Images of the Su-57 Felon fighter's new thrust vectoring nozzle to improve stealth characteristics were shared on social media.
Russia is opting for a new design for one of Su-57's trademark features. The new nozzle with an angled shape, similar to that of U.S.-made F-22 Raptor's, is a 2D vectoring nozzle. The non-stealthy nature of circular profile 3D vectoring nozzles is the main reason behind switching to a configuration with less freedom.
Stealth characteristics have been among the main subjects of criticism on Su-57 due to exposed engine inlets, poor coating of the engines against radar waves, and non-stealthy nozzle design.
The new form's angled profile can contribute to the distortion of incoming radar waves, but stealth is a multi-layered field of optimisation for fighter jets. In addition to concealment from radars, stealth aircraft also feature reduced thermal signature, most of which is provided by the applications of coating on the engine.
Russia's other meaningful change regarding Su-57's propulsion is the switch to the AL-51F1 low-bypass turbofan engines with better supercruise performance and increased use of composite materials. The prototype with the new engine made its maiden flight in 2022.
The fighter made its combat debut in the Russo-Ukrainian war, albeit with limited use. Due to sanctions and technical difficulties, the production of Su-57 has started later than planned, with a low output.
