In the olden days aerial bombs were quite simple. A bomber would fly over a target and drop its load – a bunch of bombs would fall out the aircraft’s belly and free fall all the way to the ground where they would explode taking out the target. When the Soviet-era FAB-500 was new in 1954, it worked exactly like that. But it evolved since then and is actually still getting improved.
FAB-500 is a Soviet/Russian air-dropped bomb that weighs 500 kg – you could’ve guessed it from its name. The weight of the explosive material is actually just 300 kg, but it is a devastating bomb. And has been since 1954. In fact, there are two versions of the FAB-500.
The original M-54 was made to be carried in internal bomb bays, while the M-62 is more aerodynamic and is meant to be hung on external hardpoints. The latter one is more common now as the entire concept of the old-fashioned bomber slowly descends into obscurity.
Removal of an unexploded FAB-500 bomb in Zaporizhia region. Failure to detonate is quite common for these bombs. Image credit: State Emergency Service of Ukraine via Wikimedia (CC BY 4.0)
However, the FAB-500s that are currently being used against Ukraine, are not the same ones that were introduced in the 1950’s or the 1960’s.
Russia has converted them to glide bombs. Instead of falling straight down, they glide quite far away from the drop site. This means that Russian aircraft do not have to come into the Ukrainian air defence zone. FAB-500s now glide into Ukrainian territory and are pretty much impossible to shoot down.
Most of the unexploded Russian bombs in Ukraine are collected and detonated somewhere safe. This is the safest and most effective way to get rid of them. And FAB-500s fail to explode quite often, especially if they fall on soft soil. But even if they do explode, their debris is studied thoroughly.
In October of this year, fragments of a FAB-500 bomb were collected near Orikhiv in the Zaporizhia region. The markings on them indicate that this bomb was assembled in 2023. After comparing some of the components with those found earlier (for example, with the 2022 bomb previously found in Bakhmut), Ukrainian and British experts found that the Russians are continuing to improve their FAB-500, as reported by Tech.wp.pl.
There is 300 kg of explosive material in this bomb. Image credit: State Emergency Service of Ukraine via Wikimedia (CC BY 4.0)
For example, the Komet-M navigation module, which is intended for drones, was found in the bomb found in October. The bomb’s electronics are powered by two batteries that also power the aerodynamic control surfaces.
The flight control of the bomb is carried out by the so-called UMPK module – an accessory that turns a dumb bomb into a smart one. The Russians likely drew inspiration from the American JDAM when developing the UMPK.
The British research group Conflict Armament Research found that the Russians increased the range of the bomb by 35-40 km during the latest updates to the FAB-500.
By the way, an interesting fact – it seems that the Russians deliberately removed the identification marks of some electronic components in order to hide their origin. Who can say whether they are trying to mislead the Ukrainians and their Western partners, or whether they don’t want rumours about the use of foreign electronics to spread from factories in Russia itself.
Written by Povilas M.
Sources: Tech.wp.pl, Wikipedia