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Sukhoi Su-57 / T-50 / PAK FA - flight testing and development Part II

CiTrus90

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In the lower picture, why does the right tail wing root look different to the left one?
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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flanker

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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.
 

Sundog

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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.
 

flanker

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Or neither, because it is just a mock up and meant to mask the radar array and assembly and not represent the actual shape.
 

Saber

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Or neither, because it is just a mock up and meant to mask the radar array and assembly and not represent the actual shape.
Then why make it in such a shape with such care to alignment? It even looks like radome material plus the "cap" on the end. All that effort for a mock up? Or a cover? You don't need it for painting or transporting the aircraft around, just standard flat red cover like on other Russian aircraft.
 

flanker

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It lacks quite a bit of detail of other radomes not to mention this is quite a radical shape difference this late into aerodynamic and RCS testing. S-1 had a vanilla radome so i think overall Occams Razor says this one will too. But we will know for sure in a few months.
 

BDF

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It could be a change for RCS requirements. Notice how the F-22 and F-35 have a similar shape. I do recall during the F-22 EMD that the kind of “pinched tip” of the Raptor’s radome was reportedly done for RCS enhancements.
 

BLACK_MAMBA

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It could be a change for RCS requirements. Notice how the F-22 and F-35 have a similar shape. I do recall during the F-22 EMD that the kind of “pinched tip” of the Raptor’s radome was reportedly done for RCS enhancements.
If it is for RCS requirements then why neglect the sharp edge present on all those before it? That blunt edge will increase the RCS again.
 

BDF

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If it is for RCS requirements then why neglect the sharp edge present on all those before it? That blunt edge will increase the RCS again.
I'm not sure what you're talking about but it would make sense that this a production design, hence an improvement. The nose on the 5th gen jets is very similar in initial shape to the "beak" on the B-2.
 

BDF

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Wow I don't know why you're getting upset. I merely stated that it may be driven by similar RCS requirements. The convex shape on the B-2 upper nose/leading edge was absolutely driven by RCS requirements and is very similar in shape to F-22 and F-35 radome shaping when looking at a longitudinal cross section of both shapes; especially as it comes to the tip. I don't think that its a coincidence. But I also freely admit I could be wrong.
 

Bhurki

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Wow I don't know why you're getting upset. I merely stated that it may be driven by similar RCS requirements. The convex shape on the B-2 upper nose/leading edge was absolutely driven by RCS requirements and is very similar in shape to F-22 and F-35 radome shaping when looking at a longitudinal cross section of both shapes; especially as it comes to the tip. I don't think that its a coincidence. But I also freely admit I could be wrong.
F-22 and F-35 radomes have to adhere to the size of their radars. B-2s nose doesn't, since it doesn't have a radar in its nose ( there are a couple on low oblique facing cheeks, 181). As such its nose design has a higher weightage given to aero and other electronics. There is simply no comparison between the two.
 

BDF

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F-22 and F-35 radomes have to adhere to the size of their radars. B-2s nose doesn't, since it doesn't have a radar in its nose ( there are a couple on low oblique facing cheeks, 181). As such its nose design has a higher weightage given to aero and other electronics. There is simply no comparison between the two.
I get that; of course the design requirements are different. What I'm talking about a very specific shaping feature on the upper leading edge of the B-2 and the 5th gen radomes. How the mold line goes from tangential to a convex curve as it converges on the leading edge/tip of the radome (The bottom of the B-2's nose is of course different.) I'm not talking about the nose as a whole. Interestingly on the B-2, this sharp shaping feature gives way to a smoother profile outboard the engines.

On the 5th gen radomes, this appears, to me anyway, that this curve is much blunter than a smoother, more aerodynamic approach on traditional fighter radomes and as I mentioned before I recall that this was discussed in one of the industry rags during F-22 EMD. In any case I am still of the belief that the changes to the Su-57's nose is RCS driven rather than aerodynamic. Again, I freely admit I could be wrong. I just don't know why anyone would get bent out of shape over this.
 

Josh_TN

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What are the two bumps above and below the fuselage directly behind below the cockpit? Some kind of wrap around EO/IR sensor like DAS on F-35?
 

FighterJock

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So the Su-57 does have EOTS though it is paired with DIRCM, I have always wondered about that.
Well, this was obvious: laser is useless as countermeasure if it can't find and track approacking missile)
Plus main EOTS was always obvious - the one in front of cockpit.
Duh!!, Thanks GARGEAN. I should have realised that. :oops:
 

GARGEAN

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Duh!!, Thanks GARGEAN. I should have realised that. :oops:
It's fine) Even if a bit strange: russian love to healthy IRST is known, and there is not too much other options of what that ball in front of canopy could've been.
 

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I thought the chin bubble and the R2D2 bubble are only lasers or do they have targeting functions built in for cueing? I thought they were cued by the other optical sensors in the 101 series.
 

GARGEAN

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I thought the chin bubble and the R2D2 bubble are only lasers or do they have targeting functions built in for cueing? I thought they were cued by the other optical sensors in the 101 series.
They do have doubled capabilities of KS-V. Most possibly reduced, but present. Makes sense, since other sensor that could've provide KS-O with targeting data is KS-U UV sensor suit, and that one doesn't possess required accuracy for laser based DIRCM.
 

Sundog

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Wow I don't know why you're getting upset. I merely stated that it may be driven by similar RCS requirements. The convex shape on the B-2 upper nose/leading edge was absolutely driven by RCS requirements and is very similar in shape to F-22 and F-35 radome shaping when looking at a longitudinal cross section of both shapes; especially as it comes to the tip. I don't think that its a coincidence. But I also freely admit I could be wrong.
Actually, no. One of the main reasons the B-2's nose is shaped the way it is is because of aerodynamics and how flying wings stall.
 

Flyaway

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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...
Video has been removed.
 

medal64

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As far as i see from the video is HUD of the 057 board is new generation and probably the cockpit layout too thats why Mr. Shoigu looks carefully.
 

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flanker

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That is a good observation/point. Personally i havent even noticed that the HUD changed but you are right. On S-2 it is different from both new screen/HUD pic above and from prototypes though. So there is atleast 3 variations? 057 would be a prime candidate to modify and test these things as it is T-50-KNS.

Also of note, atleast the sidebays appear to be open, but of course with the specific camera angles we dont see much :)
 

TR1

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Also a phased (AESA?) array can be seen on a Ka-52 in the vid.

As always during Army event, they don't photograph or give enough details about the real interesting stuff.
 

LMFS

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I think this may be an indirect confirmation of the numbers and dates we saw in the KnAAPO visit: around minute 2:00 I understand Slyusar confirms the first Su-57 squadron will be completed in 2024 as we said before and the VKS wants Okhotnik deliveries to start by then too. Maybe some Russian speaker can confirm... :)

View: https://www.youtube.com/watch?v=5RiMZuFfJGI
 
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