The rotary jet nozzle located along the axis of symmetry of the fuselage serves to control and stabilize flight. It can only redirect up and down within the vertical plane and can be adjusted from any direction.
Yuri Slyusar, who previously led the United Aircraft Corporation, noted that Checkmate will use the Izdeliye 117 engine, which will be modified for a single engine aircraft. He stated that Checkmate is aiming for its first flight in 2023, with mass production planned for 2026.
A document from the Federal Intellectual Property Service also confirms that the Checkmate model has undergone wind tunnel testing.
According to the document, the combined controls in the aircraft design enable shifting zones where unstable static instability occurs, improve handling characteristics, and reduce the drag of the aerodynamic configuration. These conclusions are supported by model calculations and wind tunnel tests, the source notes.
Checkmate was developed under the Sukhoi initiative, part of UAC. It debuted at the MAKS air show in 2021 and later showcased externally at the Dubai Airshow in 2021. The aircraft employs stealth technologies and includes an internal compartment for air to air and air to ground weapons. The fighter is described as capable of engaging six targets simultaneously, with a top speed of Mach 1.8 and a combat radius of about 3,000 kilometers.
Russian aviation experts explain that rotary nozzle engines are already used in 4++ generation aircraft such as the MiG-35, Su-30SM, Su-35, and Su-37. This engine design is said to enhance maneuverability at low speeds, enabling advanced aerobatics. The use of rotary nozzles is highlighted as a notable feature associated with Russian engine design, with observers noting dramatic flight capabilities that differ from many foreign aircraft.
The expert also points out that foreign aircraft engines generally do not feature rotary nozzles.
Retired Air Force Major General Vladimir Popov, who formerly led a federal aerospace search and rescue directorate, explains that the rotary jet engine functions as a thrust vector engine. The outlet nozzle can move both upward and downward by about 15 to 20 degrees and can deflect left or right by roughly 8 to 10 degrees. This shifting of thrust changes controllability and increases maneuverability, contributing to higher piloting safety. An aircraft with such an engine is expected to be more agile and versatile in air combat, improving its chances in missions by dodging missiles more effectively.
The general notes that while some 4++ generation aircraft use oval rotary nozzles, Checkmate is likely to feature a rectangular jet engine. He argues that a rectangular nozzle would not only enhance maneuverability but also reduce radar visibility by scattering reflected radar beams. The same principle would affect infrared tracking, as the exhaust gases disperse more readily in the surrounding air. The exhaust plume temperatures are described as ranging from 400 to 500 degrees Celsius.
The elongated exhaust outlet and the rectangular nozzle shape are said to promote better mixing with the environment, lowering the temperature gradient and delaying the guided head of an incoming missile in the infrared spectrum. This combination is expected to give Checkmate an infrared signature advantage and extend the pilot’s decision time in potential engagements.
The assessment concludes that this technology contributes to improved reaction times for both the enemy and the Checkmate crew, enhancing overall combat readiness and survivability in air operations.