Sukhoi No. 135 in Kharkiv, Ukraine. However, Sukhoi was not satisfied with its location, since it was isolated from the scientific pole of Moscow. Sukhoi later relocated the bureau to the aerodrome of Podmoskovye in Moscow, completing half of the relocation by 1940. Sukhoi encountered another issue: the bureau had no production line in Moscow, thus making it useless as Sukhoi had nothing to do. During the German invasion of the Soviet Union in World War II, the Su-2 needed a successor as it was proved obsolete and under-armed against German aircraft, with 222 aircraft destroyed in total. Sukhoi and his
Sukhoi Su-15 the Su-15 was abruptly retired from the new Russian Air Force in 1993 to comply with the Treaty on Conventional Armed Forces in Europe. Most were hastily scrapped in favour of more advanced interceptors, including the Su-27 and MiG-31, but some are in reserve storage for emergency use. In Ukraine, the last Su-15s (at Kramatorsk and Belbek) were withdrawn from use in 1996. Some Western reports indicate that the Su-15TM was also designated Su-21 and the Su-15UM Su-21U. These reports are apparently incorrect. Designation Su-21 was reserved for Su-17M4 but never used. Sukhoi Su-15 The Sukhoi Su-15 (NATO reporting name: