The upcoming ‘Second Stage’ engine for the Russian Su-57 fighter jet could be classified as 5+ generation, due to its increased thrust over current fifth-generation fighter aircraft engines.
“I would even say that this (Second stage engine) is the 5+ generation, slightly ahead of the 5th generation, because the specific characteristics of this engine correspond to this generation. The main thing is specific thrust, specific consumption and specific gravity, “explained Yevgeny Marchukov, general designer - director of OKB, - a branch of United Engine Corporation (UEC) which is developing the engine.
“No other engine in the world produces such specific thrust. Otherwise, it makes no sense (to create such powerful aircraft engines. Its life-span is 30-50 years," said Yevgeny Marchukov in an interview with the Zvezda TV channel of the Russian Ministry of Defense.
This is the first time a senior technical head of the project has spoken about the engine performance characteristics, though the exact numbers remain a secret. If the general-director’s words are to be interpreted, it means the second stage engine could be more powerful than P &W F-135 engine that powers the F-35 jet which is the only fifth generation fighter aircraft in the world operational with several countries.
Videos from the Zvezda TV channel report show an engine on a test bench undergoing static tests. The thrust vectoring nozzle of the engine can be clearly discerned. That the engine is on a test bench indicates that the powerplant is still under development and may be some years before it is qualified to fly on the Su-57.
Currently, prototype of the Su-57 has been photographed flying with the AL-41 FP engine derived from the Su-35. A test aircraft has also been seen flying with AL-41 engine in one bay and the Second Stage engine in another.
The Su-57 has entered serial production with the first production versions fitted with the AL-41FP engines. These aircraft are expected to enter Russian air force service by 2022.