New Sukhoi Fighter Design Unveiled at MAKS

 - July 20, 2021, 1:14 PM
The LTS is seen during its unveiling ceremony at MAKS on July 20. (Photo: still from Rostec video)

Rostec and its United Aircraft Corp. (UAC) division have unveiled a new stealthy, lightweight fighter design at the MAKS 2021 show being held this week at Zhukovsky in the Moscow suburbs. The aircraft is referred to as the LTS “Checkmate” and is a product of the Sukhoi design bureau. It is marked with the registration “RF-0075” and the Bort (side number) “Blue 75,” suggesting that the type could be designated Su-75, or have the design bureau designation T-75. Whether the article on display is a full-scale mockup or a test article is open to question. However, Rostec claims the LTS is ready for flight-test.

Shortly before the show, Rostec released an English-language teaser video that gave little in the way of detail about the aircraft, but alluded to the fact that the Checkmate is aimed at the export market, with Argentina, India, the UAE, and Vietnam highlighted. The inclusion of the UAE is notable: at the IDEX show held in Abu Dhabi in February 2017, the UAE and Russia announced an agreement on industrial cooperation on defense projects, including the development of a light fighter. It is unclear if the VKS (Russian aerospace forces) have a requirement for this class of aircraft.

UAC also shared on social media some long-range photographs of the aircraft being towed under black tarpaulins to a dedicated closed display hall. It was kept under wraps pending a presentation to Russian President Vladimir Putin by Yuri Slyusar, UAC president, on the show’s July 20 opening day.

The LTS is a stealthy, single-engine aircraft that is considerably smaller and lighter than the Su-57 “Felon,” although there are some similarities, such as the shape of the cockpit canopy. In terms of configuration, the Checkmate bears some resemblance to a Northrop multi-role fighter design from the early 1990s. It has a cropped delta wing, widely-splayed tail fins, and dispenses with horizontal stabilizers. The moveable fins act as ruddervators, providing control in both pitch and yaw axes, while the sole engine has a multi-axis thrust-vectoring nozzle.

Perhaps the most striking feature is the intake, an underslung chin inlet that wraps around the lower fuselage but with a flat underside, reminiscent of the intake of the X-32, Boeing’s unsuccessful competitor in the Joint Strike Fighter program. Slyusar commented that a two-seat version and an unmanned derivative are being considered.

Either side of the forward fuselage are weapon bays for two short-range air-to-air missiles, while three longer-range weapons can be carried in the lower bay. A gun pack can be mounted in the main weapon bay, with the gun itself protruding below the fuselage. As with the Lockheed Martin F-35, the LTS is expected to be able to carry weapons on external pylons for non-stealthy operations. Maximum combat load is 7.4 tonnes, including a range of air-to-surface weaponry.

Mtow is believed to be around 18 tonnes. The aircraft is advertised as being Mach 1.8-capable and range without external fuel is quoted as 2,800 km. It is intended to supercruise—fly supersonically without the use of afterburner—and is rated for 8G maneuvering. Its thrust-vectoring engine and aerodynamic configuration would bestow a degree of super-maneuverability on the type. The powerplant appears to be the NPO Saturn Izdeliye 30 engine, which is in development to power the definitive production version of the Su-57 twinjet.

The LTS has an open systems architecture, and incorporates an automated logistics system known as Matreshka, similar in scope to the F-35's ALIS/ODIN systems. Artificial intelligence technology is employed to provide a self-checking function of the aircraft to reduce pilot workload. The aircraft is intended to feature an AESA radar, advanced networking communications, and a powerful defensive electronics suite. The cockpit features a wide-area display and employs voice-control technology.