When did the campaign of political  repression that Mikhail Demichev was arrested during occur?
Mikhail Demichev Mikhail Demichev (1885 – November 19, 1937) was a Soviet Komdiv (division commander). He fought in the Imperial Russian Army in World War I before going over to the Bolsheviks in the subsequent civil war. He was a recipient of the Order of the Red Banner. During the Great Purge, he was arrested on August 9, 1937 and later executed. After the death of Joseph Stalin, he was rehabilitated in 1956.
Dymshits–Kuznetsov hijacking affair The Dymshits–Kuznetsov aircraft hijacking affair, also known as The First Leningrad Trial or Operation Wedding (Russian: Ленинградское самолётное дело , or Дело группы Дымшица-Кузнецова) (Leningrad Process), was an attempt to steal a civilian aircraft on 15 June 1970 by a group of 16 Soviet refuseniks in order to escape to the West. Even though the attempt was unsuccessful, it was a notable event in the course of the Cold War because it drew international attention to human rights violations in the USSR and resulted in the temporary loosening of emigration restrictions.