For me, problem is that there are in ‘ether’ few real facts, to much fairy-tales…

Only because TsAGI or flight manual data is not enough for you.

For example, I didn’t see F-15’s stall speed ie lift, easily..I had to pay a lot for that info ..CL curve…

F-15C uses NACA 64A airfoil. A simple search on some fluid dynamics books will reveal the CL curve. You wasted your money.

and yet everybody is talking about F-15’s lift or instantaneous turns

Source:
[ATTACH=CONFIG]215978[/ATTACH]

Also I think Hornet has the best L/D of modern US fighters..just thrust deficient, but it can be tolerated. The F-16’s pilots say that 15 is better slow because of lack of alpha limits and possible rudder rolls…at the edge of departure…

F-15 is better at slow speeds than F-16, no one is arguing about that.

Su-27SK is heavy .. I do not know whether its exact basic weight is published in forums and internet…and how can we talk about performances without that info .. and a/c is 25 years old, people are wasting energy debating…

Weight alone has nothing to do with performance. Its the relation of thrust, lift, drag AND weight determines performance. We are not making an academic study. We dont need to know the power curve, CdA and transmission ratio of our car to determine its 0-60 or top speed. We just look at the technical specifications. Same simple logic applies here.

Most graphs are fiction…look at the max speed SL !
[ATTACH=CONFIG]215950[/ATTACH]

That is from LOMAC computer game, obviously fiction.

or how F-15 is better in sustained turns between 700 and 1000 km/h, 200 m altitude ?? (Russian graph, unofficial)
[ATTACH=CONFIG]215951[/ATTACH]

IIRC That is the TsAGI data which compares factual Su-27 performance with ESTIMATES about F-15, F-16 and Tornado. Which are all wrong I may add. It is the same source I’ve posted for Su-27 data.

I’m not saying who is better, I’m just saying that a/c are decades in service and shame is that no useful data are on forums !!

My first graph is from F-15C flight manual. Second being TsAGI data, I can say they are pretty much useful. Its just you who don’t see it.

3rd and 4th graphs are made by me, I just merged two graphs in excel.

I didn’t mean to talk about good and bad guys, now all guys are bad …about hypothetical situations…

I wanted to talk about lift/drag ratio, a/c weights..stall speeds, turn rates, SEP, engine basics and limits…both planes are not new and I didn’t see much of these official numbers on a hundreds of pages in forums, how so ?

At low altitudes, Su-27 has clear advantage in terms of maneuverability. Its obvious to everyone Su-27 has superior instantenious turn rate, but it also has superior SEP and sustained turn rates.
F-15C Sustained Turn rate:
[ATTACH=CONFIG]215941[/ATTACH]
Su-27 Sustained Turn rate:
[ATTACH=CONFIG]215942[/ATTACH]
I merged both graphs in excel and result is interesting. At below ~550 km/h, Su-27 has better STR than F-15C’s available turn rate.
[ATTACH=CONFIG]215940[/ATTACH]
At higher altitudes, Su-27’s design put it in a slight advantage at subsonic speeds and F-15C’s design makes it slightly better at supersonic speeds. Su-27 does have better instantenious turn rate, but the difference is negligable:
[ATTACH=CONFIG]215939[/ATTACH]

At 1000 m altitude, Su-27 accelerates from 600 km/h to 1100 km/h in 15 seconds.
Interpolating F-15C charts, F-15C accelerates from 600 to 1100 km/h in ~13.5 seconds.

Su-27 has max instantenious climb rate of 300 m/s at sea level.
F-15C has max instantenious climb rate of 304 m/s at sea level.

Su-27 is peacetime limited to 8.5Gs M0.85.
Both aircraft is capable of pulling more than 9Gs as they are not hard limited.

Su-27 is capable of level flight at 200 km/h

At sea level, Su-27 has 1400 km/h and F-15C has 1440 km/h max speed. They are not time limited.
At altitude, Su-27 has M2.35 max speed. Speeds from M2.15 to M2.35 is transient and limited to 5 minutes.
At altitude, F-15C has M2.5 max speed. Speeds from M2.2 to M2.5 is transient and limited to 1 minute. With CFTs, Max speed is limited to M2.0
On Su-27, missiles on pylons 5,6,7,8 has no impact on drag. Adding further missiles on pylons 3,4 will reduce Max speed to M2.2.
On F-15C, missiles on pylons 3,4,6,7 has no drag index if mounted conformally (as 3C,4C,6C,7C)

Higher Wing load does not allways mean lower agility.
There are many example of this. And the physical size and shape of the wings is pretty much the same on both Su-27 and Su-35S. Only difference is reenforces internal structure, improved welding method and made possible with stronger alloys too.

Su-35S has a improved FCS, larger Vertical Stabz control surface, and much higher T/W ratio. Its a no brainer.. The Su-35S outperform the Su-27

Everything else being equal, it always mean lower agility. Wing with exact same geometry will produce exact same lift, however higher weight will decrease the available G load.

For example Su-27S will have max ITR of 30,2 deg/s at 600 km/h, by pulling 9Gs.

As ITR is limited by wings stall AOA before G limit, the point it reaches 9G limit also gives us an important info: A Su-27’s planform will produce a maximum of 1854 kN (21000kg(weight)*88.29(centripetal accelaration)) of lift at that under these conditions. Lets say Su-35’s mass is 2 tons greater, it would only pull 8.22Gs at same speed & altitude.
so at 600km/h it will have 27,5 deg/s ITR.

However, aircraft would not be reached the 9G limit, I interpolate it should be able to pull around ~29.31 deg/s at ~618 km/h, which is still excellent, but inferior to Su-27; more than that, its available turn rate graph will always be below Su-27’s, meaning at a given speed, Su-27 will be able to pull a harder turn than Su-35 throughout the envelope.

As for sustained turns, it would require a lot more complex calculations which I am not in the mood right now.

Gripen C is said to have frontal RCS approx. 10% of F-16, which would put the Gripen C around 0.1m2 — given all the work Dassault has put into reducing RCS of Rafale it seems reasonable to assume that it’s around 0.1 m2as well, and this seems to be supported by the claim that Rafale has around 10% RCS of the Mirage.

However RCS will most likely go up with external munitions — how much is impossible to say. I recall Saab stating that the most effective way to reduce RCS of Gripen NG was to replace the AMRAAM with Meteor (or was it replacing Sidewinder with IRIS-T? I always forget). With low-RCS pylons and a low-RCS missile, the total RCS may still be pretty low.

During an exercise with Polish airforce, two MiG-29 9.12As (Flying cap) fired on Blk52+ F-16 (flying escort for Su-22 bombers) at 80 kilometers, R-27R missile’s max range. Given that, they must have detected, tracked, and locked on F-16s long before that. This conlcudes either N010 radar is a technological marvel -which is clearly not the case- OR an F-16 has A LOT larger (read: 5+ times larger) RCS than just 1 m2.

Still, a strong radar can detect at a distance — however I suspect that to detect Rafale at large distances the Su-35 cannot operate its radar in LPI mode but may need to increase the power significantly.

IF that is true for Su-35, that its ALSO true for rafale to detect Su-35. (less powerful radar vs bigger RCS).

Thus it becomes easy to detect the emissions for the Rafale. By sensor fusion and triangulation a group of Rafales will then be able to arrive at a firing solution, and probably before the Su-35.

WHAT sensor fusion are you refering? Radar, IRST, Datalink, RWR are also present on Su-35.

Putting range figures aside;
-Irbis has 20kW power output. RBE-2 has 838 modules * 8watt = 6.7 kW. (3 times power output)
-Irbis has 6647 cm2 area RBE-2 has 2827 cm2 (2.35 times greater antenna aperture)

Assuming same PEmin (minimum power return that radar can distinguish from background noise) for both radars, and equalisin Rmax for both radars (ie both aircraft be able to detect each other at same range) Su-35 has to reflect (2.35^2 * 3) = 16,58 times more power (Pr) to be detected, ie, it needs to have 1658% RCS of the Rafale.

Now like everyone else here, I have no solid data on RCS of Rafale or Su-35 (or M2k F-16 Grippen or anything else for that matter). But believe there is no way a Rafale could have just 6% RCS of Su-35 in any scenario (armed, clean, with or without EFTs etc etc).

I do not know real Rafale RCS (in dB), but… A certain level of observabilty was a requirement from DGA when project started. And fulfilled. So one could think that Rafale was designed (and shaped) with a relatively LO in mind.

I’m not disagreeing on the fact that it has relatively more LO features. It may have 1/2 to 1/3 RCS of Su-35, I don’t disagree about that either. But when someone claims it has 1/100 of Su-35 (10 vs 0.1 sqm frontal RCS… right…) it gets pretty much laughable.

And what I am trying to say is having 1/3 or even 1/4 RCS of the other aircraft has exactly NO use. Because detection range changes with RCS ^ 1/4

Irbis has claimed 400km range vs 3 sqm targets. Lets assume 2/3 that range for tracking. If so
10 sqm target can be detected at 540 km, tracked at 359 km
5 sqm target can be detected at 454 km tracked at 302 km
3 sqm target can be tracked at 266 km
1 sqm target can be detected at 304 km tracked at 203 km
0.5 sqm target can be detected at 255 km tracked at 170 km
0.1 sqm target can be detected at 171 km and tracked at 114 km

For any logical assumption, Rafale’s detection range will be around 454 km to 304 km, and tracking range will be around 302 to 203 km.

The Su-35S is more manuvereble than any Su-27. I’m not talking about TVC.
Just plain more Kenetic, acceleration, climb and higher speed around the corners.

It might come a little more heavy, but the improved FCS and 4000kgf of extra Thrust makes this a Hot Rod. and It has allready been established that it can fly higher than Su-27.

is it??

https://www.youtube.com/watch?v=n_4WBQDtQ70 (starts at around 3:30)

I can agree about climb and acceleration. However it doesn’t have higher speed or kinematic advantage during instantenious or sustained turns. With higher wing loading, it wont reach same ceiling.
at 4.30 point mark, Su-27 completes a sustained 360deg turn in 14.59 seconds, which would translate into 24,67 deg/s turn rate. Not only that, it also maintains a very high energy state and climbs vertically while doing barrel rolls. Personally I have neither seen an aircraft completing a full 360 turn that quick, nor doing vertical barrel rolls after a full 360 deg turn.

A couple of things , the Rafale is 4++ gen fighter and while not being a LO aircraft , it has some very important features to reduce its overall RCS . I am not going to describe them all as it would need a rather big post and numerous pictures , pdf , etc , so please spare me and don ‘t ask me to post it , thanks . Suffice to say that what Dassault said years ago about its RCS clean is true and can be trusted .

For you maybe. I for one don’t get why Dassault is more trustworthy than Sukhoi.

What I contest is the true work done from the Su-27 to the Su-35 to lower the overall RCS . What did they do ?
-1) they used more composites in the airframe (what % of the overall airframe is made of composite ? How much more from the original Su-27 ?)
-2) They worked on the inlets , the basic solution has been to apply ferro-magnetic radar absorbent material (RAM) to the compressor face and to the inlet duct walls . A layer of RAM between 0.7mm and 1.4mm thick is applied to the ducts and a 0.5mm coating is applied to the front stages of the low-pressure compressor .

So in otherwords, intake and compressor face is made low observable to reduce frontal RCS. What did rafale designers do other than this?

The result is a 10-15dB reduction in the RCS contribution from the inlets.

Without knowing exact RAM qualities or the amount of composites how can you remotely be confident about this number?

And that ‘s it . The frontal RCS of the Su-27 is given at around 12 m2 .

Is given by whom?

Until I have some better numbers , let ‘s say that they increased the composites by 10% (see the empty weight of both aircraft , Su-27/35) , resulting in a more or less 5dB reduction in the overall RCS , plus 10-15dB reduction for the inlets. That gives us a overall frontal RCS of around 8-10 m2 , clean

And you’ve just shown everyone how poorly you are making up numbers.

RCS in dBsm = 10x Log10(RCS in m2)

Assuming Su-27 truly has 12 m2 RCS; it gives 10,8 dB of RCS.
You are estimating 20 dB reduction in RCS, which would make -9,2 dB.

RCS in m2 = 10^(RCS in dB/10)

Your numbers conclude Su-35 has 0,12 m2 RCS. LOL, you just made the Su-35 a stealth fighter.

As i said you didnot understood. Su-35 will be at 60k feet. it will be looking in look down mode. it will lock on both Rafale and fire RVV-BD. once RVV-BD are fired. It will even accelerated further towards the target at speed greater than Mach 2. Rafale is not stealth plane that it can hide. and certainly does not have Growler like capability to jam Su-35. Even the video you see Su-35 does not turn back after firing the long range missiles.

these gaint pods are integral part of Su-35 see the right pix. Its aerodynamic performance is designed for that.
http://www.knaapo.ru/rus/products/su-35/index.wbp

First, NO aircraft other than MiG-31 will even approach to 60k feet. I will not go into physical reasons of this rather laughable claim, but suffice it to say Su-27 manual does not even give any performance data above 12000m. This graph should help you when estimating “what would Su-35 do” in various scenarios.
[ATTACH]213300[/ATTACH]
Translates as:
Fig.19 Flight profiles during interception of aerial targets
Включение форсажа = enable afterburner
1-2 interception of nearby targets in stratoshpere (climb to 11000m, dry thrust only)
3-4 interception of far away targets in stratoshpere (climb to 11000m, use afterburner, switch to dry thrust during engagement)
5-6 interception of far away targets in average or low altitude (approach at 11000m, use afterburner before and during engagement)
7- interception with limited detection range.

Second, 2 vs 1 scenario includes dozens of variables, and during engagment 2 fighters won’t be flying in formation. Even a good old ALQ-119 pod can jam Irbis or any other radar, provided its far enough from the radar to overpower it. Spectra jammer at 300km range should not have slightest of difficulty in jamming the Irbis. (by the way, lower semi-sphere detection of targets is always more difficult, and would make the jammers job even easier)

Key factor here is Su-35 will be aware of presence of one Rafale, but not the Second, because only the first one will be jamming.