Breakthrough in Aviation: Su-57 with AL-51F1 Engine to Become the Fastest Fifth-Generation Fighter

Rostec, under the current contract with the Ministry of Defense of the Russian Federation, will supply some Su-57 aircraft with the second-stage engine, also known as "Product 30" — AL-51F1.

The new engine was first presented in July 2023 under the designation AL-51F1 at a scientific and technical conference on the prospects of engine building at the Samara Technical University. In the presentation of "ODK-Kuznetsov", the second-stage engine for the Su-57 was designated as AL-51-F1 on one of the slides.

Accelerates to Over Mach 2 Without Afterburners

According to analysts and experts in the aviation industry, the AL-51F1 engine will be able to develop a nominal thrust of at least 11,000 kgf, and up to 17,000 kgf with afterburner.

The thrust-to-weight ratio of the aircraft will be more than one — 1.15-1.2 with normal take-off weight. Currently, the parameter is 1.09 with normal take-off weight and 0.97 with take-off weight with full load.

АЛ-51Ф1
Image source Военный осведомитель

Thus, in non-afterburning mode, the AL-51F1 will provide the Su-57M fighters with a sharp increase in supersonic cruising speed to 1.9 - 2.1M. Currently, this figure reaches 1.6 - 1.7M. Thanks to the power plant, the Su-57 will become the fastest fighter of its generation.

Not Only Fast, But Also Stealthy

The new engine is also well optimized to ensure stealth, it has converging-diverging nozzles with toothed flaps to reduce radar signature.

According to estimates, the thrust of the AL-51F1 is approximately 8% higher than that of its closest American competitor, the F119 engine installed on the F-22. Although its main advantage will be much less maintenance and the ability to control the thrust vector to improve maneuverability at low speeds.