After five years of mock-ups, promotional renders, and slipping deadlines, Russia’s answer to the F-35 is finally taking physical shape. On June 2, 2026, Vadim Badekha, General Director of United Aircraft Corporation (UAC) – the state-owned conglomerate under Rostec that oversees Sukhoi and Russia’s other major aircraft manufacturers – told the state news agency TASS that construction of the first flying prototype of the Su-75 Checkmate had begun. “The work on Checkmate is already at the stage of building a prototype aircraft,” Badekha said, speaking ahead of the St. Petersburg International Economic Forum.
It is a modest sentence carrying a fairly large amount of weight. For half a decade, the Checkmate has existed mostly as a full-scale mock-up, a stream of digital renders, and a series of confident press statements. This is the first confirmation that Sukhoi has moved past the display-model phase and started physically assembling a jet meant to actually fly.
A Light Fighter With a Heavy Sales Pitch
The Su-75, internally designated the T-75 by Sukhoi and referred to in Russian military aviation circles as the LTS, or Light Tactical Aircraft, was unveiled by Sukhoi at the MAKS 2021 airshow as a single-engine, low-observable multirole fighter sitting below the heavier, twin-engine Su-57 in Russia’s fighter hierarchy. The concept revives a category Soviet industry once dominated and mass-produced by the tens of thousands: lighter, single-engine combat jets such as the MiG-21, MiG-23, MiG-27, and Su-17. Russia has had almost no presence in that segment for decades, and Badekha has been explicit that reviving it matters to UAC as much as the aircraft itself does.
Where the legacy aircraft were straightforward fourth-generation fighters, the Checkmate is being pitched as something else entirely: a fifth-generation jet, built around reduced radar signature, internal weapons carriage to preserve that signature, digital flight controls, modular avionics, and what Sukhoi describes as built-in artificial intelligence assistance for the pilot. Its core selling point, repeated by Badekha in nearly every public statement on the programme, is cost. A single engine is simpler and cheaper to maintain than two, and that translates directly into lower acquisition and life-cycle costs for any air force buying it.
According to figures Russia has released, the Checkmate has a maximum takeoff weight of around 26 tonnes, can carry up to 7,400 kg of weapons and equipment across internal and external hardpoints, mounts a 30 mm automatic cannon, and is projected to reach speeds in the Mach 1.8 to 2.0 range with a combat radius of up to 2,800-2,900 km. UAC has stated the export version will carry a price tag of roughly $30 million, and has gone as far as to say Western-made components could be integrated at a customer’s request – an unusual offer for a Russian combat aircraft, and one clearly designed to widen the pool of potential buyers beyond states already locked out of Western suppliers.
Three variants are reportedly planned: a single-seat baseline version, a two-seat trainer or operational variant, and an uncrewed version, the latter pointing toward Sukhoi’s longer-term interest in autonomous combat aircraft – a trend that is reshaping fighter programmes well beyond Russia, from the U.S. Air Force’s Collaborative Combat Aircraft initiative to Turkey’s Baykar Kizilelma uncrewed fighter, which is set to join the Turkish Navy’s carrier fleet this year.
A Programme That Has Slipped Three Times Already
It is worth being upfront about the Checkmate’s track record, because it shapes how this announcement should be read. When Sukhoi unveiled the aircraft in 2021, the company projected a first flight in 2023. That date slipped to 2024. Then to 2025. The current public target, repeated by multiple Russian officials including Sukhoi chief test pilot Sergei Bogdan in a November 2025 television interview, is sometime in 2026, with independent industry trackers now estimating a more realistic window of late 2026 to 2027 for the aircraft to actually leave the ground.
That history of repeated delay is the backdrop against which Badekha’s announcement needs to be weighed. Confirming that a prototype is under construction is a genuine and verifiable step forward; it is not, however, a confirmed delivery date, and it does not resolve the structural challenges – sanctions-driven supply chain constraints, the demands of simultaneously sustaining wartime aircraft production, and the technical difficulty of fifth-generation systems integration – that pushed the previous three deadlines past their original targets.
In Russian aerospace terminology, what Badekha confirmed is that the programme has reached the stage of building an opytny obrazets, or experimental prototype. That is a specific and meaningful milestone, but it sits well before flight testing. Before any prototype leaves the ground, it typically passes through a long sequence of ground-based verification: installing the powerplant, running engine start-up checks, validating avionics, testing electrical and hydraulic systems, verifying flight-control software, checking the fuel system, and running structural load assessments. For an aircraft combining a single-engine layout, internal weapons bays, and low-observable shaping for the first time in Russian fighter design, that testing sequence is likely to be more demanding than usual, since any one of those systems failing to integrate cleanly can cascade into further schedule slippage.
A Redesigned Airframe Hiding Behind the Same Name
One of the more technically interesting threads in this story is the possibility that the aircraft now under construction is not simply the jet Sukhoi displayed at MAKS 2021, built at last, but a meaningfully revised aircraft wearing the same name.
In 2023, Russia’s Federal Service for Intellectual Property published a series of patents filed by the Sukhoi Design Bureau describing a reworked Checkmate configuration. The filings pointed to changes in the rear fuselage shape, enlarged flaperons along the trailing edge of the wing, slightly extended leading-edge root extensions, and modified outer wing panels – changes that appear to borrow aerodynamic logic already proven on the Su-57 programme. None of this is cosmetic tinkering. Alterations of this kind affect how the aircraft generates lift, how it handles at high angles of attack, how pitch and roll authority are distributed, how much internal volume is available for fuel and equipment, and critically, how the airframe reflects radar energy from the rear aspect – a detail fighter designers treat with particular care, since a weak rear-aspect signature can undermine the survivability benefit that low observability is supposed to provide in the first place.
If the prototype now under construction incorporates these patented changes, it suggests Sukhoi has spent the years since 2021 not just struggling to fund and schedule the programme, but actively refining the aircraft’s aerodynamics using computational fluid dynamics modelling, wind-tunnel testing, structural analysis, and feedback gathered from potential customers – a fairly normal part of any fighter’s development cycle, even if it is one that rarely gets confirmed this explicitly in public reporting. It would mean the aircraft that eventually flies, and the aircraft that was unveiled five years ago, may look subtly different to a trained eye, even if the overall silhouette and marketing name remain the same.
Su-75 Versus Su-57: Two Different Bets
Russia is not abandoning its existing fifth-generation fighter to build this one. The Su-57, a twin-engine heavy fighter that entered serial production in 2020, remains the VKS’s (Russian Aerospace Forces) higher-end platform, with greater internal fuel volume, payload capacity, range, and the operational safety margin that comes with having two engines instead of one. The Su-75 is explicitly positioned as a complement to the Su-57, not a replacement for it – a lighter, cheaper aircraft intended to handle air defence, tactical strike, and general multirole missions at a fraction of the cost, while the Su-57 covers longer-range missions, heavier weapons loads, and more sensor-intensive tasks.
That division of labour mirrors, in rough outline, the relationship between the F-22 and F-35 in U.S. service, or the high-low fighter mix many air forces have pursued since the Cold War. The trade-off for Russia is that a single-engine aircraft places far greater importance on the reliability of that one engine, and on the quality of systems integration generally, since there is no second engine to fall back on if something fails mid-flight. If Sukhoi can make that trade-off work, the VKS gains a more flexible, numerically larger fifth-generation fleet than it could afford if every airframe were a twin-engine Su-57.
Why Russia Wants This Aircraft to Succeed
Badekha was direct about the export logic behind the programme, telling TASS that the aircraft is being developed for both the Russian Ministry of Defence and prospective foreign buyers, with delivery timelines depending on customer interest and individual operator requirements. Russia has long used combat aircraft sales as a tool of foreign and defence policy, offering platforms to states that cannot, will not, or are not permitted to buy Western equipment. The Su-75 is shaped specifically for that market segment: a fifth-generation jet for countries that want one but find the F-35 – whether for cost, political, or procurement-access reasons – out of reach.
Whether that pitch succeeds depends on more than price. Sukhoi will need to demonstrate the aircraft can be manufactured reliably under continuing Western sanctions, and that its radar, engine, avionics, and weapons integration can meet the expectations of foreign air forces who are, by definition, comparing it against the F-35 and against China’s own export fighter offerings. A $30 million price tag is meaningless to a customer if the aircraft cannot be supported through its service life, or if production quality proves inconsistent – both genuine risks for a programme already several years behind its own original schedule.
There is also a symbolic dimension to the project that Badekha himself has leaned into. The Soviet Union built tens of thousands of single-engine fighters and was, for much of the twentieth century, one of the dominant suppliers in that category globally. Russia’s absence from that market since has been, in industry terms, a gap rather than a deliberate strategic choice, and the Checkmate represents an attempt to close it using modern, fifth-generation technology rather than a fourth-generation design updated for the 2020s.
What Comes Next
The construction of an experimental prototype is a genuine milestone, but it is one step in a long sequence, not the finish line. Sukhoi and UAC still need to complete the prototype’s structural assembly, push it through ground and bench testing, conduct taxi trials, achieve a first flight, expand the flight envelope gradually to validate handling and performance, and integrate the weapons systems the aircraft is supposed to carry – all before any conversation about serial production or troop deliveries becomes realistic. Badekha’s own comments to TASS notably avoided naming a delivery date to Russian forces, which is itself a signal that internally, UAC is not yet treating that question as answerable.
What the prototype’s eventual first flight will reveal, more than anything, is whether Sukhoi has used the lost years productively. If the aircraft on the runway reflects the more refined aerodynamic configuration hinted at in the 2023 patent filings, the Checkmate that eventually flies could be a meaningfully more capable aircraft than the one displayed at MAKS five years ago. If it does not, the programme will face the same question that has hung over it since 2021: whether Russia’s aerospace industry, stretched by sanctions and by the demands of sustaining wartime aircraft production, can carry a genuinely new fighter programme through to operational service on anything resembling its stated timeline.
Final Thoughts
The Su-75 Checkmate has spent five years as a promise: an airshow mock-up, a set of ambitious specifications, and a sales pitch aimed at air forces priced or politically barred out of the F-35. That promise has now produced something that can be measured with calipers rather than read off a press release – a prototype on Sukhoi’s shop floor. Whether it becomes a fielded combat aircraft, an exported alternative to Western fifth-generation fighters, or another ambitious Russian aerospace programme that stalls under the weight of sanctions and industrial strain, depends entirely on what happens in the testing campaign now beginning. For an aircraft that has already missed three of its own deadlines, the next milestone worth watching is not another statement to TASS, but the day Checkmate’s wheels actually leave the ground.
