British Ministry of Defense noted in the intelligence report that approximately since June 2022, russia’s Armed Forces have used their Su-57 fighters in the war against Ukraine, which russians themselves call these jets "5th generation fighters", although the Su-57 is the 4++ generation aircraft.

It is stated in the report that at least 5 Su-57 aircraft are stationed at the airfield of the 929th test center of russia’s Ministry of Defense in Akhtubinsk. And that the use of the Su-57 was limited to firing air-to-air and air-to-ground missiles from russian airspace at objects on the territory (or in the airspace) of Ukraine.
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In fact, there is evidence that russians started using their Su-57s in the war against Ukraine even before June 2022.

For example, in mid-April 2022, Defense Express, citing its own sources, reported about two cases when the invaders applied these fighter jets: the 4++ generation Su-57 hit objects in Kirovohrad oblast and the territory of the Odesa seaport with Soviet Kh-59 missiles.

However, before the full-scale invasion, Kremlin propaganda talked about the development of the latest Kh-69 stealth missile, which is essentially a rebranding of the Kh-59MK2, specifically for the Su-57. And in August 2022, russian military-industrial complex presented the "non-existent" Kh-69 for the second time, and without much practical results. Although in open sources you can find the statement that in theory the Su-57 could carry as many as four X-69s in the fuselage compartment.

In turn, The Drive article assumes that russians can also use long-range missiles of the R-37M type with a declared range of up to 400 km from their Su-57s to try to "hunt down" targets in the airspace of Ukraine. The same as russians do it using their MiG-31BM.
It seems that russians themselves are still not completely confident in their Su-57, as they keep these aircraft not in the formation units, but in the "experimental" 929th test center. Although Kremlin propaganda claims that in 2022, russia’s Air Forces received as many as six aircraft of this type, reaching the overall number of serial Su-57s up to 10 units.

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