The Russian Air Force has deployed a Su-57 fifth generation fighter for strike missions against Ukrainian targets in the disputed Luhansk region, with unconfirmed reports indicating that the aircraft entered Ukrainian airspace during the operation. The aircraft reportedly used Kh-59MK2 cruise missiles to strike targets at beyond visual ranges. A number of aspects of the new report remain questionable, however, including how it was known class of missiles the aircraft utilised, and why the Su-57 would enter Ukraine’s airspace when the Kh-69 was able to engage targets across Luhansk from deep inside Russia. Strikes using the Kh-59MK2 on February 7-8 were the first to be confirmed by Ukrainian sources, with the missile class having previously been combat tested in Syria and being well optimised for neutralising small hardened targets. Despite having a long 300km engagement range, the missile is compact enough to fit inside the aircraft’s internal weapons bays, allowing Su-57s to maintain their reduced radar cross sections. No other fifth generation fighter class is known to be capable of internally carrying a similar missile class.
Two battalions making up a single regiment currently deploy Su-57 fighters, with 22 of the aircraft having entered service by the end of 2023 after 12 were delivered that year – up from just six deliveries in 2022. 20 or more of the aircraft are expected to be delivered in 2024, bringing the class’ production to a scale exceeding that of any other Russian fighter class, or any fighter in the world other than the American F-35 and Chinese J-10C, J-16 and J-20. With a flyaway cost of approximately $35 million per aircraft, depending on rouble exchange rates, this makes the Su-57 less than half as expensive to procure as the world’s only other two fifth generation fighters in production the Chinese J-20 and the much lighter single engine F-35. The aircraft was initially intended to form the backbone of the Russian Air Force by the mid-2020s, with over 200 set to be fielded by 2025, although serious delays to the program means that 2024 will be its first year of high rate production, rather than 2018 as originally envisaged. A new class of glide bomb developed specifically for the aircraft, the PBK-500U Drel, is scheduled to enter serial production in 2024, which could significantly increase the likelihood of the aircraft being deployed deeper within Ukrainian airspace to engage targets from closer ranges as part of combat testing.