Problems F-22 fighter Rapror. Part II: Arms and equipment

Problems F-22 fighter Rapror. Part II: Arms and equipment

In the first part of our article we spotted background high price of the new South American fighter Lockheed Martin F-22 Raptor. As it turns out, the program of creation of this aircraft, which looked at the time not itself too complicated, over time has acquired a mass of problems, which ultimately affected the price of research and development work, as the cost of building at least some of the aircraft taken separately. Fully understood that economic difficulties are associated with technical disposition neuvvyazkami. Development of new technologies, as correction on first glance, small imperfections may ultimately tangible increment the price of all applets. Consider the tech side of the project F-22 and understand what has been done and what is not. In addition, some features of attention are aircraft that have survived right up to the last parties of mass production.

Once again, you have to remind: the bulk of technical information about the Raptor fighter so far is closed and is only available to certain U.S. military personnel who have appropriate permission. For this reason, all the information below was taken only from open sources and may not be one hundred percent compliance is the real current situation. In addition, a number of technical problems or difficulties of the F-22 is directly linked to the monetary side of the project, because the second part of the article may overlap with and complement the first.

Problems F-22 fighter Rapror. Part II: Arms and equipment

Philosophy equilibrium

Since the mid 80s, the program ATF (Advanced Tactical Fighter — «Progressive tactical fighter») was carried out in accordance with the refreshed monetary ideology. Military began to seek not any properties at any cost, but very likely flight and combat characteristics, which can be achieved at a cost of 1st aircraft in 35-40 million dollars. At the time, such an approach has received a lot of positive reviews, but in practice it turned out even harder. In the light of new technical solutions form the future of the F-22 became known as balanced. First, it concerns the general equilibrium totality of features and prices. In a more specific embodiment of the concept of equilibrium sought without much harm to «make friends» at once a few features and technical aspects. So, good maneuverability needed to connect with a low visibility, low visibility, and her appropriate contour of the airplane with a decent fuel supplies and weapons, etc.. Overall, good-looking and fascinating ideology balance different features of threatened mass problems for engineers. Pentagon sought as before very likely properties to ensure that it was sometimes very hard.

And yet the designers office «Lockheed Martin» managed to partly satisfy the demands of the military, also give the aircraft a maximum capacity that could provide the data within the weight and size and money. First, let the brakes on stealth. According to reports, the fighter F-22 has an effective area of ​​scattering at 0.3-0.4 per square meter. Unlike frankly bad F-117A, F-22 fighter was placed first as a fighting machine with decent flight data. Stealth received the least value, causing the plane was ready special fuselage and wings which, at the same time, do not have significant differences from most fighters. Anyway, in its general form «Raptor» really looks like a plane, not a weird iron, as it was with the F-117A. Low profile, in turn, is achieved by means of secondary importance, such as the monotonous orientation edges are at an angle to the longitudinal axis of the aircraft or the collapsed outside keels. In developing such kind of aerodynamic staff offices Lockheed and NASA had to seriously face the «equilibrium.» 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 must be super-maneuverable, which is usually achieved by using engines with thrust vector control. On the F-22 used unique rectangular nozzle flaps deflected. Immediately to the configuration of the thrust vector nozzles provide such effective temperature drop throws gas. As a consequence, came to achieve a reasonable balance between maneuverability and visibility in the infrared spectrum. Employees of companies Lockheed Martin and Pratt & Whitney could make the power plant, which completely meets 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 during the entire first phase of the project, related to the definition of common features of the future aircraft. The need for balance between the flight data and discreet led to the application of a number of diverse technical solutions. For example, originally supposed to do the power set of composite wing only on the basis of carbon fiber parts. 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 difficult to manufacture and are not applicable for almost frisky substitution criteria in military workshop. Needless to say, the change of the parts of the power set entailed severe alteration of all related components and assemblies, also complicate the creation of tangible frame of the aircraft.

Problems F-22 fighter Rapror. Part II: Arms and equipment

All I carry within themselves …

Relevant feature of the F-22 was the lack of constant external suspensions created for use in battle. Under the wing of a fighter as required can be set to four pylons mounted fuel tanks or missile. But in this case the EPR characteristics of the aircraft significantly grow and display radar, it looks about the same as a old F-15 or F-16. Because of this, in a real combat situation it is recommended to use only the internal suspension.

Implementing only the internal volumes, coupled with the required dimensions and masses promising aircraft was one of the most challenging goals in its development. If the internal tanks everything was more or less just and under their given virtually all available volumes, the transportation and the use of weapons had to tinker. In 1-x, it is necessary to allocate amounts under gruzootsekah. The main volume of the weapons placed in the middle of the fuselage, immediately behind vozduhopoglotitelyami. The dimensions and equipment of gruzootsekah permit to locate it to 6 AIM-120 missiles. Another two smallest volume placed on the edges of the core. In each of them there is room for only one AIM-9 missiles. Second problem when developing gruzootsekah was to safeguard the use of weapons in all criteria. Needed a device that can push the boundaries of a rocket the internal volume of the aircraft when flying at tremendous speeds and at least some overload.

In light of the technical data of different types of missiles had to be done immediately launch two devices. For more languid and large AIM-120 developed ejection device capable missile thrown from the aircraft at supersonic speeds and across the spectrum of permissible overloads. This unit is a system of pneumatic and hydraulic cylinders. First at a speed of about eight meters per second outputs rocket abroad gruzootsekah, «punching» the boundary layer of air. Second, in turn, provides a cutaway of the munition, and its withdrawal from the side plane. The already complex system ejection gun was complicated by the fact that in a combat situation requires a little time, extending from pressing the start button to start a solo flight of the rocket. 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. Military first want to get more frisky device, but subsequent work in this direction have been stopped because of the strength characteristics of missiles. AIM-120 comes with an overload of gruzootsekah about forty units. Greater acceleration when released can cause damage to the ammunition directly to the full its inoperability.

Second missile ejection system created for lighter AIM-9 and is built on a different principle. Before launching the rocket descends from gruzootsekah, the front part pushed harder than the back. Trapezoidal unit that hosts the restraints do not have any means for shooting rockets — after switching on the motor, it goes without help from the guide. Indoor units are protected by a special aircraft gaz baffling guard. Completely understandable that both options launchers even harder than usual underwing pylons beamed holders. Moreover, this applies to the complexity of construction, and maintenance. From of old structures and ejector trapezoid do not differ only «attitude» to the pilot. Him as before quite easily push button befitting. Relevant feature of the new complex machines proved the impossibility of their failure. Requirements for stealth just do not give to simplify the design and service of aircraft by use of the least complicated firing mechanisms.

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 compounded EPR aircraft are also likely some problem with the aerodynamics. In the late 90’s pylons for drop tanks or weapons already undergone severe processing. During testing, it became clear 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 design. When developing new attachments engineers «Lockheed Martin» tried to provide the lowest visibility of the aircraft even when using pylons. To this end, according to some sources, they are in the form of whole carbon fiber parts. Given the fact that the pylons can be discharged to ensure vsepolnotsennyh piloting skills and stealth, this design does not look particularly successful at first, in financial terms. During the following upgrades planned to return to this subject again and improve pylons for external suspension.

Problems F-22 fighter Rapror. Part II: Arms and equipment

Hard to be independent

One of the main requirements for the brand new aircraft was to simplify maintenance and preparation for departure. For this purpose, in order to accelerate the start-board systems, F-22, equipped with an auxiliary power unit. This unit provides electricity to start plane engines that drive the main generators, hydraulic and pneumatic pumps. It should be noted, MAT fighter was one of the most trusted sites. Last big problems with an auxiliary power unit finished in the late 90s, 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 maintenance support system to become a pilot, and specifically its part, is responsible for the supply of air and oxygen. On all American aircraft to the F-22 pilot receives oxygen for respiration of the respective cylinders. But such a system asks unchanged refueling or substitution of domestic gas tanks. Since the F-22 had to be able to patrol the long and very frolicsome 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 — Onboard generation of oxygen). 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 regenerating tapes and cleaning the filters. As a substitute of the respiratory system on the F-22 units installed additional complex EOS «classical» standard: oxygen tank and related equipment.

Excluding specific software pilot oxygen system OBOGS responsible for protecting the pilot from overloads. The structure of the life support systems combined comes suit Combat Eagle, uniting in itself anti-g, altitude-compensating and heat-shielding characteristics. Pretty difficult construction of a suit in the middle of the rest, led to his inability to conduct repairs in the criteria of the drill. Because the determination of damage suit Combat Eagle simply written off and the pilot receives new. But, as it turns out, a small anti-G suits and maintainability complexity of the regeneration system was not far greatest neuvvyazkami new fighter. A few months back the clock, it became clear that a lot of problems in life support pilot brought one small detail, which is first, no one thought in something incriminating.

Problems F-22 fighter Rapror. Part II: Arms and equipment

Choking overload

Middle of November 2010 drill in Alaska crashed F-22 fighter pilot J. Haney died. Prerequisite accident recognized system failure OBOGS, caused by hypoxia, due to which the pilot lost consciousness and had no time to spare to include EOS. Because of this, all aircraft updated software — now including spare respiratory system is automatic. But these alterations are not one hundred percent guaranteed to get rid of problems. In the upcoming pilots combat units more than once complained severe problem in flight: in some cases they felt all sorts of strangulation. After the regular commission proceedings and the U.S. Air Force Lockheed Martin learned that suffocation is a prerequisite synchronism respiratory system module OBOGS, responsible for pilot oxygen supply pressure, and units, looking for compensation overloads. Dissynchronization of these parts of the complex life support chest and tummy pinched pilot suit on the outside and inside pressure is not compensated enough pressure 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 short strangulation reports filed with the request to remove them from flying on the F-22 to fix all the problems.

In July 2012 the Pentagon said the official dealer of the investigation results. It turned out that the dilemmas with strangulation was povinet system module OBOGS, was responsible for the proper functioning of the anti-G a suit Combat Eagle. Specifically, not the module, and one of its parts. One of the valves of the pumping of 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 overdrive module OBOGS reduced oxygen supply pressure to the desired value, and the suit continued to be inflated to the time until the air bleed out of it with such a pace, which could ensure that fateful valve. Even before the announcement of the results of the investigation in the air supply system antigravity was visibly refined and tested again for proper operation. By the end of this summer, was created a set of new items created for retrofitting combat aircraft 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 tasks are part of a complex with an antigravity OBOGS entailed not only a health problem pilots. Starting with the crash of 2010, the F-22 fighter jets often «acquire their» new restrictions on the flight modes. In recent months, before installing the new valves Raptor aircraft pilots had to fly at low altitudes and without costumes Combat Eagle. In addition, the command had ordered a route of flight 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 pilots was a small valve, which at one time somehow managed to pass all the checks and tests.

Problems F-22 fighter Rapror. Part II: Arms and equipment

Impact strength and weakness 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 features of the future aircraft, a number of problems. First, problems added a concept of equilibrium. Stealth requirements led to the placement of all weapons inside the fuselage, which, in turn, has led designers to shrink very gruzootsekah. As a result of this most of the South American guided weapons «air-land» simply can not fit inside the volume allotted 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 larger wingspan. In addition, HARM 200 pounds heavier missiles AMRAAM. So Makar, weight and dimensions of the main modern anti-radar missiles the U.S. does not allow you to run it with the F-22. Naturally, the «Raptor» may bear on the outside of the rocket and suspension, but in this case of flea hunter radars it is converted to another particularly terrible goal that enticed to discover special attention of enemy air defenses. As for bombs, then with them the situation is about the same as with missiles. Payload internal suspension does not allow aircraft to take on board large and languorous ammunition. Caliber used bombs limited tyschey pounds (454 kg).

Noticeable feature of the avionics of 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, entailed the elimination of its kind Bomber appropriate equipment. With all this, engineers office «Lockheed Martin» tried to keep at least a limited ability Bombing. The software onboard computers shrewdly left methods needed for detection and identification of ground targets. Defeat these goals, in turn, from the outset intended to produce controlled bombs with guidance signal navigation system GPS. After adopting a set of JDAM, created by conversion svobodnopadayuschih bombs in controlled configuration, specifically such «smart» munitions have become the main instrument of the F-22 to attack ground targets.

Availability of GPS-corrected bombs in the arsenal of the F-22 is palpable expanded its combat abilities. But not too far because it would be desirable to the customer. In practice, one can carry Raptor gruzootseke basically only two bombs GBU-32 JDAM caliber on tysche pounds. Once with 2 bombs aircraft have to take on board two missiles AMRAAM (mainly gruzootseke) and two Sidewinder in the side. Application refitted aircraft bombs forces approached the target is quite close, because of what has to carry a weapon for self-defense. In autumn 2006, USAF has adopted an correctable bomb GBU-39 SDB (Small Diameter Bomb — Bomb small diameter). This 250-pound warhead has a guidance system similar bombs JDAM. Thanks to the smallest size and lowest weight, mainly gruzootseke F-22 can hold up to sixteen such bombs. But in practice, will get at least eight — the last head gruzootsekah holders and additional «bomb doors» again discharged under guided missiles for self-defense. So Makarov, one aircraft can carry up to 4 bombs GBU-39 with a radius of up to 110 km acts. Yet, the number and range of offset power, because GBU-39 carries a total of 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 vsepolnotsenno conduct ground attack. Because of this, the U.S. Air Force strike force in cases where you need to storm the enemy objects or vehicles continue to be already quite old F-15s and F-16s later modifications. Practically speaking, difficulty with weapons «air-land» is one of the main reasons that the «Raptors» is not perceived as a conflict shortly. Ground attack hampered by the very small range of the respective arms. As regards the air gains advantages, the ability of some modern conflicts F-22 may even be superfluous. Thus, during the war in Iraq South American F/A-18 fighter-bombers in the air battles killed about forty Iraqi aircraft. With all this in similar clashes had lost only one South American fighter. Fully understood that to fight with the air forces of the Third World F-22 is not very efficient in economic terms: combat work of the fighter costs noticeably more expensive than other types of crashes. Combat effectiveness with all this, taking into account the purposes of disposition, out of approximately equal.
Diverse outcome

It should be noted that the fighter Lockheed Martin F-22 Raptor has more than technical problems, if economic. As already mentioned, techno and financial aspects of the project are very very tied 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 consequence, part of the project appeared noteworthy new technical solutions, but, provided the most direct impact on the overall price of all applets. As a result, decent features aircraft must own the highest price.

But despite all the know-how, «Raptor» eventually received insufficient ability to attack ground targets. It says here the second point of the generic type which have failed to comply with the balance we want. Low visibility to radar led to the requirement to get all the payload inside the fuselage, which directly impacted the very permissible dimensions and ammunition, as a consequence, the range of weapons. With all of this avionics aircraft fully capable of working not only with bombs, suggestive signal system GPS. But due to economic and technical problems plane and failed to equip the equipment, such as bombs or missiles pointing at the laser. As for ammunition «air-ground» with a radar-guided, then there is his word uttered a number of reasons. Suitable bombs or missiles with active radar seeker or were very languid and bolshennymi, owning or lacking power. Implementation of passive radar head, in turn, is connected with the necessity of target illumination, and it is almost completely eliminates all the advantages of unobtrusive design. So bombs JDAM and SDB almost a compromise between unobtrusive and at least satisfactory shock abilities.

Summarizing, we can say that the techno side project F-22 in some measure is the justification for the higher price of 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 flight modes. 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 aspect of the design, they will touch. November 15 close to the airbase Tindall (Florida, USA) crashed another F-22 drill. Investigation of the incident has been a special commission, and any information not yet disclosed. Currently, one can not exclude the possibility that the recent tragedy will be the start for a whole string of events, as it was with a two-year-old catastrophe. If this is indeed so, the F-22 fighter risks perpetuating its reputation as not only the most expensive and controversial aircraft in the history of American aviation, but also the most complex and unpredictable in operation.


source topwar.ru

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