But if you don’t have any clear data on this, than the empty weight +-16380kg is standing AFAIC.

Feel free to take any data that fits your needs.
Don’t be bothered by reality.

Tanks for the input.

Well the Su-35 have a normal weight at(2 x RVV-AE + 2 x R-73E) 25,300kg.
Don’t know if this is fully tanked..

But in a empty/dry weight the Su-35 actually lighter than the Su-27 Empty weight: 16,380 kg (36,100 lb).

I’ve seen it someplace that it was about 400kg lighter, but i have trouble finding it..
Do anyone have any thing on these matters?

Actually, it is heavier.
Besides: 16380 will probably be the empty empty weight, operating empty weight is normally plus additional 5%. I usually add that to weight data, if they are not directly from the flight manual.

Keep also in mind that this is only the prototype so weight could very well change on the production series!

Empty weight knows only one direction: upwards.
See: all aircraft.
Just the added heavy pylons and all that stuff.
See F-16E compared to A or F-15E to A.

Expect to come out close at 18t empty, maybe even more.

Yes, but the question is how far UP on the supersonic regime?You mention beyond M1.8?
There is a limit somewhere in the supersonic regime for the AL-31F engine.

The engine actually doesn’t know how fast it is. The air arrives with same speed all time, and without distortion and other stuff. At least it should be like it.
The design point of the inlet is pretty much not of interest. Fact is that the whole airframe was originally conceived to fly either in subsonic cruise or fly clean supersonic, means above M1.3ish. In between is the world of pain, which is never considered for sustained level flight. Pressure recovery and stuff is consequently also optimized.

Putting in more thrust might push it a bit in dry thrust, but in the end it doesn’t bring you the additional speed with acceptable SR (and that is what it is all about).
Finally, more installed thrust have drawbacks: higher fuel flow, less desirable SFC in many occasions. Actually, I think they have more thrust on the Suchoi 35 to keep performance levels of its predecessor. The 35 gained about 2 or 3 tons over the vanilla 27.

True but it is still a question of choice dictated by Russian (or USAF) requierements.

On the other hand F-22 is also carrying all its fuel internaly for its current missions, also requierements.

In all i think there is little need to argue which solution “is better”, since they both have plus and minuses i think it is a matter of what a customer needs rather than which is better…

True, detailed mission analysis can show ups and downs.
In case of most Western aircraft, they are seized by air combat missions with moderate radius. Later, existing airframes are used and missions extended.
I think the approach is efficient as the engines normally have quite a growth potential and some other limitations may be eased (field performance for example).
When one puts weapons load versus empty weight, an F-16C is quite remarkable. I guess the Rafale doesn’t come out much worse, potentially even better.

The Suchoi 27 was specifically designed for a unique requirement and as such pretty unique. It now serves in many air forces as it is the better 4th gen aircraft of the Russians, but still, for most users it is quite a heavy bird (except those that specifically use the multi-role options).
Most nations could use a Mirage 2000 for the same mission, without a big loss in radius.

TWR is only part of the equation as the opposite force to drag but you can have as high a TWR as you want even if you manage to supercruise it won’t be effiscient BOTH aerodynamicaly and at fuel effieciency level (F-16 at M 1.1).

BEST example is the F-102:

Aerodynamics are a MOST for supercruise and the AVON Mirage III doing M 1.3 in 1963 didn’t have Typhoon’s TWR but instead, boosted a 60*3 sweept leading edge combined with a 3.5% thickness ratio and a 1.98 aspect ratio…

This allowed it to fly faster than BOTH Rafale and Typhoon with a much lower TWC (Atacr 9C) and reach M 1.3 in military power although of course in clean configuration due to a much more “compressed” transonic region and lower supersonic drag polar.

Now compare the wingplan of F-22 with that of a Rafale and remember that the Raptor’s wings generates VORTEX lift just like any delta wings (NOT the case of F-35 BTW).

Its Supercritical (NACA) wing profile is actually DRAGGIER than a laminary in supersonic but there is your TWR working to its favour once passed the transonic region and its DRAG peak.

Since once passed the transonic region the drag polar actualy goes DOWN it doesn’t make much difference at these speeds to use a supsercritical profile.

If F-22 wings weren’t sweept at near the same value than that of Rafale (48*) it wouldn’t be supercruising this fast and this is also the (main) reason WHY F-35 doesn’t with BTW a higher TWR than a Rafale M88-2 E4…

Sorry we lost some class in this thread.
I am partly to blame.

Anyways, what you are saying is true.
What I tried to say repeatedly is that the reference thrust level (from Wikipedia) doesn’t give away anything about the ability to supercruise. Of course, a thrust-weight ratio close or above one indicates it might be possible, but the drag is the key feature. And this drag, no one is able to guess. We are talking about 5-10% that make the difference.

In any case a typical CRUISE speed in heavy configuration for the Rafale would be M 0.83 at 89% throttle settings.
This gives you 1.000 Nm+.

Thanks for that info, I guess it is two or three tanks retained, normal reserves optimum cruise altitude.

Funny questions, to find the Drag Coefficient in ANY aircraft takes a lot more than we can gather without manufacturers classified datas and proper simulation softwares (I got this but no datas for feed into it) but at least we can define thrust accuratly or nearly at every possible Mach regime.

Exactly, we can get some drag data of contemporary aircraft if we dig deep in many sources (books, Nasa Technical Reports Server, etc). But the accuracy is always limited. Besides basic characteristics, details are important for stuff like supercruise. Predicting drag from external stores is pure hell, basically guesswork.
Engine performance is not that simple, either. We have different inlet types, but they don’t really make a difference before M1.5ish.
See here the approximate performance of the inlet of the F-16:
[ATTACH]168386[/ATTACH]

An aircraft like a Suchoi 27 derivative would need to go through a big design change to become a true supercruiser. And: being supercruisy doesn’t help you all the way: it means penalties in subsonic. An aircraft that gives no consideration to supercruise (neither engine nor airframe) and relies completely on the might of its afterburner to become supersonic, will be more efficient in subsonic cruise when design is done right (which normally is the case).

The redesigned engine involves increased AIRFLOW which in itself is a sign of limitation in military power output in regard to supercruise…
The curent EJ-200 and M88-2 E4s have the same issue with a pressure recovery limited to Mach 1.3 without increased airflow…

That is interesting to read.

I am not familiar with the Russian engine types though only the technical aspects of the design and their effects on aircraft performances.

A thrust-mach table (dry thrust) for the AL-31 gives some indication how an average turbo-fan looks like. The data is uninstalled thrust, at least I guess so.
[ATTACH]168387[/ATTACH]

This chart shows actual drag (in units of force) and thrust. It is – I assume – pure hypothetical and does not represent any particular aircraft (and if potentially something like the Concorde or so).
[ATTACH]168385[/ATTACH]
“Supercruise” means to optimize the aircraft, engine and inlet for the Mach region between B and C.
Anyways, as can be seen on the actual drag, the needed thrust is massive and SFC in dry steadily increases with Mach number. So, we will see a huge drop in specific range, and given the mission considerations it can easily become a simple show-off. Why being 30% more efficient for a few minutes when I save weight and drag?

That’s a bunch of crap.
Again, why can’t the Su-35 make supercruise with a light A2A config.
Plz try to give an proper answer this time?
Sobering will get us nowhere..

Proper answer:
Thrust < Drag.

Ok, lets leave out the “post stall”.
I said the Su-27 have the stabillity to recover faster from a stall than the Su-27s counterparts.

Suffering a stall during ACM is deadly. If your direct opponent doesn’t kill, his wingman does.

But, what would happen when the altitude gets to low?

Turning until the altimeter hits the lower stop is stupid, no matter what aircraft you are flying, in what era. The sustained turned show-off combat has nothing to do with reality. The potentially slightly better sustained turn performance of the Suchoi 27 (my graph above showed otherwise, but let’s assume for a second) won’t help much, if at all.

In the real deal. Who break off first? Who looses most speed and stall? And if they both go into a stall, who recover fastes?

Excess lateral stability has nothing to do with stall recovery. By the way, the Suchoi 27 has an AOA limiter, technically it shouldn’t stall but limit load factor, which could be bad news for the pilot (if he isn’t smart).

Stop twisting my questions around. You don’t have to lecture me about JHMCS and missile capabillity and all, i was adressing the stabillity on the Su-27 vs other aircraft..

Sorry, but your understanding on this topic seems limited.
You’re mixing lateral stability with stall recovery.
I am not twisting, I am actually the only one giving you answers.
But if you don’t like them, feel free to open a thread which will only hail the Suchoi 27, I promise not to post in it.

The Su-27 design for its role are far better concived, than the F-15 with its droptanks on.
Sure there are some drawbacks with the Su-27 design too.
But in the large picture for a heavy fighter/interceptor(or what ever you want to call it) role like Su-27 and F-15,
i can only see Su-27 coming out on top.
(On droptanks vs more internal fuel that is!)

You hit the point by using “heavy”.
The Suchoi 27 is a heavy fighter, while the F-15 is a medium one.
Now both have roughly same performance (payload, range, maneuver), with the difference that the F-15 carries drop tanks on its way to the actual place of action.

For the classic counter-air mission the Suchoi is less well designed than the F-15, arriving in combat heavier and larger, at the same time being more costly.