FAB with UMPK-R: Inexpensive, Long-Range, High-Precision Munition
Smart "cast iron"
One of the "discoveries" of the Russian special military operation (SVO) in Ukraine was the aerial bombs equipped with a unified planning and correction module (UMPK). The most actively used with the UMPK are the high-explosive aerial bombs (FAB) FAB-250 and FAB-500, weighing 250 and 500 kilograms respectively, as well as the disposable bomb clusters RBK-500 and the volume-detonating aviation ODAB-500 ammunition.
Somewhat less frequently, the FAB-1500, ODAB-1500 and FAB-3000 are used with the UMPK, which have a significantly greater warhead power. It is characteristic that for a long time a number of experts spoke about the uselessness of developing the UMPK for high-power aerial bombs, however, as the practice of the SVO has shown, in some cases they cannot be avoided - only the FAB 1500 and FAB-3000 can "lay" heavily fortified strongholds and Soviet-built factory workshops "into dust", so that no surviving enemy soldiers remain under the ruins.
FAB-3000 with UMPC
Following the aerial bombs with UMPK, the universal gliding inter-service munition (UMPB) D-30SN was created, which can be used both by dropping it from tactical aircraft and from ground-based multiple launch rocket systems (MLRS) "Smerch" of 300 mm caliber. Nevertheless, based on open sources, the UMPB is clearly used less often than FAB with UMPK, which is most likely due to the complexity of production and, accordingly, the increased cost of this munition.
Considering that in the vast majority of cases high-explosive aerial bombs are used with the UMPK, then in the future in this article we will say: “FAB with UMPK”.
Use of four UMPB D-30SN. Photo Telegram / Aviahub34
The enemy immediately "appreciated" the Russian FABs with UMPKs - largely due to these munitions, the line of combat contact wavered and crawled towards the Dnieper. FABs with UMPKs smash strongholds into dust, collapse buildings in which the enemy has fortified. From the moment they are used, enemy ground units can expect at any moment to meet an inglorious end, without the opportunity to even try to engage in combat.
However, the risks for aircraft using FAB with UMPK are gradually increasing. This is due to the transfer of the latest anti-aircraft systems by NATO countries to Ukraine. missile complexes (air defense missile systems) and F-16 fighters.
The Armed Forces of Ukraine (AFU) are still afraid to use F-16 fighters to hunt Russian aircraft - on our side, they are eagerly awaited. But everything can change at any moment. On the other hand, the use of ambush tactics for the use of SAM systems creates an increased threat to our aircraft, since the more FAB with UMPK is used, the more routine this work becomes for pilots, the higher the likelihood that someone will make a mistake.
In addition, the increase in the number of FABs with UMPK used leads to an increased consumption of the resources of expensive 4+ / 4++ generation aircraft, such as the Su-30SM, Su-34 and Su-35 - after all, the cost of using FABs with UMPK includes not only the cost of the ammunition itself, but also the cost of the flight hour of their carriers.
Minimizing the risks
To minimize the costs of using FAB with UMPC, we considered the possibility of creating highly specialized combat aircraft with a lower cost per flight hour compared to the above-mentioned multifunctional aircraft Su-30SM, Su-34 and Su-35.
Potentially, one of the most inexpensive carriers of FAB with UMPK could be the Yak-130 combat training aircraft
The problem is that highly specialized combat vehicles do not solve the problem of risks for combat aircraft and their pilots in the event that the enemy uses ambush tactics using air defense missile systems and/or F-16 fighters.
Another option is to use unmanned aerial vehicles (UAVs), such as the Grom UAV, for dropping FABs from the UMPK, which we discussed earlier in the article “Thunder” over Ukraine: a promising UAV can become the most effective carrier of aerial bombs with UMPCThe advantage of using UAVs to employ FABs with UMPK is the ability to enter enemy territory without risking the lives of pilots, especially if the UAV design incorporates measures to reduce visibility.
However, the prospects of the Grom UAV still look somewhat vague, and, judging from the latest images of this aircraft, it seems that the developers have decided to abandon stealth. Why? It is difficult to say, but the latest versions of the Grom UAV mockups are more reminiscent of the Soviet Strizh family of UAVs, previously used by the Ukrainian Armed Forces to strike our territory.
Early (left) and current (right) mockups of the Grom UAV
However, if the simplification of the design allows the Grom UAV to go into production faster, then this decision can be considered justified - any version of the Grom UAV would be very effective as a carrier of the FAB with the UMPK.
Another option for minimizing risks for aircraft carrying FABs with UMPKs is to try to drop them to the enemy from the maximum possible distance, but this requires raising the FAB with UMPKs to the maximum altitude and accelerating to the maximum possible speed.
Theoretically, the MiG-25/MiG-31 family of aircraft can handle this best, as we discussed earlier in the article Reincarnation of MiG-25, however, there are several complications here.
Firstly, we have a limited number of MiG-31 aircraft, so it is not very practical to spend this valuable resource to drop FAB from the UMPK, and the possibility of restoring MiG-25 aircraft from storage is questionable, since the availability and technical condition of these machines is unknown. In any case, this will take a significant amount of time.
The MiG-25RB could have become an effective and mass-produced FAB carrier with UMPK, if we had it...
Secondly, the limiter may be the design of the FAB with the UMPK, or more precisely, its ability to withstand mechanical and thermal loads that occur when dropped at high altitude and at high speed.
Another way to minimize risks for carriers is to increase the range of the FABs with UMPKs themselves, and here too there are various approaches to solving this issue.
Engine for an aerial bomb
Currently, based on information posted in open sources, the range of use of FAB with UMPK varies from 50 to 70 kilometers, depending on the type of aerial bomb, the parameters of the carrier and the target being hit. Recently, information has appeared that the range of use of individual FAB samples with UMPK reaches 85 kilometers.
Of course, the simplest way to increase the range of FAB with UMPK is to equip them with a small-sized engine, but this raises a number of problems and questions.
Inexpensive electric motors powered by batteries are clearly not suitable here, both because of the size and weight of the FAB with UMPK, and because they are dropped from high altitudes - the batteries will simply freeze, and it is risky to hang fire-explosive lithium batteries on aerial bombs.
The ability of small-sized piston internal combustion engines (ICE) to pull the “carcass” of the FAB with the UMPK is also in question; in addition, problems may arise with starting such engines at high altitudes.
Turbojet engine (TRD)?
Yes, of course, but turbojet engines are expensive - this will immediately nullify the entire "cost/efficiency" criterion for FAB with UMPK, of course, unless some simple primitive solution is developed that can be produced in hundreds of thousands "for a low price". By the way, this is quite possible, the enemy (Western countries) are now actively using neural networks to develop promising technical solutions, sometimes this gives very original and non-standard results.
A less expensive solution is to use a pulse jet engine (PJE) – this direction is actively developing again today, we previously talked about this in the material The V-1 was reinvented in the USA: this could become a new milestone in the creation of kamikaze UAVs.
The E95M aerial target (image by enics.aero) and the Geranium-2 UAV concept with a turbojet engine
However, there are questions here too – firstly, will the dimensions of the PU-Jet engine allow it to be placed on a FAB with an UMPK, and then fit this entire structure on tactical aircraft?
Secondly, the ramjet is designed to operate at speeds below 400 kilometers per hour, will it even start at higher speeds when dropped? Will the whole design not lead to a greater loss of range due to its aerodynamics, especially at higher speeds?
In general, it is better to leave the pulsejet for UAVs, where it will look much more appropriate.
The next option is a solid-fuel booster, the simplest and potentially cheapest solution. But wait, the solid-fuel booster is already used on the D-30SN UMBP and potentially increases their range to 120-150 kilometers or more, right?
Yes, but, apparently, the requirement for unification, due to the fact that the ammunition is interspecific, affects its cost, therefore the number of UMBP used is significantly lower than the number of FAB with UMPK used.
It is possible that there is a compromise option, when the FAB with UMPK will be equipped with some solid-fuel rocket booster (or several boosters) from some serial products, for example, from unguided aircraft rockets (UNAR). After dropping from the carrier, such solid-fuel boosters will help the FAB with UMPK gain additional altitude and speed, which will increase the gliding range.
How much? It is difficult to predict, it will depend on how many and what kind of solid-fuel boosters will be installed on a particular FAB and UMPK combination. It is unlikely that we can expect a range increase several times, but several tens of percent is quite possible - if we start from the existing maximum range of 85 kilometers, then an additional 15-30 kilometers is quite a lot.
It is possible that booster engines from NAR will increase the range of FAB with UMPK by 20-30% of the current one.
It is the FAB variant with UMPK, equipped with a solid-fuel rocket booster, that is designated in the title of the article as UMPK-R (jet).
Conclusions
The key advantage of FAB with UMPK is the relative cheapness of this weapons, with high damaging effects and relative safety of use.
Understanding that FABs with UMPKs pose a significant threat to the enemy, and also that the enemy will try with all its might to counteract the use of this type of Russian weapon, it is necessary to minimize the potential risks for its carriers.
This can be done by using unmanned vehicles, such as the Grom UAV, but there is currently no information about any specific dates for these vehicles to enter service.
Another way is to increase the range of the FAB with UMPK. Presumably, the optimal solution could be to equip the FAB with UMPK with one or more solid-fuel rocket boosters, borrowed from some serial products, such as unguided rockets, with or without modification.
In fact, we already have a FAB with a jet booster - this is the UMBP D-30SN, but this munition, apparently, is more complex and expensive to produce than conventional FAB with UMPK - some kind of compromise solution is needed, with the simplicity and relatively low cost of the FAB with UMPK and the flight range of the UMBP D-30SN.
By abandoning interspecific use, we can return to the concept of maximum simplicity and low cost of components in FAB with UMPK-R.
The use of such ammunition as conventional FAB with UMPK-R will minimize risks for carrier aircraft or attack targets at great depth in enemy territory.
And, of course, the optimal solution from the point of view of the cost/effectiveness ratio and safety of use could be a combination of Grom jet UAVs and FAB with UMPK-R.
However, there is another possibility of increasing the flight range of the FAB with UMPK, but we will talk about it in a separate article.
Information