The Sukhoi Su-37 was a single-seat twin-engine aircraft designed by the Sukhoi Design Bureau which served as a technology demonstrator. It met the need to enhance pilot control of the Su-27M, a further development of the Su-27. The sole example built was originally the eleventh Su-27M (T10M-11) built by the Komsomolsk-on-Amur Aircraft Production Association before having thrust-vectoring nozzles installed. It also had 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.