Russian Su-57 Aircraft Thread (PAK-FA and IAF FGFA)

[anzha]

The 2nd production example. There at least 2 delivered now i guess.

So we have two delivered. Are the other three that were for December coming shortly?

That makes at least 3-5 airframes now.

? Of what version?

 

[Stealthflanker]

? Of what version?

Production. Like we have 1 last year. and 2 more now. If 4 is to be believed to be delivered then we will have 5.

 

[gelgoog]

How come it is Bort 52 Blue instead of 02?
I know there are reports that two aircraft have been delivered. The airframe also looks like a production variant. But 052 used to be one of the prototypes. So...

 

[james smith esq]

This is a stagnant program!

 

[Qian CDer]

This is an interesting paper on Su75 from CAC.

 

[Qian CDer]

And...
It proposes:
Su75 has a bad pictn control.

Su75 has a suspicious range of a flight.

Su75 has a better stealth design than
Su57[0.1~1㎡ RCS],but it's still bad.[IRST alone provides 0.02㎡ RCS]

Su75 has a lower thrust for its take-off weight,even with lzdelie-30.It will make a lower thrust-to-weight ratio than F35.

Su75 has a bad lift-drag ratio in subsonic speed.

Su75 may only"Continuous Supersonic Flight",not "supersonic cruise".

Su75 may uses Su57's H036-1-01, this is a AESA which completely behind AN/APG-77 or AN/APG-81.This radar will have a lower detection distance than Irbis-E.[Interestingly, CAC also points out that although Irbis-E is called the strongest PESA, it can only be comparable to F14's AN/AWG-9 in many ways.]

Su75 is more capable in BVR or air-to-surface than Su57, because of its more stealth design.But it's not suitable for dogfight because of its lower thrust-to-weight.

––––

Ah, no, I'm sorry.
I realized I posted it in the wrong thread and can't delete it.

 

[gelgoog]

It proposes:
Su75 has a bad pictn control.

Su75 has a suspicious range of a flight.

Yes I am sure Sukhoi spent many years on an airframe design they knew would not work. You do know there was a competition for the LMFS between Sukhoi and Mikoyan almost two decades ago and this design is probably that old right?

Su75 has a better stealth design than
Su57[0.1~1㎡ RCS],but it's still bad.[IRST alone provides 0.02㎡ RCS]

Calculations done by someone who clearly does not know what they are doing. The IRST dome is transparent to radar. Calculating its RCS as if it was some kind of solid metal ball is idiotic.

Su75 has a lower thrust for its take-off weight, even with lzdelie-30. It will make a lower thrust-to-weight ratio than F35.

No it won't. Plus the Su-75 has a much smaller frontal area than the F-35 so it should have a lot less drag.

Su75 has a bad lift-drag ratio in subsonic speed.

Compared with what? This is a supersonic jet fighter not a subsonic ground attack aircraft.

Su75 may only"Continuous Supersonic Flight",not "supersonic cruise".

So at worst it will be just like the F-35 you mean? I would not be surprised if it could do supersonic cruise with the Izd. 30 engine.

Su75 may uses Su57's H036-1-01, this is a AESA which completely behind AN/APG-77 or AN/APG-81.This radar will have a lower detection distance than Irbis-E.[Interestingly, CAC also points out that although Irbis-E is called the strongest PESA, it can only be comparable to F14's AN/AWG-9 in many ways.]

So you think a radar Russia developed over two decades after the F-22 radar will be worse? I doubt it.
Plus Russia supposedly already has the 036M radar in testing. Given when the Su-75 will enter service, later this decade, that radar might be in active service by then.

Su75 is more capable in BVR or air-to-surface than Su57, because of its more stealth design.But it's not suitable for dogfight because of its lower thrust-to-weight.

Eh, no. You have read too much US fanboy propaganda. We don't even know what will be the performance of BVR missiles of both the US and Russia when it enters service.

 

[Stealthflanker]

Calculations done by someone who clearly does not know what they are doing. The IRST dome is transparent to radar. Calculating its RCS as if it was some kind of solid metal ball is idiotic.

Radiotransparent IRST actually make things worse as the radar wave penetrating the dome will basically reflect from anything inside it e.g the pedestal or anything behind it. Thus why there is thin layer of gold, it meant to prevent the wave from entering.

The best thing can be said about Su-57 or LTS's IRST layout is that the RCS is not really considered a problem... and when it does, it has that rotating feature and problem solved. The RCS for the rotated IRST will be lower than when it's "open".

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Su75 may uses Su57's H036-1-01, this is a AESA which completely behind AN/APG-77 or AN/APG-81.This radar will have a lower detection distance than Irbis-E.[Interestingly, CAC also points out that although Irbis-E is called the strongest PESA, it can only be comparable to F14's AN/AWG-9 in many ways.]

This is extremely debateable tho. as nobody knows so far at least what is the TRM rating of N036. Or how the radar operates.

The latter is more important especially for phased array, where it's inherently more flexible than mechanically scanned array, one thing can be done is to actually vary the dwell time in cost of scanning time. The following is my estimates for N036 assuming 10 Watt rating TRM. The dwell time is 0.04 seconds, with total scanning time of 6.5 seconds.



Range for 3 sqm target at PD-50% is 363 km.. while for PD-90% the range where one can actually "lock" the target is 248 km. This is more than the "lower end" of Irbis listed in NIIP site. If one wish to gain 400 Km.. then additional 0.01 seconds of dwell time can be provided in cost that to search the area (120 x 11 deg, correspond to about 7 elevation bars) One needs 8 seconds.

If they can put higher rating TRM, then the range would be much better, especially if they can have better noise factor than Irbis's 3.5 dB NF.

 

[Qian CDer]

In fact, this paper gives a detailed analysis of each problem. But too many professional words make it impossible for me to translate them accurately, and I would appreciate it if someone could give a translation.

Yes I am sure Sukhoi spent many years on an airframe design they knew would not work. You do know there was a competition for the LMFS between Sukhoi and Mikoyan almost two decades ago and this design is probably that old right?

Calculations done by someone who clearly does not know what they are doing. The IRST dome is transparent to radar. Calculating its RCS as if it was some kind of solid metal ball is idiotic.

I think only the head radome is transparent to the radar.So the radar has to be tilted to reduce RCS.In fact,the paper points out that "0.02㎡ RCS" has taken into account the results of stealthy processing.That's why J20/F35/F22 only uses EOTS/EODAS

No it won't. Plus the Su-75 has a much smaller frontal area than the F-35 so it should have a lot less drag.

The paper points out that when the thrust of the engine is 16 tons and the takeoff weight is 18 tons[Including 4 tons of fuel],the thrust-to-weight ratio is only 0.89. This is similar to when F35A is filled with fuel.If there's a big resistance, of course, it's a bad thing.But it's just as bad that Su75 has a lower thrust-to-weight ratio.Thrust-to-weight ratio is important in close-range combat.

Compared with what? This is a supersonic jet fighter not a subsonic ground attack aircraft

This paper does not compare it with other fighters at this point, but points out that the capability is weak.

So at worst it will be just like the F-35 you mean? I would not be surprised if it could do supersonic cruise with the Izd. 30 engine

Yes, the paper thinks that Su75 will be similar to F35 at this point.

So you think a radar Russia developed over two decades after the F-22 radar will be worse? I doubt it.
Plus Russia supposedly already has the 036M radar in testing. Given when the Su-75 will enter service, later this decade, that radar might be in active service by then.

This is very likely.Under the same technology, the number of TRM will affect the ability of AESA, H036-1-01 has only 1552 TRM.[AN/APG-81 has 1676 TRM] There is no inevitable relationship between capacity and age,such as J20/J35 still uses engines that lag behind US for two decades or more.This is similar to the problems encountered by Russia in the electronics industry.As for N 036M, I think it's too early for us to talk about it.

Eh, no. You have read too much US fanboy propaganda. We don't even know what will be the performance of BVR missiles of both the US and Russia when it enters service

At this point, this paper only compares the differences in capabilities between Su57 and Su75.

 

[Qian CDer]

This is extremely debateable tho. as nobody knows so far at least what is the TRM rating of N036. Or how the radar operates.

The latter is more important especially for phased array, where it's inherently more flexible than mechanically scanned array, one thing can be done is to actually vary the dwell time in cost of scanning time. The following is my estimates for N036 assuming 10 Watt rating TRM. The dwell time is 0.04 seconds, with total scanning time of 6.5 seconds.

View attachment 81692

Range for 3 sqm target at PD-50% is 363 km.. while for PD-90% the range where one can actually "lock" the target is 248 km. This is more than the "lower end" of Irbis listed in NIIP site. If one wish to gain 400 Km.. then additional 0.01 seconds of dwell time can be provided in cost that to search the area (120 x 11 deg, correspond to about 7 elevation bars) One needs 8 seconds.

If they can put higher rating TRM, then the range would be much better, especially if they can have better noise factor than Irbis's 3.5 dB NF.

I agree. This paper first points out that when other conditions are the same, the number of TRM will affect the ability of radar,the 1552 TRM of N036-1-01 will make it lag behind AN/APG-81.The paper quotes Russia's claim that Irbis-E is the furthest radar to detect（400km）,then the actual ability of Irbis-E under various conditions is analyzed.Finally, it is considered that N036 will be difficult to compare with AN/APG-81 in this case[The detection distance is closer than Irbis-E].

Considering that PLAAF has bought Su35 and Irbis-E, and that the two authors of the paper are senior engineers and researchers at CAC, I think this is very credible.