A marketing campaign seemingly inspired by Marvel’s Avenger movies has enabled Russian military industry conglomerate Rostec to successfully built up a tidal wave of hype in advance of the unveiling of its new “Checkmate” single-engine stealth jet concept.

First, a teaser trailer released by Rostec depicted Argentina, India (currently seeking 114 jet fighters), Vietnam and the United Arab Emirates as potential buyers. Then a full-scale mockup of the small, needle-nosed jet was presented to Putin on July 20, 2021, in a fluorescent light show at the biannual MAKS airshow near Moscow, though photos of the jet had already leaked online a few days prior.

Sukhoi, Russia’s preeminent jet fighter manufacturer, has been struggling to ramp up production of twin-engine Su-57 multi-role stealth fighters, with only four to be delivered this year. But in 2020 it began privately developing a Light Tactical Aircraft (LTA) drawing on Su-57 components aimed at foreign buyers eager to acquire stealth jets on the cheap and/or without having to go to Washington for F-35s.

Defense official Yuri Borisov stated Sukhoi hopes to solicit foreign financing and expects to export over three hundred Checkmate jets over the next fifteen years. Rostec CEO Sergei Chemezov also assured the Russian military would purchase Checkmate aircraft, and claimed, rather dubiously, the new jet would cost $25-30 million apiece, not only around one-third the cost of an F-35A, but cheaper than Russia’s non-stealth Su-35S fighter.

If the Checkmate receives government financing—which again, is not guaranteed—it will supposedly make its first flight in 2023, followed by prototype aircraft in 2024-2025, with development concluding and serial production commencing in 2026-2027. This ultra-rapid schedule is highly optimistic, considering it took over two decades to get the Su-57 and F-35 stealth jets into operational service.

Still, strength of concept could conceivably lead Checkmate to complete development, so let’s review what’s proposed.

Flight Performance

Checkmate would likely be powered by a thrust-vectoring AL-41F turbofan engine, theoretically allowing the jet to achieve a service ceiling 54,000 feet and a maximum speed of Mach 1.8, on par with most modern non-stealth fighters. Reportedly, the airframe will withstand up to eight times the force of gravity (most modern fighters can withstand nine Gs) and can rapidly accelerate and maneuver thanks to a 1+ thrust-to-weight ratio. Supposedly it will “maintain continuous supersonic flight”, though supercruise (supersonic cruising without afterburners) hasn’t been claimed.

Curiously, some sources claim a speed of Mach 1.53 (1,900 kph). Perhaps the higher figures assume the use of the improved izdeliye 30 variant of the AL-41F, which has not yet completed development.

The jet would have a good maximum payload of 8.1 tons, a maximum range of 1,864 miles, and a combat radius of 932-1,180 miles. That’s unusually far for a lightweight jet, and could be extended using a retractable air-refueling probe.

All-weather/climate capable, Checkmate would supposedly be able to take off and land from short runways thanks to its thrust-vectoring engine, exhibit low per-flight hour operating costs and maintenance requirements, and wouldn’t require special ground-based infrastructure to operate.

Sukhoi also boasts the aircraft’s modular architecture could easily facilitate the development of a two-seater model (ideal for training and ground attack), a carrier-based variant with a reinforced chassis, client-tailored export models, and an unmanned combat drone variant aimed at Russian military procurement.

Weapons

Checkmate would be compatible with a broad menu of guided weapons already integrated into the Su-57. That includes export variants of the short-range R-74 and beyond-visual-range R-77-1 and R-37M missiles; Kh-35 and Kh-59MK anti-ship cruise missiles; Kh-58UShKE anti-radar missiles; Grom, Kh-31PD and Kh-38 air-to-surface missiles; KAB-250 laser-guided bombs, and K08BE and K029BE satellite-guided bombs.

It could also carry unguided bombs and S-8 and S-13 rocket pods, and a cannon could be installed in one of the side weapon bays.

Sensors and Avionics

Besides the usual Infrared-Search and Track (IRST) sensor in front of the cockpit, Checkmate would reportedly mount a jam-resistant Actively Electronically Scanned Array (AESA) radar that can engage six aerial or two ground targets simultaneously. The radar and IRST would be integrated with additional sensors, forming a passive multi-band sensor array working in tandem with a defensive/offensive electronic warfare system.

AESA radars are the current gold standard, but Russia has struggled to integrate them into fighters. Checkmate’s radar might also be restricted in aperture by its small nosecone, and the presentation notably doesn’t mention active low-probability-of-intercept (stealthy radar) capability.

Checkmate’s cockpit instrumentation appears similar to the Su-57’s, though separate displays have been consolidated into one large Liquid-Crystal Display (LCD). Rostec has emphasized that Artificial Intelligence will ease the task load on pilots by performing self-diagnostics prior to takeoff and co-piloting during combat. The new jet could also serve as a hub for controlling multiple combat drones, as is planned for the Su-57.

To ease maintenance, Checkmate would feature a Matreshka automated logistics support system which could schedule predictive maintenance, and an Auxiliary Power Unit allowing activation of the aircraft’s systems without powering up the engine. Rostec also promises good post-sale services and low maintenance costs, seeking to counter the poor reputation Russian aerospace manufacturers have in those domains.

Stealth Design

Potential buyers may be especially interested in the extent of the Checkmate jet’s potential stealth characteristics, which remain unquantified. Already, non-stealth jets like the Boeing F/A-18E/F Super Hornet and Eurofighter Typhoon boast significantly reduced radar cross-sections of 1.5 to .5 square meters, so Checkmate must achieve substantially lower observability to be credibly described as a stealth aircraft.

Checkmate’s geometry clearly exhibits features intended to minimize radar reflectivity such as the chin (‘sharp’ thinned edges) in the aircraft’s nose and the use of canted ruddervators/tailerons similar to those in Northrop’s YF-23 Black Widow stealth fighter prototype. Its stealthier but trickier control surfaces, as opposed to traditional horizontal and vertical stabilizers, require more aggressive intervention from the flight computer.

The mockup’s under-chin jet intake is also intriguing. Ordinarily, a turbofan’s engine’s fan blades are highly radar-reflective, but Sukhoi may intend to use a Divertless Supersonic Inlet (DSI) like that on the F-35 designed to obfuscate the fans.

Like any proper stealth aircraft, Checkmate has internal weapons bays. Two inlet-mounted ‘cheek’ bays can launch short-range air-to-air missiles, with larger munitions stowed in a ventral bay, for a maximum load of five internally stowed air-to-air missiles.

But Checkmate’s stealth can’t be judged from appearances alone because radar-stealth isn’t just a factor of airframe geometry—it depends on the use of composites and radar-absorbent materials (RAM) and the finesse of manufacturing. For example, closeup images do not show the non-flush screws and joints necessary for achieving higher degrees of cross-section reduction.

Can Checkmate possibly takeoff?

The concept jet still requires government funding from Russia and/or abroad to transition from concept to a fully-developed reality—and that is far from guaranteed given the Russian military’s apparent preference for heavier fighters. Consider that Moscow only ordered token quantities of the new lightweight MiG-35 jet, scaring away export clients of which there remain none confirmed. 

Even given state money, experience developing the Su-57 (and U.S. stealth jets too!) suggests Checkmate is unlikely to be developed as rapidly and cheaply, nor produced in such volume, as initially claimed. And due to outstanding demands for Su-35, Su-57, and Su-34M jets on existing production lines, Checkmate would likely require outfitting a new production line at cost.

That said, Sukhoi believes it can save time and money by slotting in technologies developed for the Su-35S and Su-57 fighters, and trusts (like futurists in the U.S. Air Force) that new computer-assisted design technologies will drastically reduce development time.

If a Checkmate fighter emerges that can achieve the parameters claimed—particularly long-range, low cost and respectable very-low-observability—it could yet prove commercially attractive, even if the price tag isn’t entirely as low as claimed.

But while Rostec’s strategy of targeting countries that can’t access or afford F-35s is plausible, consider that China’s Shenyang FC-31 lightweight export-oriented stealth jet, privately built by a firm with more spare cash, is already competing for that niche and hasn’t yet received orders. And by the late 2020s, rivals could emerge including the heavier Su-57E and “economy”-class stealth jets developed by India, South Korea and Turkey, unburdened by possible Countering America's Adversaries Through Sanctions Act (CAATSA) sanctions imposed by Washington.

For now, observers must wait to see if Checkmate receives the state funding needed to transform it into more than just a cool design concept boosted by a spectacular marketing campaign.

Sébastien Roblin holds a Master’s Degree in Conflict Resolution from Georgetown University and served as a university instructor for the Peace Corps in China. He has also worked in education, editing, and refugee resettlement in France and the United States. He currently writes on security and military history for War Is Boring.

Image: Reuters