Sukhoi Su-57 the Su-27. Extendible refueling probe is available to further increase its range. In the Su-57's design, Sukhoi addressed what it considered to be the F-22's limitations, such as its inability to use thrust vectoring to induce roll and yaw moments and a lack of space for weapons bays between the engines, and complications for stall recovery if thrust vectoring fails. The Su-57 will be the first operational aircraft in Russian Air Force service to use stealth technology. Similar to other stealth fighters such as the F-22, the airframe incorporates planform edge alignment to reduce its radar cross-section (RCS); the leading
Sukhoi Su-57 produced, and some believe it to be an implicit announcement of the project's cancellation. The slowing of procurement could be because of the current slow growth of the Russian economy, while the future patches' procurement are for an unknown future; the Russian military could be waiting for the more powerful Saturn izdeliye 30 engine to be ready for serial production. On 22 August 2018, during the International Military-Technical Forum «ARMY-2018», the Russian Ministry of Defence and the JSC Sukhoi signed the first contract for delivery of two serial Su-57s. The contract should be finalized between 2018 and 2020. The prototype's