Sukhoi Su-38 no users have yet expressed interest in the aircraft, the project is currently proceeding at a low pace. Sukhoi Su-38 The Su-38L is a Russian agricultural aircraft, the first aircraft of this type to be designed and built by the Sukhoi Design Bureau civil aircraft section (Sukhoi Civil Aircraft (CJSC)). Design originally began in 1993 as a development of the Sukhoi Su-29 aerobatic aircraft. Development was suspended due to economic problems, and when restarted in 1998, the aircraft was redesigned, reducing the aircraft's size and replacing the originally planned M-14 radial engine with a LOM Praha 337S inline engine. The
Sukhoi-Gulfstream S-21 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 much research and development has gone into the management of the troublesome transonic effects phenomena associated with near Mach 1 air