The Sukhoi Su-75 Checkmate (Russian: Сухой Су-75), also designated as the Light Tactical Aircraft (LTA; Russian: Легкого Тактического Самолета - ЛТС, romanized: Legkogo Takticheskogo Samoleta - LTS),[1][2] is a single-engine, stealthfighter aircraft under development by Sukhoi for export and for the Russian Aerospace Forces.[3] The Sukhoi Design Bureau also designates the aircraft as T-75.[4]
Development
A static non-flying prototype was unveiled at the 2021 MAKS air show with President of RussiaVladimir Putin in attendance. The Checkmate's maiden flight was first scheduled for 2023 and then slipped to 2024, with initial deliveries planned for 2026–2027.[5][6][7][8] The Checkmate is designed to be low cost and for export,[9] and may compete with the Lockheed Martin F-35 Lightning II and Shenyang FC-31 aircraft of the same light to medium-weight category.[10][11][12] Production is forecast to be 300 planes over 15 years.[13][14]
According to the chief executive of Rostec, Sergei Chemezov, the LTS Checkmate is expected to cost US $25–30 million each.[15]
Su-75 Checkmate development could be delayed due to international sanctions[17] on Russia caused by the Russo-Ukrainian War, and Russia could not import semiconductors[18] and high-tech machining equipment from the European Union.[19] The potential export sales also stalled because Russia cannot trade using U.S. dollars.[20]
On 16 August 2022, United Aircraft Corporation reported that they plan to build four prototypes of the Su-75 Checkmate, with flight tests planned for as early as 2024.[21]
In July 2023, analyst Maya Carlin of the Center for Security Policy expressed concerns that sanctions against Russia, due to the ongoing invasion of Ukraine had slowed or stopped the aircraft's development. In particular noted was the loss of funding from the United Arab Emirates due to sanctions, which had been sustaining the Su-75's development, as the UAE seeks instead to acquire F-35s, with potential support from Israel.[22]
On 13 November 2023 Rostec announced that preparations had begun to place the SU-75 fighter into pre production.[23]
Design
The Su-75 has a diverterless supersonic inlet (DSI), a v-tail and internal weapons bays—all features intended to reduce radar signature. The wing area appears large, which has been interpreted by correspondent David Axe to imply that Sukhoi designed the fighter to fly and engage in combat at high altitudes—40,000 ft (12,000 m) or higher.[3][24]
The angular ventral inlet, which wraps around the lower nose section, shares features with a DSI design concept first introduced[25][26] in the Boeing X-32 aircraft.[27][28][6][29] A diverterless supersonic inlet (DSI) is mechanically simple; DSI can reduce cost compared to more intricate inlet designs such as the McDonnell Douglas F-15 or Sukhoi Su-27.[30] Instead of a conventional empennage, the Su-75 has a v-tail similar to that of Northrop YF-23.[31][28] Instead of a set of elevators and a tail separately controlling pitch and yaw, a pair of combined ruddervators fulfil both roles. However, ruddervators require more sophisticated flight-control systems than conventional empennages.[31]
According to the jet's designers, the Checkmate is designed to fly with a range of up to 3,000 km (1,864 mi), carry a payload of up 7,400 kg (16,314 lb), and reach speeds of up to Mach 1.8 to 2.0.[7][32][33] The fighter will also feature an internal weapons bay with five missiles and an autocannon.[32][34]
Patents published in 2023 indicate that the initial design had been modified with changes to the fuselage sides, strakes and the air intakes to reduce radar signature. Mainly, the new design appears to have increased the lifting surface area of the airframe.[22]
Engine
Mock-up of the Checkmate's engine
The powerplant appears to be the Saturn izdeliye 30 engine which will also power the Su-57M variant.[35][4] The izdeliye 30 is designed to be 30% lower specific weight than its AL-41F1 predecessor, and up to 18% more effective, with an estimated thrust of 107.9 kN (24,300 lbf) dry and 171.7 kN (38,600 lbf) in afterburner. Once in series production, the izdeliye 30 engine will have a much longer life span than other Russian engines.[36][37]
Cockpit
Due to restrictions preventing taking cockpit photos, NBC News Matt Bodner, the first Western journalist able to see the jet in person, provided a preview without a point of view photo. According to Bodner, the cockpit layout is identical to the Su-57 with a glass cockpit with two 38 cm (15 in) main multi-functional LCD displays similar to the arrangement of the Su-35S. The cockpit has a wide-angle (30° by 22°) head-up display (HUD).[38]
Avionics
The electronic infrastructure of the Checkmate is all open-architecture and makes use of "Matryoska" diagnostics systems that are mostly on-board.[12] According to Russian news blog Top War, the prototype Su-75 is built with an active phased array radar. According to Yuri Beliy, NIIP radar design bureau plans to develop a low-cost AESA radar for the aircraft.[12] According to Deputy Prime Minister Yuri Borisov, the Checkmate will share the same components and avionics as the Su-57 as a cost-reduction mechanism by the Sukhoi Design Bureau.[39][40]
Checkmate's armaments were displayed beside the non-flying prototype airframe
Armament
The Rostec chief executive said in an interview with The Wall Street Journal that the Su-75 will carry more than 7 tonnes of air-to-air and air-to-surface armaments and will be capable of striking several targets at a time.[41]
Variants
In 2023, TASS reported that the builder was working on three variants: a single-seater, a two-seater and an unmanned version.[22][42]
Potential operators
Rostec is anticipating that Argentina, India, Vietnam and Iran will become the primary export destinations for the aircraft, with the African market also showing interest.[43][failed verification] Sukhoi estimates the demand at 300 planes, and aims to export the Su-75 Checkmate aircraft to African countries over the next 15 years.[44][39] In July 2023, Dmitry Shugaev, director of Russia’s Federal Service for Military-Technical Cooperation confirmed that Nigeria was interested in the design.[22] The jet has also been pitched for export to Turkey, Saudi Arabia and United Arab Emirates[45]
In SITDEF-2021, Alexander Mikheev, the General Director of product export of Rosoboronexport stated that there was interest in the Su-75 in a number of South American countries.[19]
Specifications
Data from Flight Global,[46] Breaking Defense,[12] Suciu,[47] Global security[48] Lieser[49] and Filseth[50]
