Sukhoi/HAL FGFA Su-57, the foundation for FGFA's development, among many things the degree of low observability allowed by the design being the biggest of issues. However, Indian officials did not rule out the possibility of relaunching the FGFA project once the Su-57 is fully introduced into the Russian air force, or later acquiring the fully developed platform. On 19 August 2018, it was reported that the FGFA program was not cancelled; the President of the Russian United Aircraft Corporation said that is was just rumours, and that India was still working with Sukhoi on the FGFA program. Although there is no reliable
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