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- ray ban11
- Legendarni građanin
- Pridružio: 17 Sep 2010
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Jedan zanimljiv clanak koji nije samo puka kopija raznih `deja vu` izdanja ,ima tu nekih sitnica manje vise koje su opste poznate malo tacnosti i malo netacnosti medjutim posebno je interesantan citat izjave jednog od pilota .
Citat:
The MiG-31 Foxhound exhibited for the first time at the Paris 1991 Airshow entered production in 1979 and, with a speed of Mach 2.35, now assumes the title of the fastest production military aircraft in the world following the retirement of the Lockheed SR-71. Sitting on its large staggered twin-wheel main undercarriage, the 70 ft 6 in (21.5 m) long MiG-31 is a mighty machine.
Fitted with a Zaslon phased array radar, the Soviets surprised everyone by removing the nose cone for the world to see the antenna which is reportedly capable of tracking ten targets and attacking four simultaneously. The engines are Soloviev D-30F-6 two-shaft bypass turbojets, each with a reheat thrust of 152 kN. The Soviets made a surprising move, showing for the first time the AA-9 Amos long range AAM. In addition to these four underfuselage weapons, two AA-6 Acrid AAMs were also shown for the first time; this missile has not previously been generally associated with the MiG-31, the wing pylons normally carrying twin AA-8 Aphid short-range AAMs. Fixed armament was confirmed to be a single 23 mm six-barrel GSh-23 rotary cannon with 260 rounds in a bulged housing behind the starboard main undercarriage. The aircraft has a fully-loaded take-off weight of 90,388 lb (41,000 kg) and a ferry range of 1,839 miles (3,000 km).
Zaslon Phased Array Radar The key to the MiG-31's effectiveness lies in its weapons system, which is probably the most effective ever fitted to a Soviet fighter aircraft. The heart of the system is the SBI-16 Zaslon radar, codenamed 'Flash Dance' by NATO. This is said to be the world's most powerful fighter radar, with a higher output in kilowatts than any other radar. When a MiG- 31 visited the 1991 Paris air salon, the radome was removed in the static aircraft park (much to everybody's surprise), revealing the radar's fixed, phased array antenna, believed to have been the first such antenna in a fighter. The radar's designers (the Research Institute of Equipment Design) describe such small phase array radars as Arrowhead' radars, this being a partial acronym (Arrays Of High Efficiency And Directivity) and claim a number of advantages. Since the antenna cannot move, the radar beam is 'pointed' electronically. The fixed antenna allows the full fuselage diameter to be used for the antenna, with no space for movement. This is significant since antenna diameter and effective operating range are directly related. The fixed antenna allows the radar beam to be steered faster and more accurately than with a conventional moving antenna and allows 'controlled beamshaping'. The radar designers also claim that fewer sidelobes are generated (and that such sidelobes as are generated can be better controlled). They also claim that reliability and radar gain can be maximized while minimizing weight complexity. Mikoyan claims that the antenna also allows rear hemisphere coverage, through 120 degrees on each side of the centerline. This is remarkable, since even with no rearward facing capability, the proximity of the radar emitters to the pilot would seem potentially hazardous. The only other operational phased array electronically steered antenna is that of the APQ-164 radar of the B-IB. Tired of accusations of copying Western technology, Soviet designers are eager to point out that their radar was in service two years before that of the B-IB. The radome of the MiG-31 at Paris was covered by thin muslin, which obscured some details. Waveguides were loot visible, but there did appear to be 24 horizontal rows of metallic emitters. Small dipoles spread across the face of the radome are probably for IFF or constant wave illumination for a semi-active radar-homing missile. It is uncertain as to what waveband is used, although Yuri Guskov, chief designer at Phazatron, has stated that the radar operates at "slightly lower than S- band" which corresponds to NATO's D-band. This raises more questions than it answers, since some Western analysts suggest that such a waveband would give a wide beam and inadequate resolution at long range. I- or G-bands are felt by some to be more likely, and Aviation Week stated that the radar operated in the mid l-band (9-9.5 GHz). All signal processing is digital. The radar allows the simultaneous tracking of 10 targets, and the simultaneous engagement of four targets. The aircraft's BTsVM(S) mission computer automatically selects the four most threatening targets for engagement. Radar performance IS Impressive, with a detection range (for a target with 16 m2 (172 sq ft) cross-section) of 200 km (124 miles) and a tracking range of 120km (74 miles). The phased array antenna allows the beam to sweep through 120 degrees in azimuth and from 70 degrees above the nose to 60 degrees below. The Russians claim that this allows the MiG-31 to engage targets spread over a greater area than can its Western equivalent, the F-14, although the Western aircraft call simultaneously engage a greater number of targets Mikoyan claims that the MiG-31 radar is capable of engaging missiles, and have referred to the aircraft as being like a patriot missile which can fly 'repeated missions'. They also claim to be testing the weapons system against 'Stealth' aircraft. The radar also has navigation and situation monitoring functions although navigation is more routinely handled by Marshroot (Soviet equivalent to Omega) and Tropik (Soviet equivalent to LORAN) systems, which give a accuracy of 250 m (820 ft) at a range of 2000 km (1,243 miles). The MiG-31 was designed to operate in those areas where there is no ground-based radar coverage, such as the north, using its sophisticated onboard systems for autonomous operations MiG-31s are most often used in group of four (or even eight), linked together by datalink. Operating together, four MiG-31s can cover a strip of territory 900 km (560 miles) across, and targets can be transferred rapidly from one aircraft to another, with all aircraft sharing the same image on their tactical situation displays. The transmission of target information between aircraft by datalink reduces the vulnerability to hostile jamming, while the radar's, angular tracking circuits are hard to deceive. Information denied by hostile jamming can be recovered using kinematic and triangulation methods. The aircraft is provided with secure digital datalinks to the ground (AK-RLDN) and between aircraft (APD-518). Conformal antennas for these are located respectively in the leading edges of the ventral fins and on the sides of the nose (three per side) and rear fuselage (two). The aircraft's datalinks and powerful radar also allow the MiG-31 to act as a 'mini AWACS' in its own right, directing and controlling other fighters. The lead navigator in a flight of four MiG-31s can even directly steer his wingmen's aircraft, since their autopilots can receive his commands via datalink. Radar is not, however, the MiG-31's only target acquisition and tracking sensor. To provide an emission-free alternative to radar, or to be used in the event of radar failure, the MiG-31 is equipped with a retractable undernose IRST
MiG-31 Powerplant From Perm The Soloviev D-30F6 was designed at Perm by a team led by Soloviev himself and since 1989 by Yuri Reshetnikov) with development beginning in 1972. The team was formed by two companies, Aviadvigatel and Motorostroitel. Development was finally completed in 1980. The engine is manufactured at Perm's Motorstroitel works, and is claimed to be a derivative of the same D-30 engine that is used to power the Ilyushin Il- 62M and Tupolev Tu-154M. The bypass turbofan gives an excellent specific fuel consumption in the cruise, while the bypass flow around the engine's inner core reduces thermal stresses on the engine. In this context, the 5 kg (11 lb) of silver used to give a reflective coating to MiG-25 engine bay heat shields has been dispensed with on the MiG-31. One unique feature of the D-30F6 is the use of small suction relief doors on the moving parts of the engine nozzles to eliminate pulsing in the exhaust gases. The engine consists of seven modules, six of them replaceable. The first is an inlet guide vane module, with the others being the five-stage low pressure compressor, the mixer case, the afterburner, the exhaust nozzle, front and rear gearboxes, and a base module with the 10-stage high pressure compressor and combustion chamber, first stage nozzle vanes, high and low pressure turbines (both two stage) and rear bearing. The engine has a mass flow of 150kg (330 lb) per second and an inlet diameter of 102 cm (40 in). The D-30F6 features an integral heat exchanger using fan bypass air to cool air drawn from the compressor which in turn cools the high- and low-pressure turbines. A turbine overspend protection system is fitted, along with an exhaust temperature limiter. Full authority digital engine controls are fitted, with a data recording system. The new engine was specified for the MiG-31 in order to improve range, since this was the key performance parameter for which an improvement over the MiG-25 was demanded. The new powerplant necessitated some structural modifications, and the opportunity was taken to increase internal fuel capacity to 19700 liters (4,333 Imp gal) (some estimates suggest 20380 liters/4,483 Imp gal). This, together with the lower specific fuel consumption of the D-30F, raised supersonic range to 2135 km (1,327 miles) on internal fuel, or to 3310 km (2,057 miles) at subsonic speeds. Increased weight reduced operational ceiling to 21900 m (71,850 ft).
MiG-31 Pilot's Viewpoints "For me, with quite an experience level in the MiG-25P/PD, the MiG-31 seemed a new aircraft. Firstly it was a tandem two seat, the new weapons systems made necessary that a navigator-radar officer should be installed in the rear cockpit. The airbrakes were fitted in a new position, between the main landing gear and the air intakes. The main landing gear was substantially modified, each leg being fitted with two wheels ingeniously offset in order to operate effectively from snowed, iced and non-prepared surfaces. Ailerons and flaps occupied the entire wing trailing edge. "Some of the test flights associated with its operational capabilities in which I did participate, comprised missions over the far north of the then Soviet Union, evaluating the new navigation system in an area where important magnetic anomalies take place. Some very long- range missions to the Union's Far East took place (with the aid of air-to- air refueling); even the North Pole was overflown. Thanks to these and previous tests the MiG-31 incorporated new maneuvering flaps along the full span of the wing's leading edge, comprising four sections for each half wing. Another novelty was the leading edge extension and as it had lowlevel supersonic capability the wing structure was reinforced with the addition of a third spar. A semi-retractable refueling probe was fitted on the left side of the nose. "The MiG-31 operational capabilities are intimately associated to its new weapons system which comprise three main elements: a ZBI-16 Zaslon phased array radar (the first and the only so far fitted to a fighter) with excellent lookdown capability; a retractable IRST system fitted under the front fuselage; and a tactical situation display in the rear cockpit The radar's range in acquisition-pursuit in lookdown is 150-200 km in the forward sector and 70-90 for the rear sector. Ten hostile contacts can be tracked at the same time, of which four can be engaged at the same time. The simultaneous pursuit-shooting angle is 70 degrees in azimuth and 60-75 degrees in elevation. As in a fighter of these characteristics, navigation was of paramount importance and redundant systems were fitted, a Tropik LORAN and a Marchroot Omega.
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