The rocket of the American portable anti-aircraft complex FIM-92 Stinger was so successful that it was chosen for use on self-propelled air defense systems. This is how the AN / TWQ-1 Avenger complexes appeared based on the HMMWV car, the M6 Linebacker on the M2 Bradley BMP chassis and a number of other interesting systems. This approach to the creation of short-range air defense systems justified itself and soon attracted the interest of other countries. Among them was China, which started a similar project called Yitian in the late nineties.
The new Chinese air defense system Yitian, developed by NORINCO, is designed to accompany troops on the march and to defend stationary objects. In fact, the complex is a combat module with electronic equipment and weapons, which, after minor changes, can be installed on any suitable chassis. So, at the international exhibition IDEX-2009, two versions of a self-propelled missile system were demonstrated: based on the Type 92A armored personnel carrier (another designation is WZ 551) and on the EQ2050 chassis. In addition, it is known about the existence of a towed version of the launcher designed for use with other anti-aircraft weapons. For convenience, as an example of a Yitian combat vehicle, we will first consider an armored vehicle-based option.
The six-wheeled combat vehicle is equipped with a 320 horsepower diesel engine, which allows it to accelerate on the highway to speeds of about 80-85 kilometers per hour. If necessary, a self-propelled air defense system can swim across water obstacles, but its ability to navigate is significantly limited by a large and heavy combat module on the roof. Rolled steel armor protects the crew and chassis assemblies from small arms bullets and shrapnel. The combat weight of the vehicle based on the Type 92A armored personnel carrier is about 16 tons. For self-defense, it is equipped with one W85 heavy machine gun and smoke grenade launchers. During the construction of a self-propelled anti-aircraft complex in the middle part of the roof, in place of the native tower, a new combat module with equipment and a launcher is installed.
Externally, the combat module is a swivel tower, on the sides of which there are launchers with transport and launch containers (TPK) of missiles. In the middle part of the tower there is a block of optoelectronic equipment, and on the roof there is an antenna of a target detection radar station. The antenna folds in the stowed position. Inside the tower there is only one workstation for the system operator. The other two crew members are in the front of the hull. The ammunition load of the Yitian combat vehicle consists of eight missiles in two blocks of four each. After it is used up, it is necessary to remove the empty TPK and install containers with missiles in their place.
As ammunition for the Yitian air defense system, NORINCO chose the TY-90 Tian Yan guided missile. It should be noted that this missile was developed as an air-to-air weapon and was intended for the self-defense of helicopters. The missile with an infrared homing head showed its advantages during the tests and the first years of operation in the Chinese military aviation, thanks to which it was able to get to the ground anti-aircraft complex.
The TY-90 missile is a duck-type missile and is equipped with a solid-propellant engine. Its initial method of application affected the layout: the aerodynamic surfaces do not fold, which is why the transport and launch container has a square section with a side of about 30 centimeters. The starting weight of the TY-90 rocket is 20 kilograms, three of which are on the core warhead. It allows you to guarantee hitting targets at a distance of up to 4-5 meters. At large distances, the energy of the fragments may be insufficient to cause serious damage to the enemy aircraft. The solid-propellant engine accelerates the rocket to a speed of about 2300 km / h, which, combined with its operating time, gives the maximum effective launch range of 5.5-6 kilometers. The maximum height of the defeat is 5.5-6 kilometers. The maximum target speed is 400 meters per second.
The TY-90 missile has an infrared seeker with a viewing angle of ± 30 °. The head matrix transmits information to a digital computing unit capable of finding a target against the background of the earth and, allegedly, emitting target radiation in the event of heat traps. There is information about the development and, probably, testing of two new variants of the seeker for the TY-90. One of them should work in two parts of the spectrum at once, and the other is supposed to be equipped with a new matrix with better characteristics. Initially, the missile guidance system allows you to lock the target both before and after launch. As part of the Yitian air defense system, the rocket works only in the first mode.
The combat work of the anti-aircraft missile system is as follows. On the march or in position, the systems operator monitors the air situation using a surveillance radar. A fighter-type target can be detected at a range of up to 18 kilometers. For a cruise missile, this parameter is 10-12 kilometers. After detecting a target, the operator turns the tower in its direction and prepares for an attack. When the target approaches a distance of about 10-12 kilometers (the exact range at this stage depends on weather conditions and a number of other factors), the operator takes it for tracking using a thermal imaging or optical sight. After the target enters the firing zone, a rocket is launched, guided by its own equipment. The declared probability of hitting a target with one missile is 0.8.
The capabilities of the Yitian air defense system allow him to work both independently and as part of a unit. In the second case, the anti-aircraft battery usually includes six combat vehicles with missiles and one command post based on the WZ 551 armored personnel carrier with its own IBIS-80 radar station, capable of simultaneously "seeing" up to 40 targets and accompanying 12 of them. The command post is equipped with communication equipment designed to transmit data to operators of combat vehicles. Also in the anti-aircraft battery there are several auxiliary vehicles.
A special version of the combat module is intended for installation on the EQ2050 vehicle chassis. It is facilitated due to the absence of an operator's workplace and a mechanism for turning and folding the radar antenna. Such a combat module is a pylon on which a rotary unit with missile TPK, an antenna radar station and optical instruments is installed. This simplification of the design had a bad effect on the survey capabilities. The radar antenna was moved from a separate column to the front side of the turning block and placed between the blocks of transport and launch containers. Because of this, Yitian on a car chassis cannot constantly monitor the entire surrounding space: this requires turning the entire module along with the missiles. The operator's station in the version on the EQ2050 chassis is located in the cab, next to the driver. The crew was reduced to two people.
The third version of the Yitian complex is proposed for use as part of the Giant Bow-II air defense system. In this case, the launching equipment and the optoelectronic module are mounted on a towed semi-trailer borrowed from the Type 87 anti-aircraft artillery mount (Chinese modernization of the Soviet ZU-23-2). It is noteworthy that in the available images of this version of the air defense missile system, the missiles are placed on the guides, and not attached to the launcher along with the TPK. The Giant Bow-II system includes a Yitian towed semi-trailer, Type-87 anti-aircraft guns, a guidance and control point based on the EQ240 truck and auxiliary vehicles. The towed version of the Yitian air defense system is intended only for the defense of stationary objects, since its deployment takes a lot of time.
According to reports, none of the three versions of the Yitian anti-aircraft missile system has yet been adopted by the Chinese army. According to some sources, several combat vehicles and towed installations are in trial operation, but the complex is not yet the standard armament of any units. The new air defense system is actively promoting on the international market, but there is no information about supply contracts yet. Perhaps the fate of the Yitian system will be decided in the very near future, but at the moment its prospects look ambiguous.
