Aerospace |
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The Knight
Of The 21st Century Nowadays, many nations are faced with a similar dilemma: How can one reduce a military budget without lowering the defense capability below a critical level? The Sukhoi design bureau offers an option of reaching "disarmament via re-armament." In practice, this formula calls for replacement of huge arsenals of outdated weapons with relatively small number of new-generation multi-role aircraft with the ability to fulfill the same tasks at considerably lower costs. Vladimir Babak, director of the Sukhoi Attack Aircraft division, says that replacement of aging tactical aircraft with newest Su-39s would allow a reduction in the number of air squadrons two to three times without sacrificing the overall combat capability. Subsequently, the number of servicemen can be cut several times, as well as the budgetary expenses allocated for defense needs. According to Babak, the major goal for the defender in the first phases of war is to defeat, or, at least, to stop the advancing armor units of the aggressor in order to allow the Land Forces time to re-group and strike back. The Su-39 attack aircraft is specially designed for solving this task within a 800-900 km radius. History The idea of using aviation against tanks is not new. Back in the 1970s, the US and USSR created the A-10 and Su-25 armored attack aircraft. They did well in many conflicts, including those in Afghanistan, Persian Gulf, Chechnya and others. At first, the second advent of the "flying tanks," whichtook place during the era of supersonic flights, was met with skepticism from military leaders. In many cases, these negative attitudes changed after seeing the planes in action. A gentleman from Sukhoi visited Iraq shortly after Desert Storm to demonstrate results of Su-25 sorties against the advancing Coalition forces. According to Sukhoi , in the last days of war, the Iraqis defeated several forward enemy units, which made the US stop the hostilities. In this operation, about 40 Su-25s participated. It may well be a fairly tale, but the improbability of the story gets lower and lower each time as more and more former secret US documents on the war become public. Time, however, took its toll, and both the A-10 and Su-25 became outdated. Both types cannot fulfill new tasks on the battlefield, like that on reliable destruction of highly-mobile compact targets at night and in the conditions of low clouds. This exact task was in the minds of Sukhoi designers working on the Su-39. Tasks For Su-39 The Su-39 was born as a thorough modification of the Su-25. At the first stages of its development, the machine carried designation Su-25T, and then Su-25TK and TM. Letter "T" was for "(anti-)tank", "K" for "commercial" (export), "M" for "modified." From the ordinary Su-25, the new versions differed in having a "hunch" on the fuselage just after the cockpit and a TV sight with a magnification of 23 in the nose. Two R-195Sh engines, 10 percent more powerful then its predecessors, have compensated for a two-ton increase in the gross take-off weight. The first Su-25T built took flight in 1984. Since then, the design has moved farther away from the initial Su- 25. Here are the three major tasks for the Su-39 as formulated by the Sukhoi design bureau: - to destroy tanks, infantry fighting vehicles, armored personnel carriers and self-propelled guns on the battlefield, on the march and places of concentration in all weathers by day and night; - to engage sea targets, including torpedo and missile boats, landing ships, frigates and destroyers; -- to destroy helicopters, strike and transport airplanes in the air and on the ground. The process of performing ground attack missions by the Su-39 is maximally automated. As a result, the workload on the Su-39 pilot is relatively low, which helps him fulfill combat tasks. A positive influence on the pilot is produced by good armor protection - the Su- 39's cockpit is a titanium-welded construction, which sustains shells up to 30 mm. Scenario A typical scenario of a sortie against a ground target was presented by Sukhoi people working on the program. The way and approach to the target are carried out automatically, based on the data loaded into the on-board complex before the take-off. Current coordinates of the plane are determined, with an error of 10-15 m, by a global-positioning system using data from GLONASS and NAVSTAR satellites. The coordinates are determined by an inertial navigation system and corrected by an optical seeker and radar. Upon entering the approach phase, the Shkval on-board electro-optical complex starts functioning at a mapping mode. Depending on altitude, the Shkval scans area within a certain width. Having spotted the target on the TV screen, the pilot stops scanning, frames the area and puts cross- heads on the target. From that moment, the target is tracked by the TV camera while the flight management system automatically directs the aircraft onto the target. In the case of a bombing run, the pilot keeps the fire button depressed until a bomb is automatically released under command from the aiming system. In the case of guided weapons, the pilot launches a missile by pressing the fire bottom and watches the results of fire on the TV screen. To repeat the attack or to leave the area the pilot presses an appropriate button. To fulfill the same mission at night, the Su-39 has the Mercury low-level TV system in the under-wing pod. The scenario remains the same, except that the picture on the screen is formed by the Mercury instead of the Shkval. At one time, Sukhoi performed extensive experiments with heat sensors, which proved them unsuitable for combat aircraft due to poor reliability and bad target-identification in the European conditions. It is worth noting that contrary to their western colleagues, who largely employ heat systems for navigation, Sukhoi specialists intended to make use of forward-looking infra-red sensors as a part in the Su-39 aiming complex. Babak says that after a series of failures with Russian systems, he lost all hopes of finding a good FLIR for the Su-39 after getting acquainted with western heat sensors. According to him, another 10 years of development is needed to make FLIRs reliable for work with precise weapons. Radar Benefits The Su-39 differs from the fight-generation armored jets in having a multifunctional radar. Developed by Phazatron company, the Kopyo is a coherent-pulse X-band Doppler radar operating in air-to-air and air-to- surface modes. In case of a ground-attack mission, the radar provides all-weather round-the-clock capability and preliminary target-acquisition function. The Kopyo can detect a tank column moving along a road in a wooden area at a distance of 20 km. In the case of a railway bridge the distance may be as long as 100 km. Among the weapons systems working in conjunction with the radar are R27T, R27R, RVV-AEE air-to-air and X-31A anti-ship missiles. With RV- AEE beyond-vision-range missiles under its wings, the attack aircraft is on the par with an interceptor carrying AIM-7s and AIM-120s. The Su-39 is not a less dangerous enemy in dog-fight. The R-73E self-defense missile is considered the world's best in its class, whereas a powerful electro-optical jammer built in the tail effectively distracts the Super Sidewinder's seeker. To shoot down the Sukhoi, it is necessary to score at least 30 hits with 20-mm shells of the Vulcan cannon. It is not easy to achieve such a success, because at low altitudes the Su-39 has a shorter turn radius than any of the existing fighters. The Su-39 also carries the SRTR radar-warning system, providing the pilot with complete information on working ground and airborne radars. The system does not merely warn the pilot - it also allows them to use the X- 31P and X-58UE anti-radar missiles against stationary threats. Alternatively, the Su-39 can attack hostile radars with the X-25ML and Vikhr laser-guided missiles. Vikhr The laser-beam-riding Vikhr missile is intended primarily for engaging modern tanks with so-called active armor. Its warhead is able to pierce a 1,000-mm steel shield. Vladimir Babak says the likelihood of scoring a direct hit against a moving Leopard-2 tank with one Vikhr missile lies between 0.8 and 0.85. The Su-39 can destroy enemy tanks with the Vikhr at a distance of 8 km, remaining out of reach for the self-propelled SAMs that follow behind the advancing armored vehicles. In addition, a relatively short minimum firing distance of 1,200 m makes it possible to use the Vikhr in limited visibility conditions. Europe is often covered with low-height clouds, making aircraft armed with X-25ML or Maverick missiles hard to hit moving tanks. Vladimir Babak says that the combination of the Shkval and Vikhr has allowed Sukhoi to surpass foreigners in the technologies of performing aerial strikes. Guided weapons are very expensive because most have highly-sensitive sensors and computers as parts in their homing systems. But the Vikhr is different. On the way to the target it follows the laser beam, emitted by the designator system on the aircraft. The Vikhr has laser-beam receivers in its rear part, generating signals on the control surfaces until the impact. This technology does have its disadvantages. For one, target-illumination should be provided the whole time the missile flies. To shorten the time, Vikhr is made supersonic. In 1993, Sukhoi completed trials on eight Su-25Ts, during which 3,000 flights were made and 40 Vikhrs were fired. According to Babak, the hit ratio was almost 100 percent. Babak says that in one pass, Su-25T pilots routinely hit two targets, sometimes even three. The inclusion of Vikhr missiles into the Su-39 arsenal has made the aircraft a truly universal combat vehicle. Supersonic speed, high accuracy and relatively long range allow the missile to be effective against various aerial, ground and sea targets. Fully-laden, the Su-39 carries 16 Vikhrs and, in favorable circumstances, can destroy up to 12 tanks and helicopters in one sortie. Nose changes So far, three examples of the Su-39 have been built, including one at
Sukhoi pilot plant in Moscow and two at the mass production factory in Ulan-Ude.
It is planned to assemble six more Su-39 prototypes for assessment trials
in military units. Now Sukhoi specialists are finishing work on integration
of the Kopyo radar and associated weapons with the new weapons management
complex. After the job is done, the radar will be moved from the under fuselage
pod into the nose. Subsequently, the Shkval will be moved under the nose
section. Other changes will include replacement of some dial instrumentation
with a second multi-functional display. Sukhoi hopes to sell the Su-39 to
small countries as a universal combat aircraft able to fulfill close air
support, interdiction, air-defense and anti-ship roles. Babak says that
the Su-25T is also available for budget-restricted clients (it lacks the
radar and, therefore, costs less.) The Su-39 production is being set at
the factory in Ulan-Ude, while the Su-25 assembly line is in Tbilisi, Georgia.
Vladimir Babak claims that a comparative analysis undertaken by Sukhoi design
bureau and Russian military and scientific establishments have revealed
the benefits of the Su-39 over the F-16C, Mirage- 2000-5, Rafale and Grippen
in fulfilling 12 combat missions typically flown by close air support units.
Based on this analysis, Sukhoi is marketing the Su-39 as the world's best
value-for-money close-support aircraft able to keep national defense at
a reasonably high level. |
