Latest thoughts on new Russian mystery fighter aircraft: ‘Fleabag’ achieves checkmate

Though earlier artists impressions show an undernose intake the aircraft or mock-up appears to have should mounted intakes somewhat reminiscent of those of the F-22 and to a lesser extent, the Berkut. I do wonder what their intake shape is… and there are rhomboid options that would make M~2.0 feasible. I think this aircraft is a candidate for MiG-29 replacement, but with emphasis shifted away from WVR combat.

TASS has announced that Russia’s latest fighter aircraft will be unveiled, and, indeed, demonstrated, at the MAKS-2021 show on July 20.

Photographs of the shrouded aircraft (or possibly mock-up) have now appeared, and the analysis below has been updated to reflect these images.

The aircraft is reported to be Russia’s first single-engine supersonic low observable tactical fighter, and has been developed by Sukhoi, and is being presented at the MAKS show by Rostec. The stated intent is to ‘rival the US fifth-generation F-35 aircraft’. The aircraft is also described as a domestic light fighter, which will compete with the F-35 in export markets. This latter comment is backed up by a video on the Rostec website which identifies a number of countries by name including India, Argentina, and Vietnam, and some imagery suggestive of Middle Eastern states.

The new photographs show an aircraft that loosely resemble the earlier ‘teaser’ imagery, but with significant differences in the intakes and fuselage.

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Compared to the ‘teaser’ imagery, the ‘Checkmate’ aircraft (Hush Kit reporting name ‘Fleabag’) has twin intakes located on the sides of a rhomboidal cross-section fuselage, resembling the intake installation on the F-22, rather than a large diverterless intake under the nose. The wing appears to be similar to the teaser image, being highly-tapered, thin, and with a low-aspect-ratio, near-diamond planform.

The forward fuselage of the teaser image had a small forward canard, which appears to be absent on the shrouded ‘Fleabag’ aircraft. The shrouding of the aircraft is very effective in confusing the aircraft profile, and it is not impossible that a strake is present, in the same plane as the wing, and that the intakes are below this strake, rather like the F-18 installation. All of this must remain speculative until clearer images are available. 

The rear view of the Fleabag appears to show a single afterburning nozzle, located between twin butterfly tails. Given Sukhoi experience in the application of thrust vectoring to its heavy fighter designs, it would be surprising if this were not also fitted to the new aircraft. The teaser image features an Infra-red Seeker Tracker, located ahead of the cockpit, and a radar in the aircraft nose. This would be a typical arrangement for a Russian fighter.

A once classified British study from 1993 shows a similar design solution in wing planform and tail configuration.

The wing planform and tail design are somewhat reminiscent of the McDonnell MFVT (Mixed Flow Vectored Thrust) ASTOVL concept, and as this single-engine aircraft featured twin side-intakes, there is quite a strong resemblance between it and what we can see of ‘Fleabag’. The Newark Air Museum in the UK have a model of that concept, shown below. The MFVT design was one of the propulsion alternatives examined in early UK-US joint technology studies looking at possible ASTOVL concepts in advance of the JSF program. I am not suggesting that Fleabag is a STOVL aircraft, however – the fuselage volume taken up in the MFVT for its STOVL system simply results in a fuselage shape compatible with the internal weapons bays which must surely be a feature of Fleabag.

What can we infer about the aircraft? To me, the highly-tapered, low aspect ratio wing suggests that the design is intended to be used for BVR combat, as the wing area and aspect ratio suggest sustained turn performance might not be a strong point. Checkmate is likely to have a high thrust-to-weight ratio, a vectoring nozzle and a strake ahead of the wing. This should result in the instantaneous turn rate being structurally, rather than aerodynamically, limited for substantial parts of the manoeuvring air combat envelope. The fuselage below the wing line is rhomboidal, the flat sides and fuselage width suggesting reasonable size internal weapons bays, which are necessary if the aircraft is to have a low signature.


Whether a low signature is achieved will depend on a number of aspects – not just the shape, but the materials, the manufacturing standards, and the electromagnetic properties of the surfaces and structure. Certainly, some are firmly of the view that the canard foreplane, and the large under-fuselage intake, are incompatible with a low signature aircraft. It is interesting that these features do not appear to be present in the shrouded Checkmate/Fleabag aircraft.

From the wording used in the press release – descriptors like ‘domestic light fighter’ and ‘tactical fighter’, and the reference to exporting the aircraft, it could be that the new Sukhoi is intended to be a cheap alternative to the F-35, indicating, perhaps, that some compromises in the signature area might have been made in the interests of containing acquisition, operating and maintenance costs.


Could the aircraft be a Russian equivalent to the Hush-Kit F-36 Kingsnake concept, aiming to regain the position once achieved with the widespread use of the MiG-21, by undercutting the cost of the F-35? The primary intent might be to develop a widely exportable aircraft, with, perhaps, Russian usage being limited to a ‘non-exportable’ variant used for local air defence and tactical strike. This might supplement a force mix including manned and unmanned systems, and drawing on the capabilities of future systems like the Su-57 for air superiority, and a future MiG-31 replacement. for strategic air defence.

 Could the aircraft indeed be a Russian equivalent to the @Hush_Kit F-36 Kingsnake concept, aiming to regain the position once achieved with the widespread use of the MiG-21 by undercutting the cost of the F-35?

– Jim Smith

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  1. AndrewZ

    The F-35 will only be sold to wealthy nations which can afford the huge price tag and which have sufficiently good relations with the United States to be trusted with some of its most advanced military technology. There are very few nations which meet both these criteria and which might also be willing to adopt Russian kit, so there are likely to be very few (if any) cases in which the F-35 and “Fleabag” are directly competing for sales. But there could well be a market for a cheaper and more widely-available fifth-generation aircraft that can perform a broadly similar role to the F-35.

    I would be surprised if Argentina buys it. The Argentinian air force has suffered badly from decades of inadequate funding, so it seems doubtful that they would have the budget to purchase and maintain a new fifth-generation fighter in sufficient numbers to be effective.

  2. peter

    The biggest shame on the F-35 was this.
    2018 Testfight against French Alphabet ( Rafale-fighter-pilot) and the
    F-35 was outmatched in the simple low-altitude-dogfight ( under 9000 fts) with the intern 30mm Gun and Sidewinder / rd550-sim.

    If you want to drive a car = PORSCHE 911 and not Tesla. okay.
    This Suchoi is based on the problems of the F-35.
    And not so expensive, ore so butifull ex expensive like Euro fighter Typhoon.
    but funny all this.. 🙂

    Peter Marsh. Austin Texas 🙂

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