Worse than the "Volcano"
“Slightly lower the nose of the car, gently turn on the target so that it is easily caught in the mark of the sight. You press the trigger for a split second and you get the feeling that the plane is shaking a giant, but you can clearly see how a firestorm flies to the ground. At this moment, the enemy, although conditional, cannot be envied, ”the pilot of the Russian Air Force shared with the Military Industrial Courier his impressions of using a six-barreled GS-6-23 aircraft cannon.
The GSH-6-23М of a millimeter 23 caliber with a rate of 10 000 rounds per minute was developed by two great Russian weapons designers Arkady Shipunov and Vasily Gryazev in the early 70's. Since the introduction of the “six-barred GSH” into service in 1974, its carriers have become the legendary front bombers Su-24 and the equally well-known supersonic heavy MiG-31 interceptors.
From "canister" to "Vulcan"
In the middle of the 50-s, when the first self-guided missiles, such as the American AIM-9 "Sidewinder", began to come into service with the fighters, aviation experts began talking about the fact that machine guns and cannons on combat aircraft would have to be abandoned in the near future. In many ways, such conclusions were based on the experience of the last Korean war, where jet fighters fought en masse for the first time. On the one hand, it was the Soviet MiG-15, on the other - the American F-86 Saber, F9F Panther, etc. MiGs armed with three guns often lacked a rate of fire, and the Saabram - the range, sometimes also the power of six 12,7-mm machine guns, which they possessed.
It is noteworthy that the newest at the time American F-4B carrier-based fighter "Phantom-2" had only rocket armament, including the ultramodern Sparrow AIM-7 of medium range. The guns adapted to the needs of the US Air Force F-4C were also not installed. True, in Vietnam "Phantoms" were initially opposed by Soviet cannon armament, which only had cannon armament, which the Vietnamese pilots sought to conduct short-range air combat in order not to get hit by guided missiles.
In “dog fights”, as in the western aviation slang, such fights are called, American assists were not always helped by those considered to be the best AIM-9 short-range missiles with a thermal homing head at that time. Therefore, the commanders of the air force, as well as naval aviation and the Marine Corps, had to urgently develop new tactical methods of fighting the Vietnamese fighters, first of all to re-equip the "Phantoms" with suspended cannon containers with 20-mm M61 "Vulcan" cannon. And soon the F-4E fighter entered the USAF. One of the main differences between the new model was the six-barrel Volcano, which is nominally installed in the nose.
In a number of recently published studies on the Vietnam air war, it is argued that the decision to equip the “Phantom-2” with a gun mount is not due to the need to combat the Vietnamese MiGs, but to make the fighter more suitable for strikes against ground targets. For an impartial evaluation, it’s worth referring to the numbers. According to the Pentagon, for all the time of the war in Southeast Asia, cannon armament of American fighters was shot down from 39 to 45 of Vietnamese fighters, including supersonic MiG-19 and MiG-21. And in total, according to American military historians, North Vietnam lost the 131 MiG, so aircraft cannons account for 35 – 40 percent of the total number of vehicles shot down by US pilots.
Whatever it was, it was from the appearance in the F-4E "Phantom-2" cannon armament, rejected at the end of 50-s, began to return to the arsenal of fighters, fighter-bombers, reconnaissance aircraft and other machines.
One of the most popular in the arsenal of the Western Air Forces was the already mentioned M61 Vulkan. It is noteworthy that the American fighter of the fifth generation F-22 "Lightning" is also armed with this six-barreled cannon, albeit specially upgraded.
The American company General Electric, which developed and produces Vulkan, has never worked on small-scale samples before. weapons. Moreover, the main activity of the company has always been electrical equipment. But immediately after the Second World War, the US Air Force opened a promising topic for the creation of aircraft cannons and machine guns, the rate of which was to be at least 4000 rounds per minute, while the samples were required long range and high accuracy with strikes on aerial targets.
In the traditional schemes of small arms to implement such customer requests was quite problematic. Here we had to choose: either high accuracy, firing range and accuracy, or rate of fire. As one of the solutions, the developers proposed adapting the so-called Gatling canister, which was used in the United States during the Civil War, to modern requirements. At the heart of this design lay the scheme of the 1862-barrel rotary unit developed by Dr. Richard Gatling in the 10 year.
Surprisingly, despite the participation in the competition of famous developers and manufacturers of weapons, the victory went to "General Electric". When implementing the Gatling scheme, it became clear that the most important part of the new installation is an external electric drive that rotates the barrel assembly, and with its development, having a wealth of experience, General Electric managed better than its competitors.
In June, 1946, the company, having defended the project before a special commission of the US Air Force, received a contract to implement its scheme in hardware. This was already the second stage in the creation of new aviation rifle systems, where Colt and Browning firms were also to take part.
In the course of research, testing and development work, the company had to experiment with the number of barrels (at different times it varied from 10 to 6), as well as with gauges (15,4 mm, 20 mm and 27 mm). As a result, the military was offered a six-barrel millimeter caliber 20 cannon, with a maximum rate of 6000 rounds per minute, producing 110-gram shells at speeds in excess of 1030 meters per second.
A number of Western researchers argue that the choice in favor of the 20 caliber of millimeters was due to the customer’s demand, the US Air Force, who had arisen at the beginning of the 50's and considered that the gun must be sufficiently universal, equally suitable for aimed fire on both airborne and ground forces. goals.
27-mm shells were well suited for firing on the ground, but when they were used, the rate of fire dropped sharply and the recoil increased, and later tests showed the relatively low accuracy of such-caliber guns when firing at air targets.
The 15,4 caliber shells of millimeter had too low power against the intended enemy on the ground, but a gun with such ammunition provided good firing rates, albeit with an insufficient range for air combat. So the developers at General Electric stopped at a compromise caliber.
The six barrels of the Volcano M1956 cannon, which were put into service in 61, were concentrically assembled into a single block, which rotated clockwise, together with the bolts. In one turn, each barrel was consistently reloaded, and a shot was fired from the barrel, which was at the top at that moment. The whole system worked at the expense of an external electric drive with a power of 26 kW.
True, the military was not entirely satisfied with the fact that the mass of the gun eventually turned out to be almost 115 kilograms. The struggle for weight loss continued for many years, and as a result of the introduction of new materials, the М22А61 model installed on the F-2 "Raptor" weighs a little more than 90 kilograms.
It is noteworthy that at the present time in the English-language literature all the rifle systems with a rotary block of barrels are called Gatling-gun - “Gatling’s Gun (Gun)”.
Soviet multifolk
In the USSR, work on the creation of multi-barreled aircraft guns were going on before the Great Patriotic War. True, ended in vain. The idea of a system with trunks, brought together in one block, which would be rotated by an electric motor, Soviet gunsmiths came at the same time with American designers, but then we had a failure.
In 1959, Arkady Shipunov and Vasily Gryazev, who worked at the Klimovsky Scientific Research Institute-61, joined the work. As it turned out, the work had to start virtually from scratch. The designers had information that a “Volcano” was being created in the USA, but not only the technical solutions used by the Americans, but also the tactical and technical characteristics of the new western system remained secret.
True, Arkady Shipunov himself later admitted that even if he and Vasily Gryazev had become aware of American technical solutions, they would hardly have been able to apply them in the USSR anyway. As already mentioned, the designers of General Electric connected to the Vulcan an external electric drive with a power of 26 kW, while Soviet aircraft manufacturers could only offer, as Vasily Gryazev himself put it, “24 volts and not a gram more.” Therefore, it was necessary to create a system that does not work from an external source, but using the internal energy of the shot.
It is noteworthy that similar schemes were proposed at the time by other American firms participating in the competition to create a promising aviation gun. True, Western designers could not implement such a solution. In contrast, Arkady Shipunov and Vasily Gryazev created the so-called vapor engine, which, according to the second participant of the tandem, worked like an internal combustion engine - took some of the powder gas from the barrels when fired.
But, despite the elegant solution, another problem arose: how to make the first shot, because the gas exhaust engine, and hence the gun mechanism itself does not work yet. For the initial impulse, a starter was required, after using which, from the first shot, the gun would operate on its own gas. Later, two versions of the starter were proposed: pneumatic and pyrotechnic (with a special actuator).
In his memoirs, Arkady Shipunov recalls that even at the beginning of work on a new aircraft gun, he was able to see one of the few photographs of the American Vulcan being prepared for testing, where he was struck by the fact that the ammunition ribbon was spread along the floor, ceiling and walls of the compartment, but was not consolidated in a single cartridge box. Later it became clear that at a rate of fire in 6000 shots per minute, a void is formed in a cartridge box in a matter of seconds and the tape begins to “walk”. In this case, the ammunition falls, and the tape itself is torn. Shipunov and Gryazev developed a special pneumatic tape-bearing that does not allow the tape to move. Unlike the American solution, this idea provided a much more compact placement of guns and ammunition, which is especially important for aircraft, where designers are fighting for every centimeter.
In goal, but not immediately
Despite the fact that the product, which received the AO-19 index, was practically ready, there was no place for him in the Soviet Air Force, as the military itself believed: small arms are a relic of the past, and the future belongs to missiles. Shortly before the Air Force abandoned the new gun, Vasily Gryazev was transferred to another enterprise. It would seem that AO-19, despite all the unique technical solutions, will remain unclaimed.
But in 1966, after summarizing the experience of the North Vietnamese and American air forces in the USSR, it was decided to resume work on the creation of promising aircraft guns. True, by that time almost all enterprises and design bureaus that had previously worked on this topic had already shifted to other areas. Moreover, there were no people willing to return to this line of work in the military-industrial sector!
Surprisingly, despite all the difficulties, Arkady Shipunov, who had headed TsKB-14 by this time, decided to revive the cannon theme at his enterprise. After the approval by the Military Industrial Commission of this decision, its leadership agreed to return Vasiliy Gryazev and several other specialists who participated in the work on the AO-19 product to the Tula enterprise.
As Arkady Shipunov recalled, the problem with the resumption of work on cannon aircraft weapons arose not only in the USSR, but also in the West. In fact, at the time of the multi-barreled guns in the world was only American - "Volcano".
It is worth noting that, despite the abandonment of the “AO-19 object” of the Air Force, the product was interested in the Navy, for which several gun complexes were developed.
By the beginning of the 70-s, the KBP proposed two six-barrel guns: the 30-mm AO-18, which used the cartridge AO-18, and the AO-19 for 23-mm ammunition AM-23. It is noteworthy that the products differed not only by the used projectiles, but also by starters for the preliminary acceleration of the block of barrels. On AO-18 there was a pneumatic, and on AO-19 - pyrotechnic with 10 pyrocartridges.
Initially, representatives of the Air Force, who viewed the new AO-19 as a weapon for promising fighters and fighter-bombers, presented increased demands for shooting ammunition - no less than 500 shells in one queue. I had to seriously work on the survivability of the gun. The most loaded part, the gas rod, made of special heat-resistant materials. Changed the design. The gas engine was refined, where so-called floating pistons were installed.
Conducted preliminary tests showed that the modified AO-19 can show much better characteristics than originally stated. As a result of the work carried out in the KBP, the 23-mm gun was able to fire at the rate of fire of the 10 – 12 thousand rounds per minute. And the mass of AO-19 after all the refinement was a little over 70 kilograms.
For comparison: the American Vulcan, modified by this time, received the M61А1 index, weighed 136 kilograms, made 6000 shots per minute, the volley was almost 2,5 times smaller than the AO-19, while the American aircraft designers also needed to deploy more aircraft and 25-kilowatt external electric drive.
And even on the МХNUMXА61, which is aboard the fifth-generation fighter F-2, American designers with lower caliber and rate of fire of their gun could not achieve those unique indicators in mass and compactness, like the gun developed by Vasily Gryazev and Arkady Shipunov.
Birth of a legend
The first customer of the AO-19 cannon was the Sukhoi Experimental Design Bureau, which at that time was headed by Pavel Osipovich himself. The Sukhie planned that the new gun would become a weapon for the promising front-line bomber with the variable geometry of the T-6 wing, which later became the legendary Su-24.
The timing of work on the new machine was quite short: the 17, which made the first flight of January 1970, in the summer of the 1973-th T-6 in the summer was already ready to be transferred to military testers. When fine-tuning the AO-19 to the requirements of aircraft manufacturers, certain difficulties arose. Well fired at the stand, the gun could not give a queue more than 150 shots - the barrels overheated, they needed to be cooled, which often took about 10 – 15 minutes, depending on the ambient temperature.
Another problem was that the gun did not want to, as the designers of the Tula Instrument Design Bureau joked, "stop shooting." After releasing the start button, the AO-19 managed to spontaneously launch three or four rounds. But within the allotted timeframe, all the flaws and technical problems were eliminated, and in the GLITS of the Air Force, for tests, the T-6 was presented with a gun fully integrated into the new front bomber.
In the course of the trials that began in Akhtubinsk, the product, which by then had received the GSh (Gryazev - Shipunov) -6-23 index, was shot at various targets. With the control application of the latest system in less than one second, the pilot was able to completely cover all targets, firing around 200 shells!
Pavel Sukhoi was so satisfied with the GSH-6-23 that, along with the Su-24 standard installed in the Su-6 ammunition, the so-called SPSP-6 suspended cannon containers with the HSH-23-45М cannons, capable of deflecting horizontally and vertically by XNUMX, were included . It was assumed that with such armament, and just on the front-line bomber it was planned to deploy two such installations, he would be able to completely disable the runway in one run, as well as destroy a convoy of motorized infantry in combat vehicles up to one kilometer long.
Developed at the Dzerzhinets plant, SPPU-6 has become one of the largest mobile cannons. Its length exceeded five meters, and the weight with ammunition from 400 shells was 525 kilograms. The tests showed that when firing a new installation on each running meter accounted for at least one hit of a projectile.
It is noteworthy that immediately after the “Sukhoi” they became interested in the Mikoyan Design Bureau, which intended to use the GSH-6-23 on the newest supersonic MiG-31 interceptor. Despite its large size, aircraft manufacturers needed a fairly small gun with a high rate of fire, as the MiG-31 had to destroy supersonic targets. In the KBP, the Mikoyan helped by developing a unique lightweight conveyor-free powerless system, which made it possible to reduce the mass of the gun by several kilograms and win additional centimeters of space on board the interceptor.
Developed by outstanding gunsmiths Arkady Shipunov and Vasily Gryazev, the GS-6-23 automatic aircraft gun still remains in service with the domestic Air Force. Moreover, in many ways, its characteristics, despite the more than 40-year service life, remain unique.
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