Projected originally as a joint program by Sukhoi and Gulfstream Aerospace; separate studies for aircraft of this type started by Sukhoi in 1987 and by Gulfstream in 1988. Design submitted by Sukhoi in October 1991. Gulfstream withdrew from program in 1992. First flight originally scheduled for 1994. Series production was planned in 2000 with demand forecast at 150 aircraft.
Model of Sukhoi S-21 six/ten passenger supersonic transport from the USSR-Russian Aviation and Space Collectibles web site.
Text source: Jackson, Paul editor. Jane's All the World's Aircraft 1995-96 Jane's Information Group Limited 1995
Source: http://www.ussr-airspace.com/index.php?main_page=product_info&cPath=28_39_38_97&products_id=720
Model of Sukhoi S-21 six/ten passenger supersonic transport from the USSR-Russian Aviation and Space Collectibles web site.
Text source: Jackson, Paul editor. Jane's All the World's Aircraft 1995-96 Jane's Information Group Limited 1995
Source: http://www.ussr-airspace.com/index.php?main_page=product_info&cPath=28_39_38_97&products_id=720