Once again, the need to remind you that the bulk of the disk imaging technology Raptor fighter so far is closed and available only to certain U.S. military personnel who have the proper permits. For this reason, all of the following information has been taken from the open sources, and may not be one hundred percent compliance is the real current situation. In addition, a number of technical problems or difficulties the F-22 is connected directly to the monetary side of the project, because the second part of this article may overlap with the first and add to it.
The philosophy of balance
Since the mid-80s, the program ATF (Advanced Tactical Fighter — «Progressive Tactical Fighter") was carried out in accordance with the refreshed monetary ideology. The military does not have to seek any of the properties at any cost, but it is very probable flight and combat characteristics, which can be achieved at a cost of 1st plane at 35-40 million dollars. At the time, such an approach has received a lot of positive reviews, but in practice it turned out more difficult. In the light of new technical solutions coming form the F-22 became known as balanced. At first, it concerned the overall balance of features and price totality. In a more specific embodiment of the concept of equilibrium sought without much harm, "make friends" at once a few features and technical aspects. So, good maneuverability needed to connect to the low signature, low visibility and proper contour of the airplane with her good with supplies of fuel and weapons, and so on. In general, the view is nice and fascinating ideology threatened the balance of different traits weight problems for engineers. The Pentagon sought as before very probable properties, to ensure that it was sometimes very hard.
And yet the designers Bureau "Lockheed Martin" managed to partly meet the requirements of the military, and to give the aircraft a maximum capacity that could provide data in weight and size and monetary framework. First, let the brakes on stealth. According to reports, the fighter F-22 has an effective area of scattering at the level of 0.3-0.4 square meters. In contrast to the evidently poor F-117A, F-22 fighter was placed first as a fighting machine with good flight data. Stealth received the least value, making ready plane received a special fuselage and wings, at the same time, do not have significant differences from most fighters. In any case, in its general form "Raptor" is really like a plane, not a weird iron, as it was with the F-117A. Inconspicuous, in turn, is achieved by means of secondary, such as monotonous orientation of edges are at an angle to the longitudinal axis of the aircraft or the collapsed fins outwards. When developing such kind of employees aerodynamic offices Lockheed and NASA had to seriously face the "balance." Yet, their published cooperate comparable small ESR and good performance data.
Stealth aircraft also had the highest balance and maneuverability. According to the accepted opinion, fighter fifth generation to be super-maneuverable, which is usually achieved by using engines with thrust vector control. On the F-22 uses unique rectangular nozzle flaps deflected. Immediately to the configuration of the thrust vector nozzles provide such an effective lowering of the temperature of gases to throw out. As a result, came to achieve a reasonable balance between maneuverability and visibility in the infrared spectrum. Employees of companies Lockheed Martin and Pratt & Whitney were able to make the power plant, one hundred percent satisfying the requirements of the military. At the same time, the original rectangular nozzle was a pretty complex in engineering terms.
In general, the need for low visibility in the radar spectra seriously affected the course of the entire first phase of the project, related to the definition of the common features of the future aircraft. The balance between the flight data and discreet led to the use of a number of diverse technical solutions. For example, initially intended to make only the power set of wings made of composite parts on the basis of carbon fiber reinforced plastics. This approach could further reduce visibility. But coming from the test results, I had to change most of these metal parts. As it turns out, carbon fiber spars have the least strength in store, if titanium is also more complex to manufacture and are suitable for almost frisky substitution in the criteria of the military workshop. Of course, the change in the material details of the power set resulted in a severe alteration of all related components and assemblies, is also palpable complicate the creation of the frame plane.
All I carry within themselves …
The corresponding feature of the F-22 was the lack of constant external suspension set up for use in combat. Under the wing of a fighter as required can be set to four pylons mounted fuel tanks or for missiles. But in this case, the ESR characteristics significantly increase aircraft, the radar display and it looks approximately the same as more old F-15 or F-16. Because of this, a real combat situation it is recommended to use only the internal suspension.
The introduction of only the internal volumes, coupled with the required dimensions and masses of the promising aircraft was one of the most challenging goals in its development. If the internal fuel tanks were all more or less just for them and gave almost all the available volumes, the transportation and the use of weapons had to tinker. In 1-x, it was necessary to allocate amounts under gruzootsekah. The bulk of the weapons placed in the middle part of the fuselage, immediately after vozduhopoglotitelyami. The size and facilities of the gruzootsekah allow you to position it to 6 AIM-120 missiles. Another two of the smallest size placed at the edges of the core. In each of them there is room for only one missile AIM-9. Second problem of the development of gruzootsekah was to safeguard the use of weapons in all criteria. There was need for a device that can push the boundaries of the missile interior of the aircraft when flying at tremendous speeds and at least some congestion.
In light of the technical data of different types of missiles had to make a descent two launch devices. For more languid an
d large AIM-120 developed a buoyancy device that can throw a rocket from an aircraft at supersonic speeds and across a range of permissible overloads. This unit is a system of pneumatic or hydraulic cylinders. First at a speed of about eight meters per second displays a rocket beyond gruzootsekah "punching" the boundary layer of air. Second, in turn, provides the uncoupling and withdrawal of ammunition away from the aircraft. The already complex system of ejection gun was complicated by the fact that in a combat situation requires a little time, extending from pressing the start button to start self-missile. After several months of complex research in wind tunnels and huge costs managed to bring the work to a level of 0.8-0.9 ejector seconds. The military initially wanted to get more frisky device, but subsequent work in this area have been stopped because of the strength characteristics of missiles. AIM-120 comes with an overload of gruzootsekah about forty units. Greater acceleration due to the release can lead to damage of the munition, right up to its complete inoperability.
Second missile ejection system created for lighter AIM-9 and is based on a different principle. Before launching the missile falls from gruzootsekah, the front part of it pushed harder than the back. Trapezoidal unit that hosts the restraints do not have any means to shoot missiles — when the motor is without the help of others coming to the guide. Indoor units are protected by a special aircraft gazootboynym guard. Totally understandable that both options launchers even more difficult than usual underwing pylons beamed holders. In this regard, this complexity and construction, and maintenance. From the designs of old times and the ejector trapezoid do not differ only "attitude" to the pilot. Him as before befitting quite easy to press the button. The corresponding feature of the new complex machines was non-repudiation of them. Requirements for stealth just do not give to simplify the design and service of aircraft through the use of the least complex ignition systems.
It should be noted fighter F-22 could still bear arms on the outside of the suspension. But, as already mentioned, with all this very aggravated EPR aircraft also likely some difficulties with the aerodynamics. At the end of the 90 pylons for drop tanks or weapons have been harsh processing. During the tests, it was found out that the first version of these units has increased the possibility of flutter. According to reports, during the alteration has been changed not only the shape of the pylons, and their construction. The development of new attachments engineers "Lockheed Martin" tried to ensure the least visibility of the aircraft even when using pylons. To this end, according to some sources, they are made of a continuous carbon fiber parts. Given the fact that the pylons can be discharged for vsepolnotsennyh piloting skills and stealth, this design does not look particularly successful at first, in financial terms. In the course of the following upgrades planned to come back to this issue again and improve pylons for external suspension.
Hard to be independent
One of the main requirements for the newcomer aircraft was to simplify maintenance and preparation for departure. To this end, in order to accelerate the start-board systems, F-22 equipped with an auxiliary power unit. This unit provides electricity to start the plane engines that drive the main generators, hydro and Pneumopumps. It should be noted, VSU fighter was one of the most trusted sites. The last big problem with the auxiliary power unit ended in the late 90's, when a couple of times had to endure another test flight. Then a low-power gas turbine unit has been significantly improved and continue to huge problems did not deliver.
The second method was to facilitate the maintenance of life-support system to become pilot, and specifically its part, is responsible for the supply of air and oxygen. On all U.S. aircraft to F-22 pilot gets oxygen for respiration of the respective cylinders. But such a system asks constant refueling or substitution of the internal tanks of gas. Since the F-22 had to be able to patrol the long and very frisky preparation for the flight, the customer and the developer ultimately concluded that the need for the introduction of oxygen regeneration. To this end, the company was ordered Normalair Garrett complex OBOGS (On-board oxygen generating system — the system-board oxygen generation). As is clear from the name, OBOGS created for processing pilot exhaled gases and restore the normal amount of oxygen. So Makar, all service the oxygen system is reduced to a timely substitution of regenerating tapes and cleaning the filters. As an emergency breathing system on the F-22 installed additional units of the complex EOS «classic» reference: oxygen tank and related equipment.
Apart from providing a specific pilot oxygen system OBOGS responsible for protecting the pilot from overloading. The structure of the life support systems combined suit comes Combat Eagle, uniting in itself anti-g, high-altitude-compensating and heat characteristics. Pretty easy design a suit in the middle of other things, led to the impossibility of repairing it in the criteria of the drill. Because under certain damages suit Combat Eagle simply written off and the pilot gets a new one. But, as it turns out, a small maintainability antigravity a suit and complexity of the regeneration system was not far the largest neuvvyazkami new fighter. A few months back, it became clear that a lot of problems in the field of life-support pilot brought one small detail that at first no one thought in something incriminating.
Choking on overload
In the middle of November 2010 in Alaska crashed combatant fighter F-22 pilot John Haney died. A prerequisite for the accident admitted failure of the system OBOGS, caused by hypoxia, due to which the pilot lost consciousness and did not have time to include a spare EOS. Because of this, all aircraft have updated the software — now the inclusion of spare respiratory system is done automatically. However, these alterations are not one hundred percent guarantee of getting rid of problems. In the upcoming pilots combat units not once complained about the severe difficulties in flight: in some kinds of cases they feel strangulation. After the regular commission proceedings and the U.S. Air Force Lockheed Martin learned that strangulation is a prerequisite synchronism respiratory system module OBOGS, in charge of the pilot supply pressure of oxygen, and units of Weight compensated overload. Dissynchronization of these parts of the complex life-support chest and tummy pinched pilot suit on the outside, but inside it is not offset by sufficient pressure is the pressure of the oxygen supply. Just a few seconds of such problems in certain circumstances, lead to atelectasis — spadenie alveoli. This phenomenon, in most cases does not lead to severe health dilemmas, but the pilot requested a couple of days extra rest. In addition, some pilots, having undergone a short-term suffocation, filed a report with a request to remove them from flying an F-22 to fix all the problems.
In July 2012 the Pentagon told the official dealer of the results of the investigation. It w
as found that the dilemmas with strangulation was povinet system module OBOGS, was responsible for the proper functioning of the overload of a suit Combat Eagle. Specifically, not the module, and one of its parts. One of the valves of the pumping a suit may not be suitable for use. He missed the free air inside the suit, but did not provide a tribute to the speed bleed. As a result, the output of the respiratory maneuver with the overload module OBOGS reduced oxygen supply pressure to the desired value, and the suit remained inflated until such time as the air is not etched out of it with such a pace, which could provide the ill-fated valve. Even before the results of the investigation to the air supply system of the overload was markedly refined and re-tested for proper operation. By the end of this summer, was created a set of new parts designed to re drill the F-22. By the beginning of 2013 are all available in the U.S. Air Force fighter jets will be retrofitted with new components.
All these prepyadstviya a part of the overload set OBOGS entailed not only a health problem pilots. Starting with the disaster of 2010, F-22 fighter jets often "provided themselves with" new restrictions on the flight modes. In recent months, before installing the new valves Raptor aircraft pilots had to fly at low altitudes, without costumes Combat Eagle. In addition, the command gave the order to pave the route to be flown in such a way, that at least some of its points can be reached before the coming airport in less than half an hour. It is easy to guess, as fell the combat potential of the new South American fighter. But the cause of all these technical problems, accidents and health problems of the pilots was a small valve, which at one time somehow managed to pass all the checks and tests.
Impact strength and weakness of the shock
The program ATF during initial concept development included the creation of a promising fighter-bomber. The plane was due to similar efficacy to destroy both air and ground targets. But in the process of elaboration of the technical characteristics of the aircraft of the future, a number of problems. First, problems adding a concept of balance. Requirements stealth led to the placement of weapons inside the fuselage, which, in turn, has forced designers to shrink very gruzootsekah. As a result of this most of the South American guided missile "air-to-ground" simply can not fit inside the volume allocated for the F-22 under the arms. For example, anti-radiation missile AGM-88 HARM by about half a meter longer than the AIM-120 missiles and has almost three times as large wingspan. In addition, HARM 200 pounds heavier missiles AMRAAM. So Makar, weight and dimensions of the main modern anti-radar missiles the U.S. do not allow to run it with the F-22. Naturally, the "Raptor" can carry a rocket and on the outside of the suspension, but in this case, from the modest hunter radars it is converted to another particularly terrible goal, which will be enticed to discover special attention to enemy air defenses. As for bombs, it is the case with them about the same as the missile. Load capacity of internal suspension prevents the aircraft to take on board large and languorous ammunition. Caliber used bombs limited tyschey pounds (454 kg).
Noticeable feature of the avionics the F-22 is a complete absence of any special equipment designed only for use against ground targets. The requirement to enter the price of the aircraft in a certain amount of the Pentagon, even to the detriment of features, resulted in elimination of its kind Bomber appropriate equipment. With all of this company's engineers "Lockheed Martin" tried to keep at least a limited capacity for bombing. In software, on-board computers shrewdly left methods needed for the detection and identification of ground targets. The defeat of these goals, in turn, from the very beginning it was intended to produce controlled-guided bombs on a signal navigation system GPS. After adopting a set of JDAM, created for the conversion svobodnopadayuschih bombs in controlled configuration, specifically these "smart" munitions have become the main tool of F-22s to attack ground targets.
Availability of GPS-corrected bombs in the arsenal of the F-22 is palpable expanded his fighting ability. But not too far because I would like the customer. In practice, one Raptor can carry primarily gruzootseke only two bombs GBU-32 JDAM caliber on tysche pounds. Once with 2 bombs aircraft have to take on board at the two missiles AMRAAM (mainly gruzootseke) and two Sidewinder in the side. The use of converted aircraft bombs forced to approach the target up close, because of what has to carry a weapon for self-defense. In autumn 2006, the Air Force of the United States was adopted by the correctable bomb GBU-39 SDB (Small Diameter Bomb — small diameter bomb). This 250-pound guided munition has a system similar to the bombs JDAM. Thanks to the smallest size and lowest weight, mainly gruzootseke F-22 can hold up to sixteen of these bombs. But in practice, will upload at least eight — the last holders of head gruzootsekah and additional "bomb doors" again are allocated to the guided missiles for self-defense. So Makarov, one aircraft can carry up to four GBU-39 bombs with a range of up to 110 kilometers an act. All the same, the number and range of offset power, because GBU-39 is only 17 kilograms of explosives against 202 kg in GBU-32.
In general, F-22 has excellent ability of air combat, for which he had at first intended, but all this can not hold vsepolnotsenno attack ground targets. Because of this, the U.S. Air Force strike force in cases where you need to storm the facilities or equipment of the enemy, continue to be for quite an old F-15s and F-16s later modifications. Practically speaking, difficulty with weapons "air-land" is one of the major reasons that the "Raptors" did not take part in conflicts near future. Ground attack is very difficult because of the small range of the respective arms. As gain advantages in the air, the ability of some modern conflicts F-22 may even be superfluous. For example, during the war in Iraq, South American F/A-18 fighter-bombers in the air battles killed about forty Iraqi aircraft. With all of this in similar clashes had lost only one South American fighter. Fully say that to deal with the air forces of the Third World F-22 is not very efficient in economic terms: the combat operation of the fighter costs noticeably more expensive than other types of crashes. Combat effectiveness with all this, taking into account the purposes of disposition, is approximately equal.
It should be noted that the fighter Lockheed Martin F-22 Raptor is even less technical problems, if economic. As already mentioned, the technology and the financial side of the project is very much linked together and constantly intersect. In terms of the ratio of technical advantages and prices creators of the project F-22 and failed to meet the required balance. Satisfaction of customer requirements has led to a constant need for additional research and development work. As a result, as part of the project there were new notable technical solutions that, but, provided the most direct impact
on the total price of all applets. As a result, some good features aircraft must own the highest price.
But despite all the know-how, "Raptor" ultimately received insufficient ability to attack ground targets. It says here the second time the general form in which it was not possible to observe want balance. Low visibility to radar has led to the requirement to fit the entire payload inside the fuselage, which directly impacted the very permissible dimensions of ammunition and, as a consequence, the range of weapons. With all of this avionics aircraft fully capable of working not only with bombs, suggestive of the alarm system GPS. But in view of the economic and technical challenges plane and failed to equip the equipment, such as bombs or guided missiles against laser. As for ammunition "air-to-ground" with a radar-guided, here his speech was delivered by a number of reasons. Suitable bombs or missiles with active radar seeker or were very bolshennymi and languid, or who are lacking power. The introduction of passive radar head, in turn, is connected with the need to target illumination, and it is almost completely eliminates all the advantages of the low-key design. So JDAM bombs and SDB almost a compromise between unobtrusive and least satisfactory shock abilities.
Summarizing, we can say that the technology side of the project F-22 to some extent, a justification for the higher price of the unique works and construction of the aircraft. Yet, some successful and promising solutions remain unclear for mass use. Fortunately for the U.S. military, all the problems are fixed uniformly fighter, although this leads to additional embezzlement or the need to impose restrictions on the modes of operation. But the project Raptor went so complex that it is difficult to predict how soon there will be new reports of technical dilemmas, and what specific aspects of the design, they will relate to. Nov. 15 near Tyndall Air Base (Florida, USA) crashed the next drill F-22. The investigation of the incident has been a special commission, and any information not yet disclosed. At the current time, no one can rule out the possibility that the recent tragedy will be the beginning of a whole string of events, as it was a two-year-old catastrophe. If this is indeed so, the F-22 fighter risks to secure for itself a reputation for not only the most expensive and controversial aircraft in the history of American aviation, but also the most complex and unpredictable in operation.
Kudishin IV F-22 "Raptor" and JSF. South American fighters fifth generation. — Moscow: AST / AST, 2002