What is the FAB-500 Bomb? Can This Bomb Bring Victory to Russia in Ukraine?

Since February 24, 2022, Moscow has not been able to gain air superiority since the beginning of the Russian-Ukrainian War, and it seems that the operational concept of using modern ammunition, which has the potential to change the course of the war, has not yet reached the desired level. I examined the technical shortcomings of the Russian Air Force in this war in detail in my article titled "Why the Russian Air Force 'Failed' in Ukraine?" published on STRASAM on December 10, 2023 (https://strasam.org/savunma/askeri-harekat/rus-hava-kuvvetleri-ukraynada-neden-basarisiz-oldu-2662). In summary, I summarized the dilemmas and technical problems of the Russian Air Force under four headings: 

1) The difficulty of hitting targets with conventional bombs at high altitude,

2) Insufficient number of precision-guided munitions to be fired at high-altitude targets,

3) Low altitude air-to-ground attack and close air support,

4) Lack of defensive pressure capability to protect attack aircraft. 

When the Russians introduced guided versions of the FAB-500 general purpose bomb in the spring of last year in the context of the second point, "Insufficient number of precision-guided munitions to be dropped on targets at high altitude", it almost led to the expectation that a weapon that could change the course of the war had been fielded. The first bomb was dropped on March 24, 2023, after which the Russians began to expend about twenty FAB-500 bombs on a daily basis. However, it seems that the wheels of the Russian defense industry were not yet turning fast enough to mass-produce such modern munitions quickly enough. However, nowadays, there are reports from the front that the Russians are once again using guided versions of the FAB-500 bombs. 

What are the characteristics of the FAB-500 bomb?

The FAB-500 is a classic general purpose bomb in its own right. It has a similar structure to the American general purpose bombs MK-82 (500 lbs.) and MK-83 (1,000 lbs.) and has a weight value between the two (814 lbs. - 370 kg.) and the warhead of this bomb contains 250 kg. of explosives. The Soviets began using this type of general purpose bomb in 1932. A low-friction version of the FAB-500 bomb was developed in 1962, which could be dropped by all Soviet bombers. The body of the ammunition was made of cast iron, which was cheaper than steel, to make it easier to disintegrate when the bomb exploded upon contact with the ground. 

The bomb's fin mechanism, which works in an integrated structure with the guidance system, allows this bomb, which has a range of 1-2 km in free fall, to be dropped on targets 50-70 km away. Compared to the Western versions of the AGM-84K SLAM-ER, Storm Shadow/SCALP, Taurus, AGM-154 JSOW, AGM-158 JASSM, KEPD-350 and the Turkish-made SOM missile, the FAB-500 has a much lower range than the JDAM GBU-38. 

As many other countries do, the Russians, too, are turning mindless bombs into smart ones by attaching a Winged Guidance Kit (KGK) to their general purpose bombs. The FAB-500 is a bomb modernized in this context. Thus, a winged guidance kit is used to turn a conventional 800-pound general purpose bomb into a long-range air-to-ground smart munition. This not only gives the existing bombs a range of up to 70 km in all weather conditions, but also a high-precision strike capability up to a deviation of 4-7 meters. This enables Russian aircraft to hit targets in the depths behind the Ukrainian frontline from behind the front line, and to carry out isolation and combat airspace isolation missions without putting themselves at risk.

The Russian-made Winged Guidance Kit converts the FAB-500 general-purpose bombs into long-range, smart, long-range, at-hold bombs. The approximate cost of this conversion is 300,000 rubles, equivalent to $3,300. After the collapse of the USSR, Russia kept most of its FAB-500 general purpose bombs in warehouses. Now, with the winged guidance kits installed on these bombs, it was possible to turn these bombs into smart munitions. 

These bombs, which can easily find their targets thanks to their INS/GPS guidance system when dropped on their targets by aircraft flying in the 5-30 thousand feet altitude range, can hit their targets with high accuracy in proportion to the accuracy of the coordinates of the targets provided by Russian intelligence. It should be noted that making a "smart" bomb out of the FAB-500 is a brilliant idea. This bomb can create a small crater 8 meters in diameter and 3 meters deep after a 213 kg warhead explodes upon contact with the ground.

According to Russian sources, the FAB 500m-62 High Explosive Guided Bomb is designed for the destruction of military-industrial areas, railway junctions, logistics facilities, supply depots, personnel in open terrain, as well as light armored vehicles on the march or during an attack within the main concentration perimeter. A derivative of this bomb, the KAB-500-OD, has an electro-optical TV guidance system.

The 'wings' attached to the FAB bombs as part of the guidance and navigation system allow for low-altitude cruise and, in a way, enable the bomb to penetrate its target while traveling at low speeds without being visible to the radars of enemy defense weapons and systems. These bombs, which can be produced much more easily and cheaply than ballistic and cruise missiles/guided bombs, are considered to be a good option to meet the modern ammunition needs of the Russian Air Force, which has apparently not reached the desired level in terms of modern ammunition.

Conclusion

Despite having the capability to convert conventional or general purpose bombs into smart bombs, Russia generally did not prioritize the use of modern munitions in Ukraine due to its operational concept that emphasizes quantity over quality in the use of munitions. Insisting on this concept cost the Russian Army a large number of fighter jets and attack helicopters. Starting last year, Russia started firing guided munitions in addition to ballistic and hypersonic missiles, and various reports indicate that Russia used around 20 modern munitions every day last year. 

Today, it is understood that Russia has accelerated the production of modern ammunition, and the pace of transforming its conventional ammunition into smart ammunition with winged guidance kits has also increased. Like the 500 kg. FAB-500, the 1,500 kg. (3,300 lbs.) FAB-1500M-54 guided bomb is now in use. The guided versions of the FAB-1500M-54 bombs, which are about 1,300 pounds heavier than the MK-84 based guided bombs used in the Western world, are expected to be used to hit strategic targets on the Russian-Ukrainian front. Thus, although the cost of war for Russia will increase slightly, I expect that the use of modern ammunition, which ultimately means fewer aircraft losses, will increase the effectiveness of the Russian Air Force.

References

https://kintex.bg/product-4-49

Rosoboronnexport, Russian Defense Export, Aerospace Systems, KAB-500-OD, https://roe.ru/eng/catalog/aerospace-systems/air-bombs/kab-500-od/

Topwar, FAB-500: the legendary aerial bomb that "became smart", May 12, 2023, https://tr.topwar.ru/216762-fab-500-legendarnaja-aviabomba-kotoraja-poumnela.html