Russian Su-57 fighters cause mysterious sound that frightened Moscow residents

Numerous people reported hearing the strange high-pitched ringing sound during a rehearsal of the Victory Day Parade in Moscow, while the four newest Russian Su-57 Felon fighter jets appeared in the sky.

A Moscow resident has described hearing a mysterious ‘scary’ noise in the skies above the city as ‘like something a real howl’.

The Frelon reportedly continues to suffer from developmental issues, including the production of the new turbofan engines. The initial serial production versions lack the promised new-generation engines.

Aviation experts have stressed that Su-57 Frelon is equipped with two advanced versions of an NPO Saturn AL-41F-1 interim variable-bypass ratio turbofan engine. This is a temporary measure until the Russian aviation industry is able to develop a new engine that will meet all the standards of a fifth-generation fighter.

According to the TASS, the fifth-generation Sukhoi Su-57 fighter jet is designed for destroying any type of air and surface targets. It has a supersonic cruising speed, intra-fuselage weapons, radar absorbing coating (stealth technology) and the newest set of onboard equipment.

Earlier in December 2020, Russian Defense Minister Sergei Shoigu told the Defense Ministry’s board meeting that a total of 22 Sukhoi-57 planes would be provided by the end of 2024. Under a contract concluded in 2019 a total of 76 Sukhoi-57s are to be delivered by the end of 2028.