US Naval Aviator explains why both the Su-57 Felon and the J-20 Mighty Dragon are not Fifth Generation Fighters

Are both the Su-57 and the J-20 true fifth generation fighters?

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.

The Chengdu J-20 Mighty Dragon is a single- and twin-seat, twinjet, all-weather, fighter aircraft developed by China’s Chengdu Aerospace Corporation for the People’s Liberation Army Air Force (PLAAF).

The J-20 is designed as a fighter with precision strike capability; it descends from the J-XX program of the 1990s. The J-20 made its maiden flight on Jan. 11, 2011, and was officially revealed at the 2016 China International Aviation & Aerospace Exhibition. The aircraft was in military service by March 2017, with the aircraft officially entering combat training phase in September 2017.

Are both the Su-57 and the J-20 true fifth generation fighters?

‘Everyone knows which aircraft we’re talking about,’ Adam Daymude, former US Naval Aviator, says on Quora.

‘Here’s the Su-57:

‘And here’s the J-20:

‘Both purports to be 5th generation fighters. But let’s take a look, shall we.

‘Both are twin-engined, twin-tailed. Good start. Both have canted vertical stabilizers, though the J-20 is more so. Most likely a point to the J-20. They both have blended fuselages, point to both. Now let’s look at angles. On the J-20, I count at least 7. The Su-57 has at least 8 I can see. And we won’t even address the front of the fuselage where the cockpit is because you’d need a supercomputer to figure out that part’s stealth features. And those canards on the J-20 are a problem.

‘Taking them both in, and trying to neutrally evaluate them, they both look like they could be some competent aircraft. 5th gen though, I highly doubt it. They certainly have a reduced RCS but I can just tell by looking that it won’t be in the same league as a Raptor or Battle Penguin. In fact, published RCS for the Felon is an order of magnitude worse than either of them. I can’t overemphasize enough how bad those canards are for RCS on the J-20; I can almost guarantee its RCS is worse than the Felon.

‘That’s just me looking at the planform of these jets. If you consider the engines as well, they fall even shorter when compared to our 5th gen jets. But it’s very likely our jets are overkill, designed to defeat the most sophisticated air defenses out there. Take either the J-20 or Su-57 against a typical adversary and it would be a big jump over what they have already.’

Daymude concludes;

‘I’d put them in the gen 4.5, or maybe 5-, series of aircraft. I can’t place them in 5 because I have too many questions on their stealth capabilities.’

Photo credit: Own work N509FZ and Vitaly V. Kuzmin via Wikipedia