Russia regularly uses its strategic aviation to attack cities and infrastructure across Ukraine.Ukraine handed over Tu-160 supersonic heavy bombers in 1999 as part of a larger debt payment for Russian gas. The journalists identified the planes by comparing their old serial numbers in archives and aviation registries.RFE/RL was also able to identify some pilots flying these planes against Ukraine, like Oleg Skytskyi, a serviceman of the 22nd Aviation Division, which Ukraine's military intelligence (HUR) says is "responsible for numerous victims and destruction in Ukraine," one of them likely being launching a missile that killed an RFE/RL journalist in Kyiv on April 28, 2022.In the 1999 arms transfer, Kyiv transferred to Moscow eight Tu-160 and three Tu-95MS heavy bombers, as well as 575 Kh-55 cruise missiles, with Russia writing off $275 million in gas debt, 10% of the assets' real value.