The Russian Air Force’s sole regiment operating Su-57 fifth generation fighters has intensified operations in the Ukrainian theatre, and from April 15 to May 15 was reported by Ukrainian sources to have conducted more than six cruise missile strikes. This followed a report in late February that one of the aircraft conducted a strike against Ukrainian targets in the disputed Luhansk region. The Kh-59MK2 radar evading cruise missile has reportedly been used in the majority of these operations. The missile class was designed as the fighter’s primary air to ground armament, and is optimised for neutralising small hardened targets at long ranges of close to 300km. The missile uses a 320kg penetrating warhead, but can also be equipped with a smaller pellet warhead designed to affect targets over a wider area. The new missile class has short fins and can be carried in the aircraft’s internal weapons bays. Su-57s have reportedly typically been escorted by Su-35 fighters on their strike missions, although this remains unconfirmed.
Twenty-two Su-57s are currently reported to be in service, forming less than full strength regiment, with 12 delivered in 2023 up from six in 2022. Deliveries for 2024 are expected to rise to over 20 airframes, with the goal of forming three full regiments each of 24 aircraft some time in 2027. These delivery rates will make the Su-57’s production scale by far the greatest of any Russian fighter class, although still well below the Chinese J-20 at over 100 and the American F-35 at over 130. Since the participation of the Su-57 fifth generation fighter in the Russian-Ukrainian War was first reported in March 2022, a number of reports have emerged regarding the roles it has fulfilled. The aircraft was initially reported to be engaging in strike and later air defence suppression missions. The initial report of Su-57s being deployed for air to air combat was supported by a later report in January 2023 by the British Defence Ministry that the fighters were “launching long range air to surface or air to air missiles into Ukraine,” with the fighters reports to have been involved in operations “since at least June 2022.”