Flight trials of the second prototype of Sukhoi's fifth-generation T-50 fighter aircraft are due before the end of the year, Sukhoi holding CEO Mikhail Pogosyan said on Monday.
The first prototype of the aircraft made its maiden flight in late January and has conducted 40 in total, Pogosyan said.
"The flight trial program is moving ahead faster than we expected," Pogosyan said.
He said talks with India's Hindustan Aeronautics Limited (HAL) on the joint development of the fifth-generation fighter aircraft are due to conclude before the end of the year.
Earlier reports said an agreement would be signed in December.
The new warplane is expected to enter service with the Russian Air Force in 2015.