The Sukhoi Su-37 was a single-seat twin-engine aircraft designed by the Sukhoi Design Bureau that served as a technology demonstrator. It allowed for the need to enhance pilot control of the Su-27M, which was a further development of the Su-27. The sole aircraft had originally been built as the eleventh Su-27M (T10M-11) by the Komsomolsk-on-Amur Aircraft Production Association before having its thrust-vectoring nozzles installed. In addition, it was modified with updated flight- and weapons-control systems. The aircraft made its maiden flight in April 1996. Throughout the flight-test program, the Su-37 demonstrated its supermanoeuvrability at air shows, performing manoeuvres such as a 360-degree somersault. The aircraft crashed in December 2002 due to structural failure. The Su-37 did not enter production; despite a report in 1998 which claimed that Sukhoi had built a second Su-37 using the twelfth Su-27M airframe, T10M-11 remained the sole prototype. Sukhoi had instead applied the aircraft's systems to the design bureau's other fighter designs.
