Two of Russia’s Premier Air Superiority Fighters Lost as Su-35s Crash Near Frontlines

Two Russian Aerospace Forces Su-35S air superiority fighters collided in mid-air over Russia’s Kursk Region on September 7, killing one pilot, after the aircraft were reportedly supporting combat operations in the Ukrainian theatre. The collision highlights an often-overlooked vulnerability of advanced combat aircraft, namely that even highly sophisticated fighters remain dependent upon pilots maintaining precise positional awareness when operating together. A mid-air collision can occur because of a failure in visual separation, navigation, communications, human factors or other technical circumstances, and it would be premature to attribute this particular incident to any one cause before an investigation is completed.

Su-35s have engaged Ukrainian fighters several dozen times since the outbreak of full scale hostilities in 2022, and have achieved over a dozen confirmed air-to-air kills primarily against MiG-29 and Su-27 fighters. In late August a Su-35 was flown on a rare deep penetration strike into Ukrainian-controlled territory in the Sumy region, flying over the town of Uhroidy and launching a Kh-59/69 guided missile towards Sumy City. This represented a notable departure from the operating patterns that have characterised much of the war, and indicate a potential shift in doctrine in response to a weakening of adversary air defences. 

The Russian Aerospace Forces in late August received a new batch of Su-35s, following the delivery of the first and second batches announced in April and May. The Su-35 is one of four fighter types currently being procured by the Russian Armed Forces, alongside the Su-30SM2 and Su-34M, which are derivatives of the same Soviet Su-27 Flanker design, and the new Su-57 fifth generation fighter. The number of aircraft ordered has far exceeded initial expectations for the program, primarily due to major delays to the Su-57’s development. 

The Russian Aerospace Forces are projected to receive the aircraft at a significantly slower rate in 2026 and 2027, as the production capacity  is focused on meeting large orders from Iran. The factory was reported in early July to have completed the production of 20 of the fighters for the Iranian Air Force, with 28 additional fighters having been ordered. Further followup orders by Iran, and possible sales to other clients most notably North Korea, could further reduce industry’s ability to supply Russian forces. Su-35 losses in the Ukrainian theatre have nevertheless remained minimal, particularly compared to the Su-30SM and Su-34 fighters which are better optimised for and more widely used in strike operations, meaning that the need for further deliveries remains more limited.