Russian flat variable-geometry nozzle.

Russia started practical work on the thrust vector control from late 80's. Su-27s were widely used as flying labs for testing new aircraft and systems, The flying lab derived from the T10-26 was used to test the asymmetric swivelling nozzle. In 1990, the T10U-5 combat trainer left engine was fitted with a flat variable-geometry nozzle. The results of those and other tests have been used in designing new versions of the fighter and prospective combat aircraft.

The team was lead by Mikhail Pogosyan (General Director of Sukhoi Aviation)

Mikhail Pogosyan in the video say's huge technology advancement were made to develop a 5th generation aircraft, Not all the solutions were implemented on the flying laboratory which we flew with a flat nozzle, During the test we monitored the performance and manageability of the system.

Flat nozzle makes it possible to substantially reduce the infrared signature of the exhaust plume of the aircraft which is very critical for the protection of the aircraft against missiles with thermal homing seekers.

We got very good result, which shows how to reduced the level of infrared radiation.