A short highlight of this article for all lazy readers
1)the fourth aircraft is the first example to be equipped with the N036 Belka (squirrel) radar during the construction process at Komsomolsk-on-amur.
2)On the fuselage sides of the t-50-4, just aft of the cockpit, two sensors are mounted to serve the 101Ks-U ultra-violet missile approach warning system (MaWs).
3)together with two further 101Ks-U sensors fitted previously (on the third example) under the nose and atop the tail boom, the system provides observation of airspace all around the aircraft.
4)surprisingly, the ball for the 101Ks-O (oborona, defence) active electro-optical jamming system, which on the previous aircraft
was mounted on the fuselage spine just aft of the cockpit, disappeared from the t-50-4 airframe. in its place appeared on the t-50-4 a small blade antenna and two small box-shaped antennae at its sides; these are presumed to be communications aerials.
5)the head of tactical Missiles Corporation, Boris Obnosov, confirmed in November 2012 that the t-50 would perform its first missile launches 'very soon'.