the pipe of another plane, the Photon was briefly filmed, the guest was quickly blown and the owner was installed on the scales again. The main competitor of the "Photon" for "pipe" time at that time was the MiG-29.
Before each installation in the pipe, long hours were spent on ground tests and careful debugging of the next configuration of power systems to increase lift in the “statics”.
As a result of the tests, they obtained a huge in volume and material of a unique ESPS value. After all, even today, it is impossible to obtain similar results using purely computational methods. This is the only such deep study of this trend in the USSR. The participants of this work have accumulated not only theoretical, but also design and technological experience (which is very important!) In the field of energy systems for increasing lift.
In short, you can give two figures that give a qualitative picture of the results achieved. The efficiency of power systems for increasing lift is characterized by a recovery coefficient on the total pressure profile. Its value shows the cost of energy that must be brought to the stream flowing around the wing in order to maintain a continuous flow. For a typical configuration, the usual rotary slit flap, deflected at an angle of 60 degrees, this factor for "Photon" is equal to 0,05. For comparison, on the An-74, the Antonovites reached twice the value, and therefore less effective. Judging by the appearance at the MAKS-2001 An-74ТК-300 air show with engines that are traditionally located under the wing on the pylons, the gain from blowing part of the wing was much less than the loss in ease of engine maintenance.
The maximum lift coefficient, which was obtained during the experiments on the "Photon", was 3,6. It is necessary to clarify that this is not the dry-air profile obtained on the wing compartments of infinite elongation in wind tunnels. This is the coefficient of the actual layout of the aircraft with the fuselage, which "eats" a significant part of the wing span. For comparison, the Fowler Three-slot Flap can be equal to 3,5, however, the complexity of the actual design of such a flap is much greater than ESUPS.
According to the results of the tests, "Photon" developed two special aerodynamic profiles of the wing, which allow to obtain the best performance with power systems to increase lift. She has also been tested at TsAGI.
Funding for the topic from the MAP began to expire already in 1988, and in 1989 it stopped completely. It became clear that the construction of the flight copy of the aircraft "Photon" will not take place. Despite this, the military, who were interested in the results of this topic, continued to find funds for the continuation of the testing of the Foton pipe sample until 1993. A change in the country's political course, as well as a reduction in research expenditures (in various sectors of science, on average twenty or more times), did not completely allow the implementation of the Photon program.
Undoubtedly, the work on "Photon" was a serious test of the scientific design level for the OSKBES MAI team, as well as an important milestone for its history. And if it were not for the collapse of the USSR and its aviation industry, this interesting project would undoubtedly bring it to the stage of a flight experiment, and other equally interesting and serious developments would follow.
The introduction of ESUPS in aviation can be compared with the revolution that was caused by the appearance of landing pads and flaps in 1930 on airplanes, and in 1960 - the variable sweep of the wing. The advantages of ESUPS compared to variable sweep and take-off and landing mechanization are its speed, relative structural simplicity, as well as higher achievable values of the lift coefficient. Also ESUPS can be used in different combinations with them.
The results of the research on "Photon" were laid in another project of Zhidovetsky - the jet administrative aircraft "Aviatika-950", which was developed in 1994-1995 in the framework of the Aviatika concern.
Aircraft performance characteristics:
Modification - Photon;
Wingspan - 7,32 m;
Length - 8,27 m;
Wing area - 7,32 m2;
Empty weight - 700 kg;
Maximum take-off weight - 2150 kg;
Engine type - turbojet engine RU-19-300;
Thrust - 900 kgf;
Maximum speed - 740 km / h;
Flight duration - 1 h .;
Practical ceiling - 10700 m;
Maximum operating overload - 6,85;
Crew - 1 man.
The work was conducted by students under the supervision of staff members of OSKB-S, as well as part-time teachers from the department of construction and design. Each year, students performed about 25 coursework and 15 graduation projects on real topics OSKB-S. Practically all the staff members of OSKB-S began their work in the team as students. In the pilot production, which worked on the topics of OSKB-S, 15 involved highly-skilled universal workers. OSKB-S is the only student design bureau of aviation universities of the USSR whose products in the Minaviaprom were recognized and allowed to be tested according to the rules that existed there.
The main task of the Mayevsky design bureau, on the one hand, was to improve the design training of students through their involvement in the creation of real engineering models, on the other hand, the use of qualified teachers and capable students to solve actual problems of the aviation industry as part of the educational process.
Since all the large design teams were headlong with work on maintaining their own production aircraft or prototypes (series-oriented), they had absolutely no time and desire to engage in experimental aircraft. These works seemed burdensome, and did not promise significant financial investments.
The Tenth Glavk Aviaproma in a similar situation in the face of OSKB-S found an energetic, talented and quite experienced team that is able to solve the tasks posed. And for the young “hoof-beating”, but already established design bureau, it was a great opportunity to prove its worth by reaching a new level.
The ideologist and leader of the team, who put a lot of effort into the organization of OSKBES, was Zidovetsky Kazimir Mikhailovich. He came to the design office back in the 1966 year, as a second-year student, at the initial stage of development of the Quant, and immediately attracted attention with his efficiency and erudition. Thanks to his authority, Kazimir Mikhailovich quickly headed one of the design teams, and later became the deputy head of the special design bureau for those. issues. Zhidovetsky developed the design of all the main units of the Kvant, the technology of their manufacture, then carried out the management of the construction and further flight tests of the aircraft. All aircraft, developed and built in the future, were created with the most active participation and under the direct supervision of Zhidovetsky K.M. When creating it, OSKBES was appointed the responsible head of the new design bureau and was approved by the order of the Ministry as the Chief Designer of MAP.
The main purpose of the experimental aircraft is to solve one or more scientific and practical problems in the field of flight dynamics and aerodynamics. From experimental experimental differs in that its subsequent mass production is not provided. As a rule, such an aircraft is created in one or two copies.
The creation of an experimental apparatus required much less cost than a prototype aircraft carrying cargo or weapons, target and navigation equipment, and a supply of fuel that provides the required radius of action. Also, when creating a prototype aircraft, it is necessary to work out the issue of serial manufacturability, maintainability, combat survivability, resource, ensuring the specified preparation time for the next flight, and so on. As practice shows, with the creation of a prototype aircraft, the flywheel of serial production prepares at the same time, since the customer quite often wants to have the car he needs tomorrow.
Some experimental problems are solved with the help of mass-produced aircraft converted for this. This gives a gain in terms and reduces the cost of research. However, even a specially built experimental aircraft provides considerable savings, if with the help of it it is possible to prevent the “insertion” of an erroneous concept into the experimental machines.
Often, the neglect of experimental verification becomes the cause of significantly delayed terms and tremendous funds that are thrown to the wind. A striking example is the first versions of the Su-24 bomber (ed. Т6-1) and the MiG-23 fighter (ed. 23-01), equipped with additional lifting engines for a shortened take-off / landing and a delta wing. In 1966, experimental aircraft T-58VD and MiG-21PD were built to test this concept based on serial fighter jets. Under pressure from the customer, prior to receiving the test results, the experienced Su-24 and MnG-23 were put into production. In 1967, both aircraft made the first flight. During the almost simultaneous testing of experimental and experimental machines, it turned out that this concept does not give the expected effect. According to Samoilovich OS, this is explained by the following reasons. First, jet jets of lifting engines at low speeds, reflected from concrete, are again sucked in by upper air intakes. Hot gases with a low oxygen content significantly reduced the thrust of lifting engines. Secondly, the overflow of air to the upper surface of the wing from under it, caused by the operation of lifting engines, changed the flow pattern and also reduced the carrying capacity of the wing. Thus, it was not possible to achieve a reduction in take-off and landing distances, and additional engines increased the mass and took up internal volumes, reducing the amount of fuel. As a result, both projects were radically converted into aircraft with variable sweep.
Another example. Before obtaining the results of testing the experimental MiG-21I aircraft (started in April 1968 of the year), specially designed to determine the characteristics of the lively wing for a passenger supersonic aircraft, laid an experienced Tu-144 (December 31 1968 of the year - the first flight). As a result, the Tu-144 aircraft radically changed the wing profile and corrected its shape in the plan.
The development and research of experimental aircraft in the United States has always received considerable attention. Suffice it to recall the first aircraft "X", with which at the end of 1940-x - the beginning of 1950-x. investigated the problems of supersonic flight. In 1950-1960-ies. Americans built more than 10 experimental X-series vehicles with which they studied various vertical take-off aircraft designs. Created in 1951, the experimental X-5 was the first aircraft in the world to have a variable sweep wing. Bert Rutan in the year 1979 commissioned by NASA to build an experimental aircraft AD-1 with an all-turning wing of an asymmetrically variable sweep. In 1984, a series of X-29 test flights with a forward swept wing was launched. In 1990, research on super-maneuverability continued on the experimental X-31. This list is far from complete.
In the USSR, this field of aviation science was developed much less. The “golden age” of domestic experimental aircraft fell on the 1950-1960. In 1957, for testing the vertical take-off, an experimental apparatus “Turbolet” was built, in 1963 - the Yak-36. On the basis of the serial Su-15 and MiG-21 in 1966, the already mentioned T-58ВД and MiG-21ПД were created. It was also said about the experimental aircraft MiG-21I "Analogue".
In this list, you can also add an experimental aircraft "Kvant", which was created at the Ministry of higher education, and not at the MAP. It was built in 1977 and in 1978-1984 was tested at LII MAP. Investigated the system of direct control of the lifting force, which was a maneuverable flaps, simultaneously working with the elevator while the aircraft control stick was deflected. True, the "Kvant" was forced into the category of experimental due to the fact that it blocked the road to the category of aerobatic flying aircraft. This was done by the influence and forces of Yakovlev LS, who at that time was a monopolist in the development of sports cars.
4 from 6 of the above experimental aircraft were created in large experimental design bureaus, the attitude of which to similar work was mentioned above. The only exceptions were “Turbolet” and “Kvant”, created in the design department of LII under the guidance of aerodynamics Matveyev V.N. and designer Rafaelyantsy A.N.
Organized in 1960-s. on the initiative of Myasishchev V.M. The tenth division of TsAGP, which was engaged in the study of promising schemes for aircraft, did not have any design and technological experience in the development of real aircraft.
Intensive progress in the field of aircraft in our country, which was observed before the collapse of the USSR, constantly raised questions, most of which could not be solved only by tube experiments or computational methods.
For OSKBES, the tasks were set directly by Simonov MP, deputy minister, and Shkadov L.M., head of the Tenth Main Board of the Ministry of Aviation Industry. The technical task was approved in LII and TsAGI.
The deputy minister of the aviation industry, Simonov Mikhail Petrovich, contributed a lot to the creation of OSKBES. He came to the ministry in the 1979 year, where, under him, the post of deputy minister for new equipment, pilot aircraft construction, which had been liquidated at one time, was resumed after deputy secretary general Yakovlev AS resigned. Simonov supervised the Tenth Main Office of the Ministry of Antimonopoly Policy, which was responsible for "science." Its scope included LII, TsAGI and all other research institutes of the aviation industry.
Simonov, who transferred to the ministry from the Sukhoi company, was admin. work and felt the need for design activity. Zhidovetsky K.M. said: "Mikhail Petrovich, apparently, was the only deputy minister in the entire history of the IAO, who had a drawing board in his office." Since Simonov's boiling energy was constantly looking for a way out, the order established in the MAP was rather quickly disturbed by some innovations.
So Samoylovich Oleg Sergeevich in his book recalls that at that time MP Simonov. put forward the idea that new aircraft should be developed at TsAGI, and not at design bureaus. At the same time, the OKB was only required to implement these projects. As an example, he cites the T-60 front-line bomber, the project of which was developed in TsAGI under the B-90 program (1960's bomber) under the leadership of Simonov and “lowered” to the Sukhov people in 1981.
Indeed, Mikhail Petrovich seriously “took into circulation” the Tenth (promising) department of TsAGI, and literally disappeared there. Under his leadership, in addition to the T-60, a project was developed for a single-engine experimental aircraft with a forward swept wing, similar to the American X-29. Since this plane was also supposed to be built by sukhovtsy, several young designers from the department of general types were attracted to work.
The next step, unconventional for the MAI, was the formation of the MAI in 1982 of OSKBES MAI with the direct support of Simonov, and after that - KN "Kvant" under the supervision of Yu.V. Kuznetsov, the head of SKB-S. These new design bureaus also had to be dealt with under the guidance of Simonov M.P. project research.
At the beginning of the 1980-s in Minaviaprom, work was launched on two promising programs: W-90 (1990's attack aircraft) and I-90 (1990-fighter aircraft). It was decided to involve OSKBES in the study of promising tech. solutions, the use of which would significantly increase the LTH of attack aircraft and fighters of the new generation.
For OSKBES, the first task was to determine the effectiveness of using SNNS (direct lift control system) on combat aircraft during maneuvering, aiming and targeting, including to simplify the landing technique of MiG-29K and Su-27K deck aircraft, which at that time just started to be developed. Under this program, it was supposed to conduct a series of test flights of "Quant".
Goryunov, NP, who was at that time the leading specialist of OSKBES in aerodynamics, recalled a funny incident that was related to that period. During the discussion of the details of the program with the leadership of LII, one of the OSKBES engineers drew the attention of Mironov A.D., the head of the institute, to the fact that landing on an aircraft carrier takes place without leveling and keeping up, which are usual for “normal” aviation. He was extremely surprised and at first did not even believe it. As a proof, the people of Maev offered to watch the film “The Sky Above His Head” (France), which at the time was in box office.
The picture was ordered, brought to LII. Her viewing for engineers and pilots was organized in the assembly hall of the Institute. In the film, the Super Etandaras from the Clemenceau aircraft carrier showed up in abundance, close-ups and beautifully, taking off from a steam catapult and landing on an aerofinisher. In addition, narrated about the love affairs of young pilots.
Shots from the film confirmed that the glide slope of the decline was directed strictly to the point of contact, and the slight curvature of the trajectory that occurs at the last moment was due to the influence of the proximity of the "earth".
Today, everyone knows that landing on an aircraft carrier has its own characteristics. Since it is performed "in ravens," the deck landing gear aircraft are significantly strengthened. And for Soviet test pilots, this science began with watching a French film with a light hand of MAI engineers.
In OSKBES together with the Sukhoi Design Bureau in 1983-1984. The possibility of developing a SNUPS aircraft laboratory based on the Su-15 serial aircraft was studied.
In connection with the forthcoming expansion of the range of tasks, as well as the possible increase in staff, the student design bureau in 1983 was transferred to a larger room of two cramped rooms.
The eternal problem of airplanes from the time of their appearance is an increase in take-off and landing speeds and, as a result, of the lengths of airfields, which inevitably follow attempts to increase the max. flight speed. At times, attempts are being made to somehow combat this trend. As is well known, on combat aircraft, powder accelerators are used to reduce the length of the takeoff run, and brake parachutes are used to reduce the length of the run. In this case, boosters are disposable devices, it can be said, consumables, but are forced to put up with this. In 1957, a setup was created for the aeronautical take-off of MIGT9С. The prototype aircraft, called the SM-30, was tested, but did not go into the series, since it was impossible to provide a non-aerodrome landing required by the military. The takeoff and landing capabilities of different aircraft must be of the same order.
One of the promising areas of increase in flight performance (LTH) of TsAGI aircraft was seen in the application of power systems to increase lift force (ESUPS). A well-known aerodynamic scientist, I. Ostoslavsky, also dealt with this effect. With the help of air bleeding from the RD compressor and its blowing through profiled slots, the effect of supercirculation on the wing is possible. This makes it possible to achieve values of the lift coefficient, which are substantially more than the traditional schemes of takeoff and landing mechanization provide. At the same time, the power system for increasing lift improved the take-off and landing characteristics of the aircraft.
In this area, besides the theoretical background of TsAGI in the USSR, there was little experience in the use of jet mechanization. On the MiG-21 fighters with 1964, starting with the modification of the MiG-21PFM, an ATP system (blowing the boundary layer) of flaps was installed. A similar system later began to equip Su-15 interceptors. On the An-72, which made its first flight in 1977, the Antonovans attempted to gain an increase in lift during take-off and landing by jetting jet sections of the upper surface of the wing with jets. In fact, avianauka could offer designers much more options for such mechanization.
The use of ESUPS while maintaining maneuvering and take-off and landing characteristics made it possible to reduce the area of the wing of the fighter, and this increased the maximum speed of its flight. The stormtroopers, this system allows basing on small areas near the front line.
In addition, the use of ESUPS was seen in deck aircraft. In our country at the beginning of 1980's, work was started on the creation of aircraft carriers of a new generation. The Soviet Navy was finally to receive full-fledged aircraft carriers that are armed with ground attack aircraft and horizontal takeoff fighters equipped with serious combat capabilities. Vertically taking off the Yaks, previously used on aircraft carriers, according to apt expression, "could only carry their own stars on their wings."
In parallel with the construction of aircraft carriers deck aircraft were created. In the Mikoyan and Sukhoi Design Bureau in 1983, work was carried out on the draft designs of the deck MiG-29K and Su-27K. Their high level of armament, which was equal to and even slightly exceeded one, made it possible to launch from the deck without using a steam catapult, as was the case on most foreign aircraft carriers. However, the refusal to equip ships with a catapult required some other solution for taking off strike aircraft that did not have such a high thrust-weight ratio as fighters. The most promising option to ensure unattended takeoff at a short distance was the energy mechanization of the wing. The main difficulty was that the ESUPS could not be investigated on reduced models in wind tunnels. In this case, the main element of energy mechanization under study - a slit 1-2 of a millimeter thickness, through which air is blown onto the wing, would decrease to a value of several microns. With such dimensions, firstly, it is extremely difficult to maintain the accuracy of its profiling. Secondly, and this is the main thing, there was a difficulty in observing the aerodynamic similarity, making such an experiment meaningless. To study this concept in real conditions and to work out constructive solutions for its implementation, it seemed expedient to create an experimental aircraft.
In the late 1970s. with the Americans, Rockwell International commissioned by the Navy fleet The United States built an experimental XFV-12A carrier-based fighter-attack fighter with short and vertical take-off / landing (depending on weight). Its wing and front horizontal plumage (PGO) were equipped with ESUPS. To reduce the complexity and, consequently, the production time of this aircraft, the Americans used ready-made units of serial aircraft in its design: the bow (front landing gear and cockpit) from the A-4 Skyhawk attack aircraft and the caisson part and wing air intakes from the F- fighter 4 Phantom.
Zhidovetsky was asked to evaluate the strength of OSKBES to determine the direction of work: in the interests of the topic W-90 or I-90. Within a short time, he developed and proposed experimental aircraft configurations for investigating the lift system in the interests of both directions.
When developing a new generation of Soviet fighter aircraft, it was decided to dispense with competition between Mikoyan and Sukhoi fighters, as ten years earlier during the creation of the MiG-29 and Su-27. Here, probably, the role played by Deputy Minister Simonov, who had recently left the Sukhoi Design Bureau in connection with difficult relations with General Designer Ivanov E.A. and his deputy Samoylovich OS Anyway, the task for the I-90, more prestigious for both companies, was issued by the Mikoyan Design Bureau, and the development of the W-90 was assigned to the Sukhov people. Simonov MP who returned to 1983 to Sukhoi’s firm as General Designer, had to proactively take up the topic of the promising C-32.
On the topic X-90, the experimental aircraft was carried out according to the aerodynamic “duck” scheme with two jet engines RU19А-300, equipped with flat nozzles with thrust vector control. These experimental nozzles for engines were developed in the design department of LII. On an airplane with such a configuration, the elements of super-maneuverability were to be worked out according to a program that was similar to that under which the United States was going to create an experimental X-31. At that moment, the Americans were just starting to develop it. Domestic aircraft was distinguished by the fact that the wing was equipped with a system ESUPS, which worked from the engine compressors. To reduce costs and time for the construction of the aircraft, it was proposed to use the cabin, bow, wing box, keel and landing gear of the Czechoslovak-made jet training aircraft L-39.
The design of the aircraft allowed the replacement of the wing: it could be either reverse or forward sweep. By the way, in the United States for research maneuverable capabilities of the wing having a reverse sweep created the X-29 aircraft.
Engineer Vyacheslav Khvan participated in the development of the scheme, who shortly before that graduated from MAI and came to OSKBES.
After the scheme was approved by Simonov and Shkadovy they made a demonstration model. Since the plane was going to be built in the interests of the I-90 program, it was necessary to coordinate its scheme with the leading firm on this topic, namely the Mikoyan Design Bureau. Yuri Alekseevich Ryzhov, the MAI Vice-Rector for Science, phoned Rostislav Anollosovich Belyakov, General Designer, and quite unexpectedly received an invitation immediately to come to him along with Zhidovetsky, the Mykoyan Design Bureau is located not far, across Leningradka opposite the institute.
Since it was necessary to carry a model aircraft with him, Yuri Alekseevich suggested using his own Volga. Ryzhov's “crusts” allowed him to drive to the design territory of the design bureau, but Kazimir Mikhailovich did not have time to get an ID of the Chief Designer of the IAO, so there could be difficulties with his journey to the OKB. The usual pass had to be ordered the day before, but who knew that the meeting with Belyakov would take place immediately.
Exit found sitting behind the wheel Ryzhov. He gave his ID to Casimir and said: "Tell me about me that I am a chauffeur." Passing drove smoothly.
The first reaction of Belyakov, after he saw the model brought in, was a surprise, after which he tried to find out how information about the development of his advanced 1.42 fighter jet was leaked to the MAI. He calmed down only after he noticed that the OSKBES car has one keel, while the 1.42 had two.
When almost all of those. the issues related to the “improvement” of the scheme with its implementation were resolved, suddenly a non-technical problem arose. It was 1982 year, the “mode” was strictly observed, and the level of secrecy of the scheme of this aircraft, taking into account the “neck” of the program, in the interests of which it was created, was recognized as high. For security reasons, student design bureaus could not be allowed to work on this topic. There were two ways out of this situation.
Either the design bureau changed its status, becoming experimental without a student component with all the ensuing consequences, or it continues to engage in an experimental aircraft on W-90, which was developed in parallel with the first theme by Zhidovetsky and the scheme of which didn’t carry such secrecy.
Zhidovetsky and Ryzhov, after weighing all the pros and cons, chose the second path. The topic was given the name "Photon".
In shaping the look of the aircraft, more than twenty different layouts worked. One of the first versions of the experimental aircraft "Photon", arranged at the suggestion of TsAGI Zhidovetskim, had a straight wing, a traditional aerodynamic layout and located in the nose of the TMD-10B TRD. The work of ESUPS was provided by two auxiliary power units (VSU) of the AI-9, located on the wing in the gondolas. The main landing gear was cleaned in the same gondola. Nose - was removed in the fuselage. The T-shaped tail unit allowed the stabilizer to be removed from the zone of significant oblique flow behind the wing, which is equipped with ESUPS. This scheme was rejected by LII, since blowing a wing from a screw from a screw would spoil the flow pattern, which is undesirable for an experiment.
After that, they developed a variant of the "Photon" having an AI-25 turbojet engine mounted above the central part of the fuselage, and a two-fin exploded plumage. This arrangement was also discussed with LII and TsAGI.
As a result of all these preliminary works, Zhidovetsky was visited by the idea to combine both versions of the power plant - turret fuse and turboprop engines, in case of refusal of additional AI-9. For the needs of ESUPS, air could be drawn from the secondary circuit of the AI-25T turbofan engine. In addition, Zhidovetsky in this layout laid the decisions that would allow in case of successful completion of the experimental program to use the machine as a prototype of a serial light attack aircraft.
"Photon", according to Zhidovetsky KM, was to occupy its own niche among existing combat aircraft and be a kind of "scalpel" in the hands of the military, which will be particularly effective in local conflicts. It was assumed that these aircraft will be used to respond to the request of the ground forces, based around the front line on field airfields of small size. To do this, the aircraft must have excellent take-off and landing characteristics. The energetic mechanization of the wing of the Foton aircraft was to provide properties unprecedented for this class of machines.
To clarify the urgency of this concept of combat aircraft can be explained by the following example. During the Balkan 1999 conflict, NATO fighter-bombers who bombed Serb military facilities in Kosovo took off from Aviano's air base (Italy), which was several hundred kilometers away. At the same time, the error of the navigation calculations was so large that several times air strikes were inflicted on columns of Albanian refugees in Macedonia, for the sake of protection of which, in fact, NATO combat operations were conducted. Attack pilot who is based in tens, not hundreds of kilometers. from the line of combat contact, it is unlikely to confuse the country to be bombed.
By the end of the 1960's. military experts of the leading countries of the world came to the conclusion that the accuracy of destruction of ground targets from supersonic fighter-bombers with missile-bomb armament is not high enough. The high speed of these aircraft gives the pilot very little time to aim, and poor maneuverability does not allow to correct the inaccuracy of aiming, especially when striking low-profile targets. Then in the United States appeared subsonic maneuverable attack aircraft A-10 company "Fairchild" (1972 year), and in the Soviet Union - Su-25 (1975 year).
By the way, the concept of “field” basing near the front line was laid by the designers at the initial stage of creating the Su-25. It was assumed that the attack aircraft will be equipped with two dual-circuit, relatively small, AI-25 engines (installed on Yak-40 passenger planes), it will have take-off weight 8 thousand kg, combat load - 2 thousand kg, operating speed range - from 500 to 800 km / h and range - 750 km. The main thing - the aircraft must be operational means of supporting ground forces. The command of the Ground Forces, understanding this, fully supported the creation of the aircraft, while the Air Force for a long time towards him showed complete indifference.
However, jealousy on the part of the Air Force Command, the reluctance, together with the aircraft, to give the ground vehicles airfields with infrastructure and regular personnel units led the customer to take up the project seriously. As a result of repeated demands for increased speed and combat load, the Su-25 began to take on the 4th board. kg of ammunition, and its maximum speed increased to 950 km / h. However, having transformed into a multi-purpose aircraft from an “battlefield” aircraft, Su-25, with a twice-increased take-off mass (17,6 thous. Kg), lost its ability to base on minimally prepared small areas near the front line, instantly “working off” the targets on ground requests. To shorten the response time during the war in Afghanistan, it was necessary to organize the airborne duty of attack aircraft.
Light attack aircraft "Photon" was really to become an aircraft directly supporting the ground forces.
The main feature of the "Photon" scheme was a spaced-off redundant power plant, which consisted of a TVD-20 turboprop engine located in the forward fuselage and an AI-25TL turbojet located behind the cockpit. Such placement of engines reduced the likelihood of their simultaneous defeat from enemy fire, and also provided additional. protection for the pilot who sat in the titanium welded “bath”, as in the Su-25. Inside the design office, the project immediately received the second name - “Push-pull”.
According to Kazimir Mikhailovich, for an attack aircraft that constantly works in conditions of powerful fire resistance, a low profile scheme is preferable by many criteria. The structural elements of the low-lying horizontal tail and wing protect the engine and pilot from fire from the most probable directions from the ground.
It is also known that the plane of the “nizkoplan” scheme provides the crew with much greater safety during an emergency landing with an unreleased landing gear, the probability of which for an attack aircraft is very high. This can be explained by the fact that the wing center section is a very solid construction, which takes on the load, both in flight and during a forced landing, thereby protecting the crew. For an aircraft with a high-profile circuit for this case, the bottom of the fuselage is additionally enhanced. The wheels of the main chassis of the "Photon", half protruding from the niches, also increased the chances of a safe landing in the event of a malfunction of their release system.
To date, the most common and effective means against low-flying aircraft are MANPADS (man-portable air defense systems) such as Igla, Strela-2 (Russia) and Stinger (USA). Practically all of them are equipped with an optical infra-red hsn, which reacts to the hot nozzle of a jet engine, and are mainly launched into the rear hemisphere of the target.
OSKBES employees at the aircraft "Foton".
Ritual Square MAI, 1986 g
Ritual Square MAI, 1986 g
The layout scheme that Zhidovetsky chose for “Photon” also took this into account. The redrawn inverted scheme with the location of the AI-25 engine nozzle above the tail boom and the low-lying horizontal tail with separated keels made it difficult to capture the target with thermal seeker from the most probable firing angles. The vertical two-tail unit also increased the combat survivability of the aircraft, meeting the requirement for redundancy of the main structural elements.
For the "Photon" chose a chassis scheme with a tail bearing, since it provided a higher throughput. True, an aircraft that has such a landing gear scheme is more difficult to control during takeoff and landing. Firstly, the pilot must take special care to maintain the direction of run and run, as the aircraft tends to spontaneous reversals. Secondly, since the start of the run begins with the parking value of the angle of attack of the wing, the pilot must first give the control stick away from himself, tearing off the tail and reducing the angle of attack (and therefore resistance), and only then, having gained the necessary speed, pulling the handle towards himself take off the ground.
Zhidovetsky KM, to overcome these shortcomings of the chassis with a tail bearing, a circuit with a loaded tail pillar was used. This meant that the tail wheel accounted for the largest part of the aircraft’s mass than is customary. Thus, the necessary directional stability was ensured during the takeoff and run of the aircraft. And the significant starting thrust-carrying capacity of the Photon and the possibility of separation by turning on the ESUPS at the required moment, when the necessary takeoff speed was reached, allowed us to take off from three “points”. These factors made it possible to easily master the new aircraft to pilots of medium qualification, who had not even flown on planes with a tail wheel before.
Despite the location in the nose of the TVD-20 engine, the layout provided excellent forward-down view of the pilot, which was certainly necessary for an aircraft of this purpose. All the windows of the cockpit canopy were made of bulletproof glass. The cockpit was equipped with an ejection seat.
Both engines, AI-25TL (kg 1700 thrust) and TVD-20 (hp 1375 power), operated at maximum speed during takeoff. The air that was taken from the second loop of the AI-25ТL engine ensured the work of jet wing mechanization during take-off and landing.
Also, both engines were used for quick access to the goal and care after completing the task. The loitering mode in the target area or cruising flight was provided by a more economical TVD-20, while the AI-25TL was switched to idle mode, for less fuel consumption.
The need for an attack aircraft of such an economical regime, which provides a longer flight time, was identified at the last stage of the combat operations of the Soviet troops in Afghanistan. In the winter of 1988-1989, the columns of the Fortieth Army retreated along mountain roads to the Union from Afghanistan. Helicopters and attack aircraft Su-25 covered the withdrawal of troops from the air in case they were attacked by ambush columns on the march. The remoteness of the airfields located on Soviet territory, as well as the high fuel consumption of the RD, did not allow the aircraft to remain for a long time over the concealed troops. That is why at the end of the 1980-x and the beginning of the 1990-s, Sukhoi’s company, within the framework of the W-90 program, also worked out a draft attack aircraft, which was to be equipped with a pair of fuel-efficient turbojets.
Since the take-off mass of the "Photon" was 3 tons, and it had a rather unusual appearance, one of the OSKBES wits called it "Triton."
The armament of a light attack aircraft was to consist of free-fall aerial bombs, uncontrolled air raids for firing at ground targets, and guns in underwing suspended containers. In the case of the use of the aircraft as a fighter helicopters and for self-defense, he could carry self-guided missiles "air-to-air" melee equipped with infrared seeker. Also, the aircraft could be used to destroy remotely piloted aircraft.
The design of the aircraft and the carefully executed model were demonstrated at Piyrogovka at the headquarters of the air force, as well as at other instances of the military department, but everywhere ran into the same reaction: “Everything that carries less 5 tons of bombs is of no interest to us!”. The military does not need a scalpel. Much more convenient to use the "club".
So, to enlist for the implementation of the project "Photon" support of the military did not work. The customer - the Tenth Main Command Board - believed that the creation of an experimental aircraft would be very expensive. It also seemed to TsAGI that for solving the set task - research of ESUPS - this scheme is unnecessarily complicated. LII categorically opposed the use of a screw power plant.
Also, the fate of the TVD-20 remained unclear. It was developed under the An-3, but with the termination of this program, the question of fine-tuning and serial production of the engine hung in the air. Zhidovetsky proposed to develop a simplified version of the aircraft. The technical assignment for the aircraft was developed at LII and TsAGI, and 10 was approved on July 1984 by the Deputy Minister.
During 1984, a draft design of an aircraft of the same name was developed, but a completely different scheme. We chose the RUNNXXА-19 jet engine (kg 300 thrust) as the main engine. Since the modifications required for air extraction could not be coordinated with the engine design bureau, the X-NUMX of AI-900 gas turbine units had to be installed on the plane for jet mechanization. On the one hand, this seriously complicated the design, but on the other hand, an autonomous air source made it possible to change the ESPS parameters regardless of the main engine mode. Four AI-4 placed on the sides of the fuselage under the fairing in pairs.
Goryunov Nikolai Petrovich recalls that the developers were very worried about the single figure in those. characteristics AI-9 - the maximum time of continuous operation of the unit. According to his passport, this figure was equal to 45 seconds, while on the Photon he needed to work continuously for much longer. To resolve this issue and get detailed documentation, a group of USC-BES workers was seconded to the Lotarev Design Bureau in Zaporizhia.
Engine KBs could not answer what caused this restriction, and whether its excess is possible. When Muscovites were already desperate because of a deadlock, one of the oldest employees of the design bureau was found who remembered that in technical terms the figure was 45 seconds. appeared only because it was necessary for those. task Yakovlev, for which was created AI-9. In fact, the unit could continuously work up to the full use of the resource.
On the plane for the purity of the experiment was used a straight wing without narrowing. To reduce the influence of interference with the fuselage on its characteristics, the wing was made mid-range. He was "untied" from the chassis, setting it on the fuselage, for the same reasons. The wing was developed in TsAGI 16 percentage profile of the P-20. The wing in the power relation represented a caisson divided on scope by detachable consoles and the center section. Replaceable rear and front modules of energy mechanization were installed on the console.
So that the powerful bevel of flow behind the wing, caused by the effect of supercirculation, did not reduce the efficiency of the horizontal tail, it was carried to the top of the keel of a large area. To ensure longitudinal balancing of the aircraft on take-off and landing modes with a working ESUPS, the horizontal tail was given a relatively large area, which was almost 30 to percent of the wing area and 12 asymmetric inverted profile.
In order to simplify the design and taking into account the fact that the aircraft will mainly work out takeoff and landing modes, it was decided to make the landing gear non-retractable.
The design of the aircraft was high-tech. The fuselage contours implied a minimum of double curvature skins. They were made of fiberglass. All loads were perceived by the upper part of the fuselage, a kind of “ridge”, which was divided into layouts into the cabin, the middle part, which serves to accommodate the fuel tank, and the tail part. The wing center section was attached to the middle part of the fuselage; under the tail section, the RU19А-300 main engine (developed for the Yak-30 training aircraft, used as an auxiliary power unit on the An-26 and An-24РВ). The main landing gear were attached to the wing center section, to which also mounted on the 2 unit AI-9 (used as an auxiliary power unit on the Yak-40) on each side. The entire lower part of the fuselage consisted of opening hoods and removable skins, which provided excellent access for servicing a bulky and complex power plant. The air intake of the main engine was carried forward by the nose strut of the chassis to prevent foreign objects from getting into the UPU, tossed by the wheel. On a horizontal platform, test equipment was placed in the nasal fiberglass fairing, the approach to which was ensured by sliding the entire fairing along the sensor bar of the angle of attack, slip and speed forward. The front compartments of the side fairings were also used for testing equipment. The flat bottom surface of the nose cone at high angles of attack was supposed to compress and align the air flow that entered the engine air intake.
The central control post was taken from the MiG-29 fighter. The aircraft installed an ejector seat K-36ВМ class «0-0», used on aircraft with GDP. In the tail of the fuselage was placed container antispin parachute.
Estimated take-off weight of the "Photon" - 2150 kg. The maximum speed should have been 740 km / h and the rate of climb of 23,5 m / s. Without ESUPS being turned on, the minimum speed was 215 km / h. In the case of using ESPS, it should have been almost halved - 125 km / h.
At the All-Union 1984 / 1985 competition of the school year, the Photon project for the best scientific work among university students took second place. Bobrov A., Dunaevsky A., Svinin S., Merenkov S., Serebryakov A., Alexandrov I., Chernova N., brothers Sabatovsky S. and Sabatovsky A. (24 MAI student) received cash prizes and medals of the competition as authors of scientific research work "Project of the experimental aircraft" Foton ". Also noted the leaders of the work Zhidovetsky K.M., Kozina Yu.V., Goryunova N.P. and Khvan V.T.
As already noted, it was impossible to work in a small wind tunnel on smaller models of ESUPS due to the difficulty of observing the aerodynamic similarity, and it was too risky to lift an experimental machine with such an unexplored circuit right into the air. In this regard, the first copy of the "Photon", the construction of which began in 1985, was intended for purging in the natural wind tunnel TsAGIT-101.
To study the pattern of flow around the aircraft during operation of the AUPS, there were more than 1200 points for measuring static pressure on the wing surface, fuselage in the wing zone and tail unit. The pressures from these points were removed from the aircraft through pneumatic switches to the racks of aerodynamic weights and then to measuring devices that were outside the working area of the pipe. The leading engineer of OSK-BES, Konenkov Yuri Stepanovich, for the Foton pipe version, developed and manufactured a remote control system for steering surfaces, bypass valves of the pie system and flaps. Each controlled surface was equipped with a position sensor.
Also, the first copy served as a model for working out the layout of the cabin, the placement of equipment and components of the control system. All the main parts were made in three sets: for the pipe, static and flight copies of the aircraft. True, a copy for static strength tests and a flight copy were to be made at the end of a complex purging program. The difficulty was that the design of the aircraft involved the use of more than a dozen variants of jet wing mechanization combinations. During the assembly of the "Photon", the workshop of experimental aircraft of the EOZ MAI was under the direction of Mikhail Tetyushev. Lead designer for the assembly of the aircraft - Demin Vadim.
Since the production capabilities of the MAI Experimental Experimental Plant were very limited, they organized extensive cooperation with the aircraft plants of Moscow. This involved Kuznetsov Gennady Viktorovich. At the Sukhoi pilot plant, glass was made for the folding part of the cockpit canopy, as well as most of the curved parts, such as wing loops, rudders, tail pieces and fuselage skin. Electroplating of all large platings and part of the bent parts was carried out at the Ilyushin pilot plant. Nasal fiberglass fairing glue on the Moscow Helicopter Plant named Mile in Panki. Screw locks for numerous opening hoods were ordered at the Gorky aircraft factory, where they went to the MiG-31 and MiG-25.
For the "trumpet" instance of the "Photon" chassis was not required. The aircraft in a full-scale pipe was supposed to be placed on racks of aerodynamic weights; at the same time, through them, air was supplied under pressure, which ensured the work of energetic wing mechanization.
The development of a regular chassis was to be carried out at the second stage of work - during the creation of the Foton flight copy.
"Pipe" instance to move on the ground was equipped with a technological chassis. To do this, use the front and main rack Yak-18T. Since the main pillars of the Photon, unlike the Yak, were mounted on the fuselage, and not on the wing consoles, they had a small “camber”. In this regard, the wheels of the Jacob pillars were set at an angle to the vertical. For all those who saw the plane for the first time, this raised puzzled questions. Nevertheless, this “non-native” chassis made it possible for the “Photon” on the trailer behind the truck to get under its own power to Zhukovsky from MAI, which is approximately 80 km.
Together with the aircraft produced several wing replacement modules ESUPS.
The construction of a “pipe” instance of the “Photon” was completed in June 1986 of the year at the MAI Experimental Experimental Plant, after which the aircraft was sent to TsAGI. As always, they drove at night along the ring road around Moscow at low speed, accompanied by traffic police. I remember the moment when, at about five in the morning, we reached the bridge over the Pehorka, found ourselves in a cloud of fog that had accumulated in the valley of the river. Visibility was less than a couple of meters, and therefore low speed was reduced to pedestrian.
So, TsAGI began to prepare the plane for testing in the T-101 tube. A team of OSKBES engineers went to TsAGI on a long trip together with "Photon". Demin Vadim was the leader in aircraft design, Kozin Yury Vladimirovich and Serebryakov Alexander were responsible for the operation of the pneumatic system, Filippov Volodya was in charge of the measurement system. Vyacheslav Khvan was the scientific adviser from the MAI. Aleksey Nikolayevich Pakin was appointed the leading expert from TsAGI, and Albert Vasilyevich Petrov, the leading aerodynamic power engineering specialist in the USSR, provided general scientific guidance. For the entire time of the test, “nurse” for the Mayev brigade was Filin Alexander Sergeevich, the leading engineer from preparatory T-101. The owl taught all the subtleties of preparing the work in the pipe and the work itself.
The first attempt to test the pressure of the pneumatic system of the aircraft discouraged designers. In preparing for it, everything was done carefully, with the observance of all precautionary measures. A high pressure could “inflate” the structure, and a safety valve otterirovany to the desired pressure was absent. He also had to develop. It was decided to place Filippova Volodya with an ax near the hose, which supplied the plane with air, in order to cut the hose at danger. How surprised the whole crew was when the gauge needle did not even flinch after the air supply. Despite the fact that the pneumatic system of the aircraft was collected on the sealant, it did not hold pressure. Complete elimination of leaks took more than one month.
Before installing the plane into the pipe, it was necessary to work out the ESUPS in "static". After eliminating the pressure loss the plane in the liner “sang”. It was a high frequency vibrated plating that formed a gap. In addition, under pressure, the thickness of the gap between the fasteners doubled. Two millimeter dural lining were replaced with three millimeter stainless steel.
The selection of the profiling of the gap, as well as the relative positions of the flap and the gap, required special care. In order to visualize the spatial spectrum of the flow around and confirm the sticking of the jet to the flap in all ranges of its deflection angles, special clamps with silk fibers were made. A lot of time was spent on providing the same spectrum of mechanization flow along the entire span of the wing.
With the help of miniature sensors, the total pressure in the slit and supply lines was measured. Since the end of the 1940-s, the TsAGI gas dynamic test experience has been almost completely forgotten. I had to look for old specialists who still remember the methods of conducting such experiments and processing the results. Such a specialist was Azat Sadgeevich Chutaev, who provided substantial assistance in conducting the Foton tests.
It turned out that the plane is only half the battle. It turned out that the instrumentation equipment of TsAGI does not provide an experiment. For example, she could not simultaneously measure pressure at a thousand (and even more) points on the surface of an aircraft. Work had to start with the creation of such equipment.
In order to visualize the velocity field behind the wing, a lattice with silks was made, which could be installed at various distances behind the wing, showing the influence of the flow slant on the tail and the flow pattern.
The engineers of the MAI brigade during their work at TsAGI in general received more than 20 certificates for inventions in the field of aerodynamic engineering.
During aircraft purging, a complete set of aerodynamic characteristics for one of the configurations (landing or cruising) is obtained in one run of the pipe. The aircraft is driven through all the slip angles at each angle of attack, with a step of a few degrees. The characteristics of the "Photon" for each combination of angles of attack and slip also depended on the air flow in the power system to increase the lifting force. In this regard, the number of fixed test points increased by an order of magnitude. Also, the program provided for the study of several variants of replaceable modules for the mechanization of the trailing and leading edges of the wing.
Blowing was carried out on the front edge of the wing, on aileron, on the usual rotary flap (up to the deflection angle of 180 degrees), on the round rear edge of the wing. Also tested round rear edges of different diameters. The latter was of particular interest, since the wing design was simplified and facilitated (due to the absence of moving elements - ailerons and flaps), the combat survivability and reliability increased, it became possible to use the entire wingspan to increase the bearing capacity. In this case, the roll control was carried out by asymmetric blowing on the wing, to which a large blowing program was dedicated. True, they feared that in cruise flight the round rear edge of the wing would cause an increase in resistance. However, in the process of testing, we found a way to solve this problem without constructive complications, practically “for free”.
The effect on the flow around the wing of the flow turbulators (spoilers) and their optimal location along the wing chord was also investigated. In addition, a study was conducted on the effect of different wing tips and partitions between aileron and flap sections.
In addition to the original configuration, the aircraft was flushed with horizontal tail, transferred to the fuselage from the keel. The characteristics of the air intake and its canal were also investigated, counting on the construction of a flight copy of the Foton aircraft. Since TsAGI was interested in the work of ESUPS in the jet of the screw, they planned to blow the "Photon" with a screw installation placed in the pipe in front of it.
With the "Photon" in terms of purges in the T-101, not one of the aircraft previously built in the USSR could match. Tests conducted in two shifts. No one counted the number of "pipe" clocks, however, this example is typical: when it was required to carry out tests in the pipe of another plane, the Photon was briefly filmed, the guest was quickly blown and the owner was installed on the scales again. The main competitor of the "Photon" for "pipe" time at that time was the MiG-29.
Before each installation in the pipe, long hours were spent on ground tests and careful debugging of the next configuration of power systems to increase lift in the “statics”.
As a result of the tests, they obtained a huge in volume and material of a unique ESPS value. After all, even today, it is impossible to obtain similar results using purely computational methods. This is the only such deep study of this trend in the USSR. The participants of this work have accumulated not only theoretical, but also design and technological experience (which is very important!) In the field of energy systems for increasing lift.
In short, you can give two figures that give a qualitative picture of the results achieved. The efficiency of power systems for increasing lift is characterized by a recovery coefficient on the total pressure profile. Its value shows the cost of energy that must be brought to the stream flowing around the wing in order to maintain a continuous flow. For a typical configuration, the usual rotary slit flap, deflected at an angle of 60 degrees, this factor for "Photon" is equal to 0,05. For comparison, on the An-74, the Antonovites reached twice the value, and therefore less effective. Judging by the appearance at the MAKS-2001 An-74ТК-300 air show with engines that are traditionally located under the wing on the pylons, the gain from blowing part of the wing was much less than the loss in ease of engine maintenance.
The maximum lift coefficient, which was obtained during the experiments on the "Photon", was 3,6. It is necessary to clarify that this is not the dry-air profile obtained on the wing compartments of infinite elongation in wind tunnels. This is the coefficient of the actual layout of the aircraft with the fuselage, which "eats" a significant part of the wing span. For comparison, the Fowler Three-slot Flap can be equal to 3,5, however, the complexity of the actual design of such a flap is much greater than ESUPS.
According to the results of the tests, "Photon" developed two special aerodynamic profiles of the wing, which allow to obtain the best performance with power systems to increase lift. She has also been tested at TsAGI.
Funding for the topic from the MAP began to expire already in 1988, and in 1989 it stopped completely. It became clear that the construction of the flight copy of the aircraft "Photon" will not take place. Despite this, the military, who were interested in the results of this topic, continued to find funds for the continuation of the testing of the Foton pipe sample until 1993. A change in the country's political course, as well as a reduction in research expenditures (in various sectors of science, on average twenty or more times), did not completely allow the implementation of the Photon program.
Undoubtedly, the work on "Photon" was a serious test of the scientific design level for the OSKBES MAI team, as well as an important milestone for its history. And if it were not for the collapse of the USSR and its aviation industry, this interesting project would undoubtedly bring it to the stage of a flight experiment, and other equally interesting and serious developments would follow.
The introduction of ESUPS in aviation can be compared with the revolution that was caused by the appearance of landing pads and flaps in 1930 on airplanes, and in 1960 - the variable sweep of the wing. The advantages of ESUPS compared to variable sweep and take-off and landing mechanization are its speed, relative structural simplicity, as well as higher achievable values of the lift coefficient. Also ESUPS can be used in different combinations with them.
The results of the research on "Photon" were laid in another project of Zhidovetsky - the jet administrative aircraft "Aviatika-950", which was developed in 1994-1995 in the framework of the Aviatika concern.
Aircraft performance characteristics:
Modification - Photon;
Wingspan - 7,32 m;
Length - 8,27 m;
Wing area - 7,32 m2;
Empty weight - 700 kg;
Maximum take-off weight - 2150 kg;
Engine type - turbojet engine RU-19-300;
Thrust - 900 kgf;
Maximum speed - 740 km / h;
Flight duration - 1 h .;
Practical ceiling - 10700 m;
Maximum operating overload - 6,85;
Crew - 1 man.
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