Sukhoi Su-27/30/33/35/37 Flanker series & Su-34 Fullback - History, Design, Performance & Dissection (Part 1)

  1. Poor Blue 20 is missing her Vert-stab wing tips, my reference photos show her with standard wing tips.
    image

  2. So the issue is that we have a T-10S (Su-27, essentially) in game, but they’re using values from the T-10, not the T-10S. Again, I wonder, what early T-10 FM values are they even using? Not every early T-10 airframe even has the same shape.

How is it not? The early T-10’s had AL-21’s, that has to be a problem as well.

Early T-10 airframes are way different than the T-10S and suffer from horrible AOA, let alone none of the Flankers are really capable of stable flight without Fly-by-wire, so T10-1 for example going to be clunky as hell as it’s semi-mechanical.

Smells like T10-1 to me.

From discussing this all so far it seems like T10-15 (T10S) with individual Oswald efficiency to each part (possibly why flaps/flapperons and trim are all crap), remaining values are all all from T10 early model, and thrust may be modelled incorrectly as well.

Absolute sh*t show, like I said.

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If anyone has something to add, you can suggest me changes to this bug report on Russian or even post your own comment there on English

I wish I knew what was going on on the client side enough to make a report, but everything seems normal as far as I can tell. I’ll do some more reading to see what I can figure out.

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This would explain why the basic airframe dimensions are off in the game files.

Which is why they are using erroneously calculated AL-31 installed thrust data from the other manuals. They are also not without flaws.

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Okay. But the plane is supposed to have AL-31’s, so the thrust isn’t the problem per-se. If we had a T-10-1 or any other early T-10, it would have AL-21F-3AI’s. The T-10S has AL-31’s. So the thrust might be right, but the dimensions, weight, and thrust curve might be off. I don’t know what the data looks like behind the client, I’m not good at figuring that stuff out, but it sounds like we have a Frankenstein Su-27 and Su-27SM.

This also explains while it’s still a brick, the Su-34 must have a cleaner FM, as there’s less crap for Gaijin to confuse it with. Having the AL-31F-M1’s must be doing a lot of work for that model as well.

I haven’t flown the Su-33 yet, but I’d imagine it too feels like a better Flanker in the intense AOA’s and low speeds.

No, it is not. The thrust is wrong, intake losses are not as high as they should be. Excess thrust is compensated by excess drag.

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I’m trying to understand what this means. Are you saying the intake loss should be worse on the Su-27? And that it’s compensated for by excess thrust from the dev’s modelling or when the afterburner is engaged? Are you saying that this issue, which may be essentially fixed/compensated for is then compounded by the problem of excess drag on the flight model?

Multiple early T10’s have different intake designs, and I’m not sure they all had intake ramps for different positions. So if we have a Frankenstein model for drag and other coefficiencies on the Su-27 based off of an early T10, not the T10-15, then the entire intake process is completely screwed.

I don’t think the game models intakes with different flaps for different positions on the throttle and air speeds. So that’s a problem too.

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Thrust is higher than it should be because intake losses are not properly accounted for.
To account for the excess thrust, they increased the drag.
The increased drag and thrust was also “amended” by a terrible oswald coefficient and made worse by incorrect geometry of the basic airframe in the files.

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Yes, that’s right, they compensated for the excessive drag with thrust

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How FM will feel when excessive thrust and drag will be fixed? Smaller speed bleeding but slower acceleration?

Speed bleed will be better, turn and AOA will be better, but sustained 1 circle fighting will drag you lower and slower faster.

In theory it should give you the ability to gambit and lock anyone at least once.

Should climb a bit better, and sustain flight a little better as well.

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If they used a mish-mash of T-10 models for the Su-27 I shudder to think of how they decided the Su-33 should fly…

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the su-27 situation is crazy

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It’s not even crazy, it’s plain stupid.

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The plane also doesn’t accelerate correctly at lower angles of attack. At a 5G turn it will accelerate but it’s still short of its manual by 15 percent.

The entire lift/drag curve of the plane is completely wrong.

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The geometry of the airframe is incorrect even in the files.
So Flanker flight model being horrifically bad isn’t a surprise at this point.

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On a slightly more unrelated note…
How accurate is the Su-27S DCS module flight model?
I would assume it is way better than the War Thunder Su-27S.

@BBCRF

Frankly. It may have actually been a little different given the dimensional changes to the wings etc. Again, this is part of the reason why I think the Su-34 feels like the first real Flanker, I think they built it it’s own FM.

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The DCS is also not accurate, but it is much better than the WT

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attempt number two
https://community.gaijin.net/issues/p/warthunder/i/nEtnXhhHysKD

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