Step (also Olovyannaya) is an air base in Chita, Russia located 14 km northwest of Yasnogorsk. It is a large air base with two revetment areas and numerous military fortifications. It is near an SS-11 missile field that was dismantled in the mid-1990s. The 849th Assault Aviation Regiment, part of the 253rd Assault Aviation Division, was stationed at Step up until 1956. Units stationed at Step/Olovyannaya include: The base appears to have been closed after a boiler room fire in December 2009. Thereafter, the base was reopened and the 266th Independent Shturmovik Aviation Regiment was reformed with at least two squadrons of Sukhoi-25s in 2019. The regiment by this time had been shifted into the Eastern Military District's 11th Air and Air Defence Forces Army.