Russia's first stealth fighter jet has had to abort a takeoff at Moscow's International Aviation and Space Show.
The T-50 did not leave the runway and was slowed by a brake parachute.
The reason for Sunday’s aborted takeoff was not immediately clear. Russian news agencies quoted air show officials as saying only that the reason was "technical."
The T-50 had been kept out of the public eye before its debut at the air show on Wednesday during a visit by Prime Minister Vladimir Putin.
The twin-engined jet is intended to match the U.S. F-22 Raptor, which entered service in 2005.
The Russian fighter still lacks new engines and state-of-the art equipment, and its serial production is only expected to begin in 2015 at the most optimistic forecast.