Sukhoi-Gulfstream S-21

The 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 small supersonic business aircraft, code named the S-21. Doubts about the market for supersonic business travel weakened commitment and delays mounted, Gulfstream eventually dissolved the partnership, and Sukhoi carried on alone. The design called for sustained cruise at Mach 2 and above, three Aviadvigatel D-21A1 turbofans, a crew of two with six to ten passengers, a wing that swept from 32 to 68 degrees and a range of about 7,400 km at Mach 0.95. As of 2012 the project had received no funding for the 2013 to 2025 development period and appeared to be cancelled.