The US and Europe are working to find replacements for the ammunition of Ukraine’s S-300 and R-27 missiles

The United States is collaborating with Ukraine on the design and construction of a replacement for the S-300 surface-to-air missile system and the R-27 air-to-air missile.

«Meanwhile, with help from several European companies, the United States is working with Ukraine to design and build a substitute for the S-300 surface-to-air missile system and the R-27 air-to-air missile», stated U.S. Secretary of Defense Lloyd J. Austin III during his opening remarks at the 24th meeting of the Ukraine Defense Contact Group.

Austin did not go into detail about the characteristics that such substitutes will have.

Ammunition for S-300 systems

According to the Ukrainian website Militarnyi, Ukraine had approximately 25-30 S-300PT/PS divisions in various states of readiness. Even after the losses suffered over two and a half years of war, it remains a numerically significant air defense system. However, the main problem Ukraine faces is a shortage of ammunition, as these systems use the 5V55 missile, which is no longer manufactured and has extremely limited availability on the global market.

Despite advances in modernization and mastery of technologies for the domestic production of key components, such as 5V55 missiles and the replacement of original 48D6 solid fuel engines (many of which have expired) with a domestically developed one, Ukraine still faces challenges in mastering the entire technical cycle and large-scale production of these systems remains a goal to be achieved.

I see two potential solutions to resupply Ukraine’s S-300PT/PS systems with ammunition. One would be to make Western-made surface-to-air missiles compatible so that they can be fired from Ukrainian S-300 PT/PS systems. Given the successful integration of American and European missiles into Ukrainian MiG-29s, it might be feasible to integrate ASTER missiles into S-300 TEL (Transport Erector Launcher) vehicles.

Alternatively, Western defense industries could assist Ukraine in producing critical components to restore its remaining S-300 batteries. This could even involve manufacturing copies of 5V55 missiles or their engines for subsequent transfer to Ukraine.

Replacement of R-27

The Vympel R-27 (NATO code name is AA-10 Alamo) is a family of air-to-air missiles developed by the Soviet Union at the end of the Cold War.

The R-27 is produced in infrared-guided (R-27T, R-27ET), semi-active radar-guided (R-27R, R-27ER), and active radar-guided (R-27EA) versions. Missiles of the R-27 family are produced by both Russian and Ukrainian manufacturers. The R-27 is the main medium-range air-to-air missile used by Ukrainian Mikoyan MiG-29 and Sukhoi Su-27 fighters, but it is already technologically quite outdated compared to the latest generations of missiles, which have more accurate guidance systems, longer ranges and superior maneuverability capabilities.

There are few cost-effective, short-term solutions beyond adapting Ukrainian fighters to use Western missiles. Given their availability and compatibility with incoming F-16s, AMRAAMs appear to be the most suitable replacement for R-27s. While Ukrainian Su-27s and MiG-29s may not fully leverage the AMRAAM’s advanced capabilities, their integration would significantly enhance Ukraine’s air defenses.