Listen to the unique 'howl' of Russia's new stealth fighter jet

The Sukhoi Su-57's engines generate a peculiar noise, a sort of "howl."
The Su-57 is Russia's fifth-generation fighter, and there are plans to upgrade its engine and other components.

We have already talked about the peculiar engine sound of the Su-57 Felon, Russia's 5th-generation aircraft earlier this year, commenting a video of a low level flyby of four jets.

The engine that generates that creepy high-pitched ringing noise is the NPO Saturn AL-41F-1, derived from the one used by the Su-35.

It's an interim variable-bypass ratio turbofan engine rated at approximately 88.3 KN (19,842 lb st) of dry thrust and 142.2kN (31,967 lb st) with afterburning.

A few more videos filmed during the 2021 Victory Parade over Moscow have circulated online. You'll probably find a few more ones around, but the following two are extremely cool and worth being posted.

The first one, was actually filmed on June 24, 2020, in the city of Zhukovsky, Moscow region, that hosted the grand opening of the monument to the Hero of the Soviet Union Igor Petrovich Volk, Honored Test Pilot of the USSR, pilot-cosmonaut of the USSR, commander of the group of test pilots "Buran," president of the international association "Earth and Cosmonautics," an honorary resident of Zhukovsky.

Four Su-57s flew over Zhukovsky to celebrate the opening of the bust of the legendary pilot.

Here's what we wrote about the current engine and the program to replace it:

As reported in detail in a previous article, the current AL-41F-1 engine, considered underpowered for the aircraft, is only an interim power plant until the final engine is ready. The latter, known as Izdeliye 30 (literally Product 30) will be supposedly more efficient than previous designs, giving to the jet a top speed in excess of Mach 2 and a supercruise capability at Mach 1.3, and features 3d thrust vectoring. The Izdeliye 30 begun flight testing in 2017 and is expected to be ready by 2025. This means that serial production of the Su-57 may have to keep using the AL-51F-1 for the first examples and retrofit them when the new engine becomes available. The S-duct air inlet doesn't cover the entire engine face, as done for the F-22 and F-35; the problem is mitigated by the air intake screen (which then have a double function other than FOD prevention) and a radar blocker in front of the engine fan, similar to the one used by the F/A-18 Super Hornet.

A new engine was specifically developed for the Su-57, known as Izdeliye 30 (literally Product 30), but, since the engine is not yet ready for production and tested only on an earlier prototype, T-50S-2 is still using the Saturn AL-41F-1. Production of the Product 30 engine should begin in 2022, with the first serial deliveries of the Product 30-equipped Su-57 in 2023. Dealing with the engine, the Felon was recently showcased in a video for the 100th anniversary of the Chkalov State Flight Test Center, where the radar blockers in the engines' air intakes were allegedly exposed for the first time. The Su-57 uses a S-duct air inlet which does not cover the entire engine faces, as done for the F-22 Raptor and the F-35 Lightning II, leaving it exposed to radar signal reflection. The problem was said to be mitigated by a radar blocker that, however, was never clearly seen on any of the 11 prototypes or the first two serial aircraft.

More recently, Russian State Agency TASS reported that an upgraded and modernized version of the Su-57 is to begin serial production as of 2025, and among the improvements, there will be the incorporation of the Izdeliye 30 engine along with the upgrade of the cockpit to unify the production of the Su-57 and the Su-75 Checkmate that, along with the same engine, will have an identical cockpit layout as the one of the Felon.

Read the original article on Business Insider