New versions of the Russian Su57 fifth generation stealth fighter jet are being developed one of which will be a two-seat aircraft

The Russian military will receive four Su-57 fighters this year. “The main event last year was the delivery of the first serial Su-57 in December under a contract for 76 such machines," according to the head of the United Aircraft Corporation, Yuri Slyusar was quoted as saying at a meeting with Russian President Vladimir Putin, Interfax reported.

“Development of several versions of this machine, the beginning of development work is expected this year," said Slussar said adding “and our task is to be technologically ready for this, including taking into account the new tasks that the customer has set for this machine”.

He did not specify the number and type of individual versions. However, hinting that the aircraft would be mass-produced he said, "the (production) order for these machines will be measured in hundreds."

On June 16, Deputy Prime Minister Yuri Borisov, who oversees the defence industry complex, announced that it was planned to develop a two-seater version of the Su-57 fighter in the export version. "The plans of the Ministry of Defence and the Sukhoi Design Bureau are to manufacture a two-pilot cockpit, which will expand the export demand for this model, it can create additional demand," Borisov said at the time.

The Su-57’s maiden flight took place on January 29, 2010. At the end of 2020, the Russian Armed Forces received the first serial Su-57 at the end of 2020. The Russian military has ordered 76 Su-57 fighters in 2028 under a contract signed by UAC and the Russian Ministry of Defence.

Critics argue that the Su-57 is behind time and will be staring at obsolescence by the second half of this decade when the U.S. and Europe are expected to launch their sixth-generation jets such as the NGAD (U.S.) and FCAS (Europe). UAC displayed an export version of the Su-57, designated as Su-57E at the 2019 MAKS show but that version has evinced little interest from international customers.

The Su-57’s all-important ‘second stage’ engine (also called Article 30 engine) that will provide the fighter with supersonic cruising speed is said to be still under testing despite flight tests being initiated in December 2017.

Interfrax quoted the head of ROSTEC Sergei Chemezov as saying, "sometime in 2022 the engines will be ready," put on the wing,” and within a few years we will launch their serial production." Chemezov's statement does not give hope of an early induction of the 'second stage' engine into the Su-57 program.