Aeroflot Flight 721 was a scheduled domestic passenger flight between Moscow and Yuzhno-Sakhalinsk in the Russian SFSR. On Wednesday, 2 September 1964, the aircraft flying this route, an Ilyushin Il-18V, crashed into the side of a hill on approach to Yuzhno-Sakhalinsk, killing 87 of the 93 people on board. At the time of the accident, it was the deadliest Il-18 crash and the deadliest aviation accident on Russian soil.
