Rumer was arrested on the Arbat Street in April 1938 as an accomplice of the "public enemy", Landau, when he was going to a birthday party. One of his brothers was jailed earlier on an unrelated case as part of Stalin's purges. Landau was arrested too, but released after one year owing to the extraordinary efforts of Pyotr Kapitsa. While in jail Rumer first worked on plane flutter and wobble problems in a sharashka situated at an Omsk suburb. Later in 1946 he was transferred to Taganrog. There he worked on a project of a new transport aircraft, which was headed by Robert Bartini.