The Su-57 Felon is marketed as stealth fighter but It has the same RCS of a clean F/A-18 Super Hornet (and 1,000 times bigger than that of the F-35). Here’s why.

The Su-57 is nowhere near F-35 for similar reasons as to why F/A-18 Super Hornets are nowhere near F-35. The gap in Stealth and ultimately Situational Awareness is just overwhelming.

The Sukhoi Su-57 (NATO reporting name: Felon) is a twin-engine stealth multirole fighter aircraft developed by Sukhoi. It is the product of the PAK FA (”prospective aeronautical complex of front-line air forces”) programme, which was initiated in 1999 as a more modern and affordable alternative to the Mikoyan Project 1.44/1.42.

Sukhoi’s internal designation for the aircraft is T-50. The Su-57 is the first aircraft in Russian military service designed with stealth technology and is intended to be the basis for a family of stealth combat aircraft.

However, even though the Su-57 is marketed as fifth generation fighter, the Felon is not a true stealth fighter and it can’t be compared to the US-made F-22 Raptor and F-35 Lightning II. Why is that?

‘Imagine if Boeing were to market F/A-18 Super Hornets or F-15 Silent Eagles with Enclosed Weapons pod and weapon bays as a ‘Stealth aircraft’ along the lines of 5th gen. aircraft, how do you think they would compare to F-35?,’ says Abhirup Sengupta, an aviation expert, on Quora.

‘That’s analogous to calling Su-57 a direct competitor to the F-35 and F-22. Sukhoi’s own patent claims Su-57 having a design RCS between 0.1 and 1 m^2.

For a known aircraft [Su-27], the EPR value is about 10–15 m 2.

The technical result, the achievement of which the invention is directed, is to reduce the magnitude of the aircraft radar visibility to an average value of the order of 0.1 – 1 m 2.

Sukhoi Su-57 Patent – RCS Reduction

‘That’s comparable to a clean Super Hornet and it shouldn’t be a surprise when Su-57 follows many of the same RCS-reduction measures such as using radar blockers to hide the engine face instead of an actual serpentine duct.

‘It’s not just Su-57 being less stealthy than F-35 (-40 dBsm) – it has a 1,000 times bigger RCS. Since detection range is proportional to the 4th root of RCS, a 1,000 times bigger RCS equates to 5.6 times greater detection range. And this is after giving Su-57 every benefit of doubt, the F-35’s RCS is very likely closer to -50 dB.’

Sengupta continues;

‘The F-35 will be enjoying almost 6 times greater detection range against Su-57. The difference is so huge that Su-57 will be hopelessly outclassed. We see this time and again in Red Flags and Northern Edge with F-35 having 28–1 kill ratio against modern 4th gen. aircraft backed by AWACS and SAMs. The enormous difference in detection range from Stealth is the primary factor for such a lopsided kill ratio.

‘It doesn’t matter how capable radar or EW suite you have, they simply can’t compensate the enormous difference in detection range from a VLO airframe. You can have amazing performance at airshows but without Stealth you’re not gonna be in a fight against 5th gen. aircraft.

‘And this is ignoring the infancy of Su-57 program and consistent delay in the production/IOC since last 4 years or the fact Su-57’s avionics suite is not remotely comparable to that of F-35. The F-35 has a bigger and much more capable radar and orders of magnitude more powerful EW suite giving vastly superior Situational Awareness.

‘Where F-35’s DAS make it the only Fighter to fully operate in the IR spectrum, Su-57 can’t even use its forward-hemisphere IRST without further ruining its RCS. The IRST is turned backwards in Su-57 because it’s a sphere, the worst shape in terms of RCS that uniformly reflects in all direction.

‘Despite all the problems with Su-57 program including lack of existence or international interest, the fundamental design is so far behind F-35 in terms of both Stealth and Situational Awareness – two key aspects of a 5th gen. aircraft. The Su-57’s design is closer to that of modern 4th gen. than it is to either F-22 or F-35.

‘Yet the Su-57 is portrayed as an equal counterpart to F-22 and F-35 with people talking about its kinematic performance or side-arrays without even understanding their actual purpose, let alone the impact on EMCON. How great are the Directed IRCMs (Laser turrets) while turning a blind eye to the fact Su-57 use a UV based Missile Warning System – making Su-57 significantly vulnerable to BVR missiles. 10 years since first flight and there’s no indication of K-77M or K-74M anywhere close to being operational, forcing Su-57 to fly with R-77 & R-74 externally (as they won’t fit inside).’

Sengupta concludes;

‘Imagine the kind of articles you’d see if F-35 didn’t have an operational missile that could fit internally. The Su-57 gets away with all the shortcomings using propaganda and fantasies, the likes of non-existent L band radar.

‘The Su-57 is nowhere near F-35 for similar reasons as to why F/A-18 Super Hornets are nowhere near F-35. The gap in Stealth and ultimately Situational Awareness is just overwhelming.’

Photo credit: U.S. Navy, Boeing, Sukhoi and Chinese Internet