The TU-4 was a reverse engineered copy of the B-29. Tu-4 (Russian B29) is a Soviet piston strategic bomber that entered service in 1949 and operated until about the mid-60s. This aircraft can be safely called unique, and there are several reasons for this. Tu-4 is the first Soviet aircraft carrying nuclear weapons, that is, it can be safely called the pioneer of Russian strategic aviation. It is also an exact copy of the American B-29 bomber.