Back in the Second World War, attack aircraft pilots were faced with the fact that it was very difficult to get hits from guns into a single tank. But at the same time, the speed of the Il-2 was about half that of the Su-25, which is considered not too fast an aircraft with good conditions for attacking pinpoint ground targets. It is very difficult for an attack aircraft, and even more so for a supersonic fighter-bomber, to hit armored vehicles moving on the battlefield at a speed of 10-20 km / h with unguided means of destruction. At the same time, the combat aircraft itself is exposed to a serious threat from the ZSU, mobile short-range air defense systems and MANPADS. The ideal option would be an armored low-speed attack aircraft capable of delivering pinpoint strikes with guided weapons, but this was never implemented.
In the 60s, in different countries, including the USSR, guided anti-tank missiles were developed. At first, very imperfect ATGMs were guided manually by wire or by radio. The operator's task was to combine the missile tracer with a moving target, which seemed a difficult task, required a lot of training, and the percentage of misses was very high. Nevertheless, even in this case, the probability of hitting the target was significantly higher than when using unguided aircraft weapons - cannons, NAR and free-fall bombs.
In the late 50s, the USSR began to experiment with the installation of weapons on the Mi-1 helicopter. Initially, these were NAR TRS-132. Six tubular guides for ORO-132 missiles were mounted side by side. Then there were variants armed with rifle-caliber machine guns and holders for bombs weighing up to 100 kg.
It is clear that a helicopter with such weapons could not pose a serious threat to enemy armored vehicles, and even with a maximum flight speed of 160 km / h and no armor, it was a very easy target. In this regard, the designers decided to equip the helicopter with an anti-tank missile system. At that time, the most promising models were the 2K8 Phalanx and 9K11 Malyutka ATGMs.
Anti-tank complex "Phalanx" ensured destruction of targets at a distance of 2.5 km, with a minimum firing range of 500 meters. The flight speed of a rocket with a launch mass of about 28 kg was 150 m / s. The missile was guided by radio. In the tail section of the rocket, two tracers were mounted. When meeting at an angle of 90 °, a seven-kilogram cumulative warhead pierced 500 mm homogeneous armor.
ATGM 9K11 "Baby" had lighter missiles weighing 10, 9 kg with a launch range of up to 3000 m. The warhead of an ATGM weighing 2, 6 kg penetrated 400 mm armor along the normal. The "Baby" was guided by wires. The rocket speed is 120 m / s. In general, compared to the "Falanga", it was a much simpler and cheaper complex, but for use from a helicopter, its data was too low. Nevertheless, the Mi-1 equipped with six Malyutka ATGMs was presented for testing.
Soon after the adoption of the "Phalanx", the modernized ATGM "Falanga-M" with semi-automatic targeting appeared in service. After the launch, the operator had only to hold the target in the crosshair of the sight, and guidance commands were automatically generated and issued by the control equipment. In the modernized complex, the preparation time for launch was reduced, thanks to the use of more powerful engines in the ATGM, the launch range increased to 4000 m, and the rocket speed to 230 m / s. At the same time, the probability of defeat in conditions of good visibility was 0.7-0.8.
In 1962, the Mi-1MU as a whole successfully passed the tests, but by the time they were completed, the serial production of the helicopter had already been curtailed. In addition, the generals, who did not understand the advantages of a helicopter with guided anti-tank missiles, were skeptical about the combat capabilities of light dragonfly-like vehicles. In this regard, the Mi-1MU remained an experienced one.
Almost simultaneously with the work on arming the Mi-1, the development of a combat version of the Mi-4 helicopter began. Initially, the armament of the Mi-4AV consisted of holders for NAR UB-16 blocks or bombs. Later on the "four" tested the ATGM "Phalanx".
However, as in the case of the Mi-1MU, the military was in no hurry to adopt attack helicopters. Only in 1966, after the decision was made to develop the transport-attack Mi-24A, an order was issued for the Mi-4AV fire support helicopters.
The armament of the helicopter included four 9M17M "Falanga-M" ATGMs and three beam holders for six UB-16 blocks with sixteen NAR C-5s in each or six 100 kg bombs. Also, four 250 kg bombs or two ZB-500 incendiary tanks could be suspended. A large-caliber 12, 7-mm machine gun A-12, 7 was mounted in the ventral gondola.
The ATGM was at the disposal of the navigator, who launched and guided anti-tank missiles. The bombs were dropped and the NAR was used by the crew commander, who controlled the helicopter, and the flight technician led the fire from the machine gun.
Although the Mi-4AV with an ASh-82V piston engine with a capacity of 1250 hp did not have armored protection and could develop only 170 km / h, it was a completely combat-ready vehicle. In addition to weapons, the helicopter could take on board 8 paratroopers with personal weapons. In total, about two hundred "fours" were converted into the Mi-4AV version.
For the first time, the anti-tank Mi-4AV were used in battle in the Yom Kippur War. Despite the modest flight performance and high vulnerability of the "four", armed with ATGMs during the battles on the Sinai Peninsula on October 8 and 9, 1973, made more than 30 sorties. They are believed to have destroyed tanks from the Israeli 162nd Armored Division.
In general, the first experience of equipping Mi-4 helicopters with anti-tank weapons was positive. At the same time, it became quite clear that in order to increase combat effectiveness in modern conditions, a specially developed vehicle is required, which has a booking of the cabin and the most vulnerable components and assemblies, as well as special sighting and navigation equipment associated with the weapon system.
In the late 50s, it became clear that the Mi-1 helicopter was rapidly becoming obsolete and needed to be replaced. The main problem that arose when creating a new helicopter was the lack of a relatively light and economical gas turbine engine in the USSR. Especially for the Mi-2 helicopter in OKB-117 under the leadership of S. P. Izotov, the GTD-350 engine with a capacity of 400 hp was created. When designing the Mi-2, a number of units of the Mi-1 piston were used. This approach made it possible to significantly speed up the introduction of a new light helicopter into serial production. The first flight of the prototype took place in September 1961. But fine-tuning and testing of the helicopter with still damp engines dragged on until 1967.
The helicopter, equipped with a pair of GTD-350 engines, had a maximum take-off weight of 3660 kg and a passenger capacity of 10 people. The maximum speed is 210 km / h. The practical flight range without additional fuel tanks is 580 km. In general, the car in its characteristics corresponded to foreign classmates. Complaints were only caused by the relatively high fuel consumption of the GTD-350 engines.
From the very beginning, the military showed great interest in the Mi-2. In the future, in addition to reconnaissance, communications and sanitary options, it was planned to create a light anti-tank helicopter. But by the time the helicopter was ready for serial production, it turned out that its concept did not fully meet modern requirements. The ideas about the role and place of a light helicopter, formulated in the 50s and formalized in the form of a terms of reference, were outdated by the time the Mi-2 appeared. The desire to keep the dimensions of the Mi-1 piston engine imposed serious restrictions even at the design stage. It was not possible to create the Soviet Iroquois from the Mi-2 - it was not able to take on board a detachment of soldiers or the corresponding cargo. The efficiency, carrying capacity and maneuverability of the Mi-2 for a helicopter of this class left much to be desired. Back in the late 60s, experts said that different light helicopters of a new generation were needed - one should be of the Mi-4 class, the second was seen as quite small, with a capacity of 2-3 passengers. However, the Mi-2's shortcomings are not so much the fault of the designers, who did everything to improve the machine, as mistakes at the level of formulating the very concept of the helicopter and the absence in the USSR of a light gas turbine engine with high technical characteristics.
In 1966, the combat Mi-2V was developed with 4 UB-16 blocks or with the same number of Falanga-M ATGMs. However, the delay in testing the base helicopter led to the fact that the strike version was brought to an acceptable level only in the early 70s. By that time, the serial construction of the transport-combat Mi-8TV was underway, and the Mi-24A was on its way.
The loss of interest of the military was also due to the fact that the construction of the Mi-2 was transferred to Poland. Its production was set up at a helicopter plant in the city of Svidnik. The production of GTD-350 engines was entrusted to an enterprise in the city of Rzeszow. The Poles received the right, 10 years after the start of serial construction of the Mi-2, to make independent changes to the basic design and create their own versions of the helicopter.
The Vietnam War fueled interest in light helicopters equipped with small arms, cannon and missile weapons. In June 1970, Poland began testing the Mi-2 with a 23 mm NS-23 cannon mounted on the left side and two 7.62 mm PKT machine guns on the starboard side. In addition, RPK light machine guns were mounted on pivot mounts in the windows of the cargo compartment, from which a flight technician was firing. This version, designated Mi-2US, was built in small series. Following the Mi-2US, the Mi-2URN appeared. The armament of the helicopter was reinforced with 57-mm NAR blocks.
In 1972, the Mi-2URP with attachment points for four Malyutka ATGMs was handed over for testing. The operator's workplace with an optical sight and a guidance panel was located next to the pilot. Although the declared launch range of the Malyutka ATGM was 3000 m, when launched at a range of 2000 m, it was possible to hit a shield target simulating a tank in a little more than half of the cases. The reason for the low firing accuracy of the wire-guided missiles was the vibration of the helicopter, as well as the imperfection of the guidance system, designed to launch missiles from a fixed platform. Nevertheless, the helicopter was put into service, and it was serially built.
Due to the low combat characteristics and low security, the armed versions of the Mi-2 did not interest the Soviet commanders. But this did not prevent supplies to other Warsaw Pact countries. Thus, Polish specialists managed to realize what they had abandoned in the USSR. Mil OKB in the early 70s was overloaded with orders, and the military did not find the light anti-tank helicopter interesting. The Mi-2, if it were equipped with more powerful engines and long-range ATGMs with a semi-automatic guidance system, could be good as a light, inexpensive combat helicopter.
In 1960, the development of a medium-sized transport and landing helicopter with gas turbine engines began; in the future, this machine was supposed to replace the piston Mi-4. Serial construction of the helicopter, designated Mi-8, began in the first half of 1965 at an aircraft plant in Kazan. In 1969, the Mi-8 completely replaced the Mi-4 in production. For its time, the Mi-8 was an outstanding aircraft, with very good flight performance, advanced equipment and high modernization potential. This predetermined the long life of the helicopter, which was built in large series and the creation of numerous modifications.
Helicopter Mi-8T, equipped with two TV2-117 engines, power 1500 hp. each, developed a maximum speed of 250 km / h. With a maximum takeoff weight of 12,000 kg, the helicopter could transport a cargo weighing 4,000 kg and had a practical flight range of 450 km.
In 1968, an armed modification of the Mi-8TV was created on the basis of the transport and landing Mi-8T. The G8 armament set had previously been tested on the Mi-4AV. The combat-transport Mi-8TV, presented for testing, received lighter and cheaper Malyutka ATGM with a shorter launch range. It also provided for the suspension of NAR blocks and bombs with a total weight of up to 1500 kg.
Compared to the Mi-4AV, the caliber of the bombs used has significantly increased. These could be bombs weighing 100, 250 and 500 kg, including one-time cluster bombs equipped with PTAB. Thus, in terms of strike potential, the helicopter was not inferior to the MiG-21 fighter and against tanks, in addition to ATGMs, NAR S-5K / KO with a cumulative warhead and PTAB in RBK-250 and RBK-500 could be used.
The conditions for searching for targets and targeting weapons on the helicopter were generally better than on the fighter-bomber. But at the same time, the pilot who launched the NAR and the navigator who guided anti-tank guided missiles, when searching for targets, had to rely only on their own eyesight. The combat value of a fairly large helicopter was reduced by the fact that the G8 with ATGM was very vulnerable to anti-aircraft systems and fighters. Due to the significant weight, such an ATGM technique as hovering a helicopter and shooting using terrain folds turned out to be difficult to implement.
The first anti-tank modification of the G8 had solid armor protection. The cockpit was protected from bullets and shrapnel by removable armor plates 8 mm thick. The armor was also mounted in the bulkhead on the side of the cargo compartment. The pilot's and navigator's seats had armored cups and armored backs. Part of the cockpit glazing was made of transparent armor 50 mm thick. The fuel pumps and hydraulic units of the control system were partly armored. The fuel tanks were sealed.
Initially, the A-12, 7 machine gun with 700 rounds of ammunition was introduced into the armament of the Mi-8TV. The installation of a large-caliber machine gun heavily cluttered the cockpit. Due to the lack of space, the ammunition had to be placed in a cartridge box on the front wall of the cargo compartment, and the tape had to be pulled along the outer sleeve. However, this was later abandoned, replacing the A-12, 7 with a PC rifle caliber machine gun. For firing at armored vehicles, the 12.7 mm machine gun was weak, and when used against manpower, it had no advantages over the 7.62 mm machine gun. In addition, the use of machine-gun weapons in hostilities was of an episodic nature, and it was considered not rational to carry a dead load in the form of a machine-gun mount with an ammunition load of about 130 kg. When firing from the A-12, 7, after about 100 shots, due to the high gas content in the cockpit, it became impossible to breathe. In general, a large-caliber machine gun was not popular with helicopter crews, and, as a rule, they flew without it.
In 1974, the Mi-8TV was equipped with the Falanga-M ATGM with the Raduga-F guidance system, which were more suitable for use from a combat helicopter. As a result, the transport-strike Mi-8TV, intended for its own army aviation, was supplied to the Allies with the Mi-8TB with the Malyutka ATGM.
Relatively few Mi-8TV helicopters were built, due to similar weapons, they were most often used in regiments that had Mi-24s. The reason for the limited series of Mi-8TV was that on this modification, due to the large mass of weapons and armor, flight data significantly deteriorated, and the carrying capacity and flight range decreased. The cockpit was overly cluttered with weapons, an ATGM guidance system and other sighting equipment. So, for the use of various weapons in the cockpit, there were four sights. As a result, in the front regiments, starting from the late 70s, installations with large-caliber machine guns and bulky ATGM guidance equipment were gradually dismantled. This made it possible to reduce the flight weight of the helicopters, which had a positive effect on flight data, improve the working conditions of the crew and concentrate on direct functions for the delivery of cargo and paratroopers, and, if necessary, provide fire support to ground units.
In the future, the use of guided weapons on the Mi-8MT / MTV variants with more powerful TV3-117MT and TV3-117VM engines was abandoned for some time, focusing on increasing the carrying capacity, reliability, range and dynamic ceiling. However, the small arms, external suspension assemblies of the NAR and bombs on the "eights" were preserved.
In 2009, the transport-strike Mi-8AMTSh (export designation Mi-171Sh) was adopted in Russia. The helicopter uses two TV3-117VM turboshaft engines with a take-off power of 2,100 hp, the modernized Mi-8AMTSh-V, which went to the troops since the summer of 2014, - two VK-2500-03 with an improved transmission.
The armor protection of the helicopter is reinforced with lightweight metal-ceramic armor. The helicopter received a new avionics complex, which, among other things, includes a weather radar, pilot's night vision goggles, a thermal imager and satellite navigation equipment. Thanks to this, the Mi-8AMTSh has the ability to operate at night.
The basic version of the Mi-8AMTSh armament includes 20 charging blocks of 80-mm NAR S-8 and suspended containers with 23-mm GSh-23L cannons on 4-6 beam holders and two 7.62-mm PKT machine guns in the bow and feed installations. If necessary, the helicopter can be armed with the Shturm-V complex with 9M114 or 9M120 guided missiles. This makes it possible to relatively inexpensively turn a transport-combat helicopter into an anti-tank one. What may be of interest to countries that have Mi-8 / 17s, but no specialized combat helicopters.
