When this bird is expected to take a leap in the air?

On 28 of February 2009 Mikhail pogosyan announced that the airframe for the aircraft was almost finished and that the first prototype should be ready by August 2009.On 20 August 2009, Sukhoi General Director Mikhail Pogosyan said that the first flight would be by year end. Konstantin Makiyenko, deputy head of the Moscow-based Centre for Analysis of Strategies and Technologies said that "even with delays", the plane would likely make its first flight by January or February,

adding that there could be at least 10 years between the first flight and commercial production & On same occasion Russian Air Force Chief Alexander Zelin said that there were problems with the engines

and research was continuing.