The Soviet Union was invaded by Nazi Germany on 22 June 1941, and Stalin was transferred to the front in August 1941 and given the surname Ivanov in an attempt to conceal his identity. As the son of Stalin, he flew in combat rarely, and when he did he was accompanied by a formation. Vasily took part in 29 combat missions, and is said to have shot down two enemy aircraft. As the son of the Soviet leader, Vasily was hated by most of his colleagues, who felt he was an informant to his father. In the spring of 1942 he was sent back to Moscow, and given a role inspecting the conditions of the air force, and mainly stayed in Moscow for the rest of the war. Bored in this role, Vasily was in trouble after a 4 April 1943 incident where he had explosives dropped into the Moskva River, injuring himself and killing the flight engineer.