In a milestone achievement, Sukhoi’s PAK FA fighter has broken the sound barrier during flight testing.

The first supersonic flight took place last week at the test range near Komsomolsk-on-Amur in Siberia. Sukhoi engineers deemed it a success. Although the top speed of the PAK FA has not officially been disclosed, it is expected to be able to supercruise (fly faster than the speed of sound without afterburner) and have a top speed of more than Mach 2.

Two prototypes are now in flight testing, with the T-50 first flying in January 2010. The second prototype took to the air earlier this month. A third airframe is being used for load testing while another two aircraft with radar and weapons systems will be added to the test programme.

Flight testing will continue until next year before the Russian ministry of defence acquires ten pre-production aircraft in 2013 for operational evaluation. Series production of the PAK FA will commence in 2015.

The PAK FA is intended to replace the MiG-29 and Su-27 in Russian Air Force service and will also serve as the basis for the Sukhoi/Hindustan Aeronautics Limited (HAL) Fifth Generation Fighter Aircraft (FGFA) project being jointly developed with India.

Mikhail Pogosyan, director of Sukhoi, estimates a market for a thousand PAK FA aircraft over the next four decades. Two hundred will be produced for India, two hundred for Russia and the rest will be for export.

The PAK FA will be the first all-new warplane to enter Russian Air Force service since the collapse of the Soviet Union in 1991.