Russian RBK‑500 bombs: An old weapon's deadly resurgence in Ukraine

A video has surfaced on the internet showing the use of a Russian RBK-500 bomb equipped with a UMPK module. These are cluster warhead designs capable of targeting broad areas. We present their performance.

A video has surfaced on the internet showing the use of a Russian glide bomb designed for area targeting, based on RBK-500 bombs enhanced with the UMPK module (Unified Module Kit for Planning and Correction).

This gives new life to an old solution from the 1980s, whose use under current conditions would be suicidal for Russian pilots. They pose a significant problem for Ukrainians due to their wide-area targeting capability.

RBK-500 bombs, weighing around 500 kg, contain a cluster warhead banned by many countries worldwide. Depending on the version, they house hundreds of bomblets. An example payload includes 126 bomblets, such as AO-2.5RT, OAB-2.5RT, OFAB-50UD, or OFAB-2.5, intended to combat enemy forces. For AO-2.5RT bomblets weighing slightly over 2 kg, the fragment range is about 30 metres for soldiers in the open field or 10 metres for those hidden in trenches.

The second payload includes 268 anti-tank PTAB-1M bomblets weighing less than 1 kg. They can penetrate about 20 cm of armoured steel, allowing them to destroy a wide range of armoured equipment. However, this is a single-warhead solution, so a net or cage over the vehicle provides protection.

There are also dual-purpose variants similar to the American DPICM, dedicated to destroying fortifications BetAB-M, igniting ZAB-2.5, or self-guiding SPBE-D bomblets with an infrared head in the latest versions.

UMPK modules are a Russian copy of the American JDAM-ER solution, which has unfortunately proven highly effective in Ukraine. UMPK modules include a section containing a guidance system based on satellite and inertial navigation and a part with folding wings and control surfaces.

Thanks to this, when released from an altitude of over 10,000 metres, the bombs can glide for even tens of kilometres and hit the target with an accuracy of within tens of feet. The best way to stop them is to shoot down the aircraft carrying them before it releases them.

Due to the long gliding range, the bombs can be dropped outside the range of most anti-aircraft defence systems. Only medium-range solutions like the S-300, Patriot, or SAMP/T are effective, but Ukrainians have too few of these or have run out of missiles for them.