Sukhoi Su-57 flight testing and development

Indeed the Su-57 has grown significantly with regards to sensors and new engines are on the way. I haven't read much about their flight testing progress on the new engines but no news is hopefully good news.

My comment was more in the direction of outward LO shape where little has changed since the first prototype which itself wasn't the pinnacle of LO design. Perhaps the Russian design is focused more around a large amount of sensors rather than a very low radar signature? Looking at construction it seems that no large effort was placed in introducing angles in access panels to aid in RCS reduction etc. Perhaps these panels are still to be covered in RAM coatings before completion but at least from a pure RCS point with respect to visible design elements it doesn't seem on par with US & Chinese designs(who themselves are not yet on US level).
 
vonstroem said:
Well, it would be hard to compare Su-57 with J-20 without actual data on RCS (numbers, not eyeballing), which is classified anyway, .
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It would yes, and I am by no means claiming to be an expert in the area but over the years plenty people much more versed in the field than me have stated that the Su-57 lacks many of the qualities that would create a significant reduction in RCS - hence my initial comment that it is disappointing that little to no change happened in this area.

Compared to a Su-35 I'm pretty sure they will have a significant decrease in RCS but compared to others is hard to say. From what I've read in pure RCS terms it isn't highly regarded. Hence my thinking that the Russians prioritized sensors to a larger degree than low RCS.
 
I can't speak to RCS well, though I've heard the same open source opinions. But I also think the Su-57 will easily have better kinematic performance over J-20 or F-35.
 
I've read a number of claims regarding the plane, too, most of them quite amusing. As far as RCS is concerned, I'm not aware of somebody publicly making an exact/accurate model and running a few tests in an anechoic chamber, for example, instead of drawing lines on a photo.
 
Well there is one, which is Carlo Kopp. No one however make a comparable studies so far specifically targeted for the aircraft.

Others often cites Chinese paper which unfortunately misleading as despite visual appearance of the model they use, their paper doesn't really have anything to do with Su-57.
 
The Su-57 does represent a significant advance in LO for Russian combat aviation, and the overall shaping in the frontal sector appears pretty respectable. That said, while it's true that making an accurate determination and comparison of RCS values would be difficult, the Su-57 does exhibit some features that call its LO into question, and those are present even in the newest "production-representative" aircraft. There are quite a few exposed metal pitot tubes and meters in the forward fuselage. The IRST bulb, even if treated, is not really an ideal shape for stealth. The grid at the bottom of the inlets present a nearly perpendicular edge in the frontal direction. Again, the LO of the Su-57 may be "good enough" for the purposes of Russian Air Force doctrine, but it's still worth keeping some of these details in mind.

As far as measuring RCS, I don't think that's quite what an anechoic chamber is for, especially at the scale of an aircraft due to near-field effects. I believe these chambers are mainly meant to test antennas and RF emitters and receivers, while actual RCS testing would be done with pole models at an outdoor range.
 
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Talking about something that makes sense, BMPD reports very concrete data about the Su-57 production for this and coming years, together with Su-35S too. Russian speakers are welcome to help make sense of the titles, some are barely visible. There is a video too, but I don't manage to see much more than what BMPD reports...

It should be:

2020 1 unit
2021 2 units
2022 4 units
2023 7 units

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There is some good information in here from 8 min mark or so onward;

View: https://www.youtube.com/watch?v=R2A3-kHoHKQ


It shows the table of production numbers for Su-35S/Su-35 and Su-57. Due to glare, it is hard to tell the Su-57 numbers exactly. If someone could do some PS magic and see if that helps (contrast etc) that would be great. But from what i can tell based upon the total number;

2020: 33-22-10= 1 Su-57 frame. (as expected)
2021: 15-8-3= 4 Su-57 frames. More than i expected tbh.
2022: 23-12-4(???)-3= 4 Su-57 frames. Unsure if the number in the table is 4 or 1. So could be as much as 7 frames.
2023: 31-14-10= 7 Su-57 frames.
2028 2024: 28, the other numbers are hard to see but look to be single digits. Meaning Su-57 could be as much as 20+ or high teens. See charly015's analysis here.

Other key points; T-50S-2 will be handed over to LIS (flight station) 20 August, in one week. The frame is planned to be handed over to MoD 30 October. Some mention of "a problem that will be discussed at a meeting" and "in regards to the frame that had an accident" (IE S-1). So sounds like they haven't agreed to how the contract will be amended etc with the loss of the frame.

At 12:23 there is a slide showing related to Su-57 production cost. Again, maybe others can figure out more here with a bigger screen, adjustment in PS etc. But slide says 40,8% reduction in "labor intensity" from initial batch on the big graph. Last number is 146,1 so first one is around 247. I am not sure what the number is exactly, man hours to build a frame? Seems the smaller blue graph on far left side is related to cost but i cannot make out the numbers here. I want to say i see "3 182" on the right graph of the two, timestamp 12:32. This works out to 43,2 million USD. If i am correct on that number, it is lower than i expected. In regards to it Shoigu jokinly says "This is the most important story for our future friendship".... Very little footage of S-2 itself, but tons of interesting info in those slides!

EDIT; Haha, i see as i was writing this long and detailed post LMFS beat me somewhat to it. :D But still, much more to extract than just the production rate...
 
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LMFS said:
2021 2 units
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I see numbers 15, 8 and 3. Which should leave 4 for Su-57 as the current Su-35S contract is finished this year.

Deino said:
Interesting since it seems to hint another 'prospect customer', so the question is: which country could this be?
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? There is only one line for Su-57 and that is for RuAF. No hints of export til after 2028 according to this slide anyway.
 
stealthflanker said:
The color. Oh and Pyroceram is a very sensible material for Radome especially if it's need to work on high temperature.
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Are we certain that's the real radome rather than a dummy cover? It's geometry is different to the airframes we know, with a larger-radius (blunter) chine, more like the Yak-130 than the Su-57s we know.
 
Deino said:
Interesting since it seems to hint another 'prospect customer', so the question is: which country could this be?
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India again? Instead of the twin seat FGFA, India goes with the standard Su-57 single seat variant.
 
flanker said:
Other key points; T-50S-2 will be handed over to LIS (flight station) 20 August, in one week. The frame is planned to be handed over to MoD 30 October. Some mention of "a problem that will be discussed at a meeting" and "in regards to the frame that had an accident" (IE S-1). So sounds like they haven't agreed to how the contract will be amended etc with the loss of the frame.
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This comes from the audio right? Not understanding Russian sucks xD

Seems the smaller blue graph on far left side is related to cost but i cannot make out the numbers here. I want to say i see "3 182" on the right graph of the two, timestamp 12:32. This works out to 43,2 million USD. If i am correct on that number, it is lower than i expected.
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My absolutely uninformed guess was RUB3 billion per unit, considering modern Flankers cost RUB2 billion and the sheer amount of new technology the Su-57 includes and references by officials to its high costs. So it makes lots of sense to me but that is just my opinion.

EDIT; Haha, i see as i was writing this long and detailed post LMFS beat me somewhat to it. :D But still, much more to extract than just the production rate...
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I was wondering why nobody had posted the news already and were still talking about RCS hahaha... but I agree there is a ton information in the video for further analysis

I see numbers 15, 8 and 3. Which should leave 4 for Su-57 as the current Su-35S contract is finished this year.
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No idea, I was just passing the numbers as stated by BMPD. How many first stage planes then, until izd. 30 appears? You talk above something about 2028, I don't know if that is a typo and you meant 2024.

Deino said:
Interesting since it seems to hint another 'prospect customer', so the question is: which country could this be?
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Are they talking about Su-57 or 35?

BTW and to avoid spliting the discusion, what do the 4 rows for the VKS Su-35 supply mean? 1st I can't see, 2nd should be new contract (how many units / how much do they cost, since we know it is RUB70B), 3rd is something like "production in advance"(?), 4th is rebuild. How do you make sense of it all?
 
Trident said:
Are we certain that's the real radome rather than a dummy cover? It's geometry is different to the airframes we know, with a larger-radius (blunter) chine, more like the Yak-130 than the Su-57s we know.
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And here is some example of unpainted radomes. That's how i got the idea from.

Military-Radomes-2-rev.jpg

booth.jpg
 
LMFS said:
This comes from the audio right? Not understanding Russian sucks xD
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Yes.

LMFS said:
My absolutely uninformed guess was RUB3 billion per unit, considering modern Flankers cost RUB2 billion and the sheer amount of new technology the Su-57 includes and references by officials to its high costs. So it makes lots of sense to me but that is just my opinion.
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My conservative estimation was 60 million USD or so. But as said, conservative estimation. 40 mil is pretty nice.

LMFS said:
No idea, I was just passing the numbers as stated by BMPD. How many first stage planes then, until izd. 30 appears? You talk above something about 2028, I don't know if that is a typo and you meant 2024.
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Izd.30 should appear from 2024-2025 or so. So 16-23 frames or so til Izd.30 off the line. I thought 2024 myself too, but in the video he says 2028 for the last column.

LMFS said:
BTW and to avoid spliting the discusion, what do the 4 rows for the VKS Su-35 supply mean? 1st I can't see, 2nd should be new contract (how many units / how much do they cost, since we know it is RUB70B), 3rd is something like "production in advance"(?), 4th is rebuild. How do you make sense of it all?
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Current contract, new contract, "early delivery" (as in building more frames in a year than allocated, happened with Su-34 atleast), repaired/modernized Su-35S' and bottom two are two export contracts. (Algeria and Egypt)
 
Deino said:
In perspective to the past experience, the still unclear economic situation and the number of so far produced aircraft since years I rate 9.5 aircraft per year most ambitious.
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I think this pace is fine for the current contract. After 2028, nothing prevents the Su-35S + from reaching the level of production speed. Although, as for me, more interesting is the question of the prospective introduction of the Su-57 in Novosibirsk or Irkutsk.
 
Re 2024 or 2028 being in the table. After thinking about it he must have stuttered and meant 2024. If one thinks of the context for the second export Su-35 contract that would make sense. It is too hard to really make out the numbers in 2024 table other than total, but i think charly015's analysis is at the very least in the ballpark. And since it is 2024, and not 2028, 12 Su-57 frames makes a lot of sense.
 
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flanker said:
40 mil is pretty nice.
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It is indeed. There are two ways of taking it: some think the Su-57 is some sort of boutique aircraft which will never be used in numbers and expected prices of $100 million and above. VKS seems to have other opinion, when they talked about the Su-57 being very expensive they were apparently meaning it rather as a Flanker substitute for the whole fleet. This at least is what that new price info would support.

Izd.30 should appear from 2024-2025 or so. So 16-23 frames or so til Izd.30 off the line.
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The basic block is 1 sqd + 4 training aircraft, so 16 planes by 2023. From then onwards, one sqd. would be equipped with first stage planes for each year of delay of the second stage. Not bad as a B plan.

Current contract, new contract, "early delivery" (as in building more frames in a year than allocated, happened with Su-34 atleast), repaired/modernized Su-35S' and bottom two are two export contracts. (Algeria and Egypt)
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Great, thanks! That would make it 28 units for the new Su-35S contract? That would be RUB2.5B each.

Re 2024 or 2028 being in the table. After thinking about it he must have stuttered and meant 2024. If one thinks of the context for the second export Su-35 contract that would make sense. It is too hard to really make out the numbers in 2028 table other than total, but i think charly015's analysis is at the very least in the ballpark. And since it is 2024, and not 2028, 12 Su-57 frames makes a lot of sense.
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Charlie's numbers make sense to me, he took also the data from Red Samovar (based on public contracts for fuselage parts) and corrected them because of the loss of the 1st serial last year. This last version seems solid, 76 units in total:

2020 - 1
2021 - 4
2022 - 4
2023 - 7
2024 - 12
2025 - 12
2026 - 12
2027 - 12
2028 - 12
 
I might be wrong here. But the "new" Radome looks slightly fatter. More needed space for Radar Array?
 
LMFS said:
Deino said:
Strange ... any explanation?
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From the angles I assume it is upside-down. But chines are not so marked as in previously seen radomes, details are missing, tip material also looks different... I would not be surprised if it is just a cover. Maybe the experts can clarify
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It's impossible to be upside down, it outright wouldn't fit.
 
LMFS said:
he took also the data from Red Samovar (based on public contracts for fuselage parts)
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Indeed, I used the Su-57's State contract number (1928187122752412208203564) and then started searching the official russian tenders website to find all the contracts linked to this state contract. And so the information were "easy" to find.

Did the same for Izd.80 PAK DA, interesting stuff found ;)
 
Re radome, imho;

- The one fitted to S-2 is just a mock up and not representative of the real one.
- S-1 had normal radome, same as previous prototypes, just an odd angle.
 
The radome seems to have a completely different shape, if that's indeed not a cover.
Most significant, imho, is the one I marked with a green line.
 

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Bhurki said:
In the lower picture, why does the right tail wing root look different to the left one?
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Different cooling requirements if I remember correctly, it was already noticed some time ago on previous airframes (there should be a discussion some pages ago about it here in this thread).

In the meanwhile, while looking at some pictures online, I've noticed that the tail cone too has undergone several changes in its shape over time, I'm not sure if anyone else has already noted this.

From top to bottom: 052, 511 and 051.
 

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Considering that T-50-1 got the tail modified with the chute for stall/flat spin testing way back in September 2012 and T-50-6-2 with longer stinger (and a bunch of other changes) first appeared in May 2016 or so, yes, it has been noted.
 
Regarding the nose cone shape change, I'm thinking it has to do with one or combination of the following;
1) Larger radar array.
2) Better radar performance through the radome.
3) Better aerodynamics, especially at high alpha. How the nose sheds it's vortexes at high alpha will affect stability.
 

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