Russian culture jet Tupolev Tu-144 by Alexei Tupolev, MiG fighter aircraft series by Artem Mikoyan and Mikhail Gurevich, and Su series by Pavel Sukhoi and his followers. MiG-15 is the world's most produced jet aircraft in history, while MiG-21 is most produced supersonic aircraft. During World War II era Bereznyak-Isayev BI-1 was introduced as the first rocket-powered fighter aircraft, and Ilyushin Il-2 bomber became the most produced military aircraft in history. Polikarpov Po-2 "Kukuruznik" is the world's most produced biplane, and Mil Mi-8 is the most produced helicopter. Famous Russian battle tanks include T-34, the best tank design of World War II,
Sukhoi-Gulfstream S-21 speeds. As of 2012, the project had not received any funding for the 2013-2025 development period and appeared to be cancelled. Sukhoi-Gulfstream S-21 Sukhoi-Gulfstream S-21 was a projected Russian-American supersonic business jet. In the early 1990s, Gulfstream Aerospace and the Sukhoi Design Bureau began a joint effort to develop a supersonic small business jet, code named the S-21. Due to questionable market demand for commercial supersonic air travel, commitment to the project weakened and delays mounted. Gulfstream eventually dissolved the partnership, although Sukhoi continued work on the S-21. The S-21 would be capable of sustained cruise at Mach 2+ and