Again this is debatable, as it depends upon mission as shown in my edit post…Even in the article from 2006 we can only draw a ROUGH speculation because the exact range is protected/classified…Until we are told official fuel burn data its tough to extrapolate useful supersonic range…It is frustrating but we really need to know how much more fuel is burned at mach 1.7 compared to mach 1.5 , or mach 1.5 compared to mach 1.2 etc etc ….Estimating the supersonic range of the F-22 is a RISKY proposition unless we are simply GUESSING…

Since you are pushing the Mach 1.5 supercruise range issue, from what limited has been revealed by test pilots, there was a suggestion based on AW&ST, June 12, 2006 that a typical anti cruise missile defence mission the F-22 could Supercruise @ Mach 1.5 for 41 minutes..which would roughly translate to around 650-700 Miles as determined by TOAN…

(Sorry to jump in to your discussion) However, we can estimate the usefulness of supercruise by comparing to other aircraft performance at same speed (M1.5)
PW-229 engined F-15E with CFTs 4x AIM-7s and 4xAIM-9s consume 500 pounds of fuel per minute at M1.5, 50k feet. It has roughly 24000lb fuel capacity, so it can spend 48 minutes at that speed. Obviously, you may say it would also require fuel for take off, climb and acceleration, but F-15E can use 3x drop tanks for those tasks, or it will have a slightly lower supersonic range than F-22.

The real thing is, F-22 achieves this perfromance with 14000lb fuel, F-15E matches (or approaches at the very least) F-22 with 24000 lb fuel.

You guys are really ‘tough’ … First graph can be called “sustained” climb graph, climb w/o bleeding true-speed. Any trainer can climb 250 m/s M 0.9 SL, but with speed bleeding – instantaneous climb. If a/c has climb or SEP =0 that means it also could not accelerate any more and it’s speed is max one.

Next..these russian graphs are not particularly precise, MiG-29 surely can not go faster than 1.2 M SL or 1.15 more precisely.

What is “tough” is that your inability to use graphs properly. So you also claim MiG-29 can sustain 325 m/s climb rate?

You are looking for max level flight speed at a given altitude. You dismiss level flight envelope graph and level flight wing lift graph and take **instantenious** climb rate graph to assume max level flight speed. Excellent!

You say Russian graphs are not precise, and you manage to find the only graph in 900+ page manual that speed ends at M1.1. However more likely scenario is MiG-29 is not tested above M1.1 for climbing as it would be utterly pointless. Russian graphs are more than precise where it matters the most, that graph is meant to show climb rate. You are possibly the only person in the world to use climb rate graph to get maximum speed.

Its inlet/engine case/comb.chamber pressure limit is reached at 1500 km/h. That means it is a somewhat slower than that !! Because of sharp thrust drop! No dreams about M1.25 or Su-27’s 1.3 M.

Nonsense, one after another… What sharp thrust drop? Mach number is dimensionless, compressibility at same Mach number S/L is the same as 50k feet. If that were true same shart thrust drop would also occur at 40k feet, and would have similar airspeed limitation. You are tell me to read engineering magazines, yet you do not have a clue about something that is thought at the 3rd day of fluid mechanics course.

And you claim a multi shock variable inlet pressure limit reaches at 1.15? Laughable. As far as inlet/engine perf concerned, even NSI inlet of F-16 would have ZERO problems exceeding M1.15 at sea level. But with such bias towards MiG-29 and Su-27, I would expect you to claim F-16’s inlet design is actually superior to those types.

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Purpose of this graph is to show speed limit at different altitudes, and it clearly shows the difference between reached speed and allowed speed at 14000m altitude (M2.1 vs M2.35). As it shows no such difference at S/L, it 100% surely can reach 1500 km/h (M1.21) at Sea level. Questioning this by nitpicking small details from graphs which has ZERO relation to max speed is childish and utterly stupid.

Every a/c is alpha limited until g limit.

Alpha limited but not MAX alpha limited. You can also say a/c is alpha limited through the envelope in order not to exceed g limits. There is a big difference in those claims. Take F-16 for example.

Su-27 graph I attached is for TVC version that is as slower as altitude is higher.

What TVC has to do with max speed? Are you drunk?

As I have said Su-27 can pull 9g at the weight of 19.ooo kg, it is not the weight that can be compared to other a/c’s combat weight, because it is far lighter. It empty weight is 17.200 kg !

First, either you didn’t read what I have wrote a few posts above, or matter is really beyond your understanding. To summerize AGAIN; You are comparing pilots handbook G limit of Su-27 with G limit for combat performance, from supplemental manual.

Compare apples with apples; From that analogy, IF Su-27 has 8G limit at 21.4 tons, then F-15C has 7,33G limit at 37000 pounds. IF, Su-27 can only reach 9G at 19 tons, than it doesnt matter, F-15C is still limited to 7,33Gs at 30000 pounds.

Secondly, baseline Su-27’s empty weight is 16.3 tons, just as baseline F-15C is 28000 pounds. If you take different versions, thats a different story.

Interestingly official USAF comparison with MiG-21 states that MiG has advantage at very high AND VERY LOW speed range. What is your explanation ?

Compared to what exactly? Compared to F-16 for example it has no advantage throughout the flight envelope.

From the book test pilot V.N.Kondaurova “The runway of a lifetime.” The head of the comparative tests on F-5E with the MiG-21bis and MiG-23M.

An excellent example how misleading raw data can be when it comes to the reality test for a given situation.

[QUOTE=Sens;2024618]There is nothing more serious than a real adversary combat to learn about the practical gains from a design. In that very case the ones involved on the Russian side hard a hard time to explain the outcome. In that very case it was the lift behavior from the wing-design of the F-5 at subsonic speed (

Yes, lower wing loading, but still better than the FLANKER! Generally that article (written by me) is pointing at the hi-hi (comparative) weakness of the JF-17, (high altitude, high speed), basically f-pole BVR fights. The JF-17 trades-off that high altitude BVR performance for excellent WVR in mid-low altitude. (or so I would surmise given the data).

Lets compare apples with apples. You cant just take raw data (Wingloading, T/W, ITR, STR ..etc) for their normal take off weighs and compare them. When equipped for same mission (same payload and fuel for same range), heavier types like F-15 and Su-27 would always have kinematic advantage over lighter aircraft.

For example, Su-27’s normal take off weight include 4 missiles and fuel for 1500 km combat Radius. If JH-17 were to reach its 1352 km max combat radius (which does not even match Su-27’s NTOW combat radius), it would need full internal fuel + 800l centerline tank + two 1100l wing tanks. I wont do the math for this as limitations are pretty obvious.

JH-17 has 371 kg/m2 wingloading at its NTOW, which includes fuel for ~750-800 km combat radius and 4 missiles. If Su-27 was to be loaded for same mission, it would only need to carry less than 50% fuel, which would translate to 21400 kg take-off weight and 345 kg/m2. Similarly its T/W would be 1.17.

We are spending time and forum pages irrationally …..

I’m not saying F-15 is more maneuverable, my conclusion is opposite, I just crossed manuals, it takes some knowledge and effort !!
Other thing is if you wish to say that F-15 manual is wrong, if you say that USA is fake country…

I never said that. Instead, its you who repeatedly try to dismiss Russian data.

Andraxxus, you are aware that Overload warning system graph is not applicable in calculation of max instantaneous turn,[/QUOTE]

I have never said that either. Re-read my post.

for example, your graph shows that F-15C’s 9 g !! (a/c is recertified for 9g) corner velocity at SL is about Mach 0.9 ! That means turn rate of 16.4 deg/sec, stall speed of 369 km/h and max CL = 0.5 !!

Wrong, that graph cannot be used to interpolate entire CL curve. but if you want to analize that graph;
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Earliest point where F-15 can achieve 9G is at M0,62. Translates to 23,62 deg/s ITR.
Lift force = 9G*16780kg*9,81m/s2 = 1481506N = Cl * 1/2 * 1.2 * (212,86)^2 * 56,5 m2 You can find CL to be 0,964. Without knowing exact AOA, or any other point where aircraft is AOA limited (rather than G limited) you cannot go further than that (in terms of finding the CL curve. You need multiple points for that)

If we assume this is the best available AOA and Cl = Clmax, stall speed is 16780kg*9,81m/s2 = 164611N = 0,964 * 1/2 * 1.2 * V^2 * 56,5 V = 70,9 m/s = 255 km/h. However this excludes the use of flaps, or engine thrust will have a vertical component on high AOA.

You may ask why we used the earliest 9G point. Thats because this is the point where aircraft is both AOA and G limited. We require AOA limited section to find CL.

F-16 is 15 deg alpha limited for corner speed because at these speeds dyn, directional stability is far lower than at low Mach. Other graphs can show deceleration at instant. alpha. As Mach increases Su-27’s limit alpha is also lower.

Not true, there are dozens of more reasons involved about F-16, which offtopic and I dont want to get into those. Remember I said F-16 is the only fighter with 9G limit throghout the envelope, that has a different set of limitations? Su-27 is capable of pulling its max AOA of 25deg at 9Gs at ~M0,48 (600 km/h). After that, aircraft is G limited and AOA limit goes down in order not the break the airframe. Same goes for MiG-29 and F-18C also.

However thats not the point. Point is, you dont make high AOA turns to complete a full 360 turn more quickly; you stick to somewhere between your STR and ITR.

Nonsense in your “Nonsense! F-15/16 MiG-29 Su-27 etc are all limited by their cockpit glass in terms of low altitude topspeed”
Cockpit transparency is limit at Mach 2+, you can calculate stagnation temperature easily. SL limit is structural strength – flutter.

MiG-29, Su …can not exceed M 1.15 at SL in level flight, see graphs. Applicable for all other planes except US 15/16 with the latest DEEC engines.

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The chart from the F-16 manual you have posted (block 30 to be precise) shows F-16 has positive specific excess power at M1.15 (see where 0 FPS and 200 FPS lines intersect with max speed line), clearly indicating it has thrust to exceed M1.15.

You are missing the point: You said the graph is childish and invalid because Su-27 does not have enough thrust to exceed 1400 km/h. I say even F-16 has enough thrust, and the graph you posted confirms it.

My favorite: F-16 and Su-27. Because they are 40 year old designs, yet they can still hold up -and possibly win- againist anything flying out there.

Sorry for the rather late answer;

Guys we are off from subject ! Do not waste time and these characters….
First, let me wish you all Happy Worker’s Day – May 1st (no matter in how anti-peoples countries we are living) !! In Croatia it was beautiful Holiday until the country was sold.

G limit of Su-Sk is 9g at 19 tonnes weight (w empty is 17.2), 8g at 21.4. At w=22.8 limit is 7.5 for certified service life, a/c will not crack at 9g but life would be exponentially shorter, as in any other a/c..you can not play with certified limit ! How it is cleared to 8.5g at combat weight? I assume combat w is 1.33 X w empty. I do not understand what is not clear to you.
I compared it with F-15C at 39.ooo lb weight, official w with half fuel and 4 AIM-7.
You all guys should not talk about a/c without exact empty weight !
These flight manuals are not written for fun !!

I do not what is not clear in second your (russian official) graph. It says that limit is 8g with 4AAMs and half of NORMAL fuel load (w=21.4), that weight is bellow usual standard combat weight for fighter comparison.

What is not clear is the understanding of G limitation. No “9G Fighter” (apart from F-16, which has different set of limitations, I won’t get into it) has 9G limit at all times. Also, there is an generalized G limit (in US terms, its found on -1 or NFM-000 manuals) which only considers airframe weight and airspeed. And then we see a more a specialized (combat) G limit (which is found on -1-1 or NFM-200/210 manuals) which also gives a G limit with relation to payload, altitude etc. I will refer to F-15 manual to make myself more clear:
You are referring to this graph as basis of your assumptions about Su-27’s G limits (found on aircraft limitations section):
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What is equivalent to this graph on F-15 manual is this, found on Section V operating limitations 5-10:
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If I were take this graph, I would wrongly say a clean F-15C has 7.33G limit. At 39000lb, it goes down to 7G, and only 4G is allowed at 68000lb. This assumption is wrong, because this graph neglects to mention speed, altitude and payload. (Just as the previous Su-27 graph neglects to mention altitude and payload)
However, If we look at the Section 9 Combat Performance A9-12 on the very same manual we will immediately see this is not the case:
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The thing is, these graphs are NOT in conflict. If you look at both graphs carefully, first graph takes the worst case G limits at transonic speeds @ 20k feet, drawing G limit with respect to aircraft weight. In a sense (for a clean F-15C), first graph simply says airframe will not break if you do not exceed 7.33Gs at any time . Second graph adds to that info, by taking speed and altitude into consideration.

On Su-27 graph, it guarantees at 21.4 ton weight, aircraft will not break at 8Gs until M0,85 at any altitude or payload. Unfortunately, we dont have a precise version which takes altitude and payload into account.

If I were to draw G versus speed graph independent of altitude for a 39000lb F-15C, (just like Su-27 graph), it would be like this:
9G at M1,4

Unfortunately that would be next to useless if we were to discuss maneuverability, and actual G limits. If there is a difference between SK manual and the data you try to dismiss, its pefrectly understandable as same difference exists on F-15 manual as well.

Next: you extrapolated CL from sustained g curves to get CLmax for building instantaneous g curve ??? For both Su and F-15. If you do not have exact F-15 lift curve vs Mach you could use this official graph. Official does not necessarily mean true because one can find that max usable lift from this graph does not take into account huge buffet limitation at M> 0.9 !!!!

No, I said I can find CL curve by using instantenious G curve.

Max lift, F-18’s also for example, is achieved with wings stalled. You should read engineering magazines.

That depends. F-18C reaches CLmax at 35deg AOA before stall. Surely, it wont need that much AOA to reach max lift limit at high speeds. I dont think what you claim can be true anyway, please source it.

Your third graph shows IAS limit 1400 km/h, right. But I still say graph is childish because it show that although IAS limit is 1400, Su have enough thrust to fly 1600 km/h level !! That class of a/c can not achieve more than M 1.1 to 1.15 in level flight – because of thrust – drag relation.

Nonsense! F-15/16 MiG-29 Su-27 etc are all limited by their cockpit glass in terms of low altitude topspeed. F-15 manual shows -220 engined F-15 can sustain up to 6.6Gs at M1.2 sea level. (-100 engined ones suprisingly cant reach M1.2) F-16 blk50 manual shows it can sustain 10deg/s and have 300+ FPS positive excess power at sea level when its top speed is reached. MiG-29 9.12 manual shows it can sustain 5Gs at 1400km/h. These ALL indicate they can go FAR faster than their allowed top speed.

In youtube videos turns are not sustained or instantaneous, but combined ! Engines are usually tweaked for more thrust.

Obviously, but an aircraft has to sustain a turn for 360 degrees to complete a circle. Goal is the same; if one aircraft performs it quicker I would say it is better. Engines can be tweaked, but same would go for any aircraft participating airshows.

Andraxxus, you are very good but point is not to wast our time… incidentally I’m flight operations engineer and I take my job home…
You said: “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.”
Problem is that “famous” TsAGI graph is pure fiction probably made by some enthusiast. I have already said that aviation fans should ask for official data ONLY. I’m not surprised that I’m the only one, as you had said, who don’t see usefulness of that graph.
First look at the graph reveals that a/c has 8.5 g limit. Su manual says that a/c has limit 8 g at a weight of 21.400 kg !!!

Wrong. Su-27SK manual says G limit can be founded by mass*PuMAX = constant = 171000 kg, with PuMAX not exceeding 9Gs. While it DOES correspond to 8Gs for 21400kg -which manual consistantly assumes normal payload-, it is *NOT* the G limit of the airframe. Its the G limit with 5100 kg fuel on board.
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To be compared to F-15C, Su-SK needs weight of about 22.850 kg, and that gives 7.5 g limit !!! That’s just the beginning.

PW220 engined weigh 13600 kg empty. Graph is for 37000 pounds so that F-15 only carries 3180 kg fuel. To be compared with it, Su-27 only needs to weigh 19480kg. If you are comparing with NTOW, F-15C should weigh 44000 pounds.

As for your logic for declaring the curves as fiction, its laughable. You read a 8G value from the SK manual and you take it as fact -which is not, as explained in the very same page-, but fail to mention the graphs a few pages ahead where clearly shows Su-27 can pull and exceed 9Gs with 4700 kg fuel and 4 missile payload, where its suggested limit is 5.5Gs.
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F-15’s wing profile is modified and cambered 64A…and that’s just the profile, nobody can extrapolate whole a/c lift from that,

Overall CL can be extrapolated from G versus speed graph if we know aircraft weight and wing area.
Lift force = G*aircraft weight = CL * (density of air)/2 * (airspeed)^2 * wing area.

especially if in max inst.turns wings are stalled and fuselage gives CLmax !

That would be a idiotic form of engineering. Still, irrelevent if we are looking for overall CL of aircraft.

As I have said you guys aviation people, you should ask from your pilots, manufacturers, military…real facts if they want you to be fans of their planes.

I am not fan of Su-27. Maybe I am a little biased towards F-16, but even that does not come before technical specifications.

I wonder if, for example..there is any useful data on Typhoon or Rafale, Gripen..performances in media. And yet everybody know they are the best planes ever ! And Russia gave everything about their best planes ! Who is cheating whom !

Agreed about that. We have enough solid numbers videos etc etc to compare legacy types of Su-27, F-15, MiG-29 or F-16. But not for the types you mentioned.

However if you like to question the validity of the numbers -which are generally considered valid-, its up to you to disprove them. You will possibly say its also up to me to prove them, so I will try my best:

Next, it seems that Su can fly level at altitude of 200m at a speed of about 1600+ km/h. Curves are fiction. It is certainly not official Russian graph. Sorry that nobody has complained for all that. You had better not merge these graphs, in excel

you are looking at page 33 which only shows G limits. Take a look at page 36 also, it clearly shows 1400km/h speed limit:
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The TsAGI data assumes a) 50% fuel load which is 4700 kgs b) 21000kg take off weight. This is inline with 16300kg empty weight + 4700kg fuel. With this weight it should have 8.15G limit according to SK manual. They may have rounded it up to 8.5, IDK how exactly formula should be used (171000/21400 gives less than 8Gs anyway)

http://www.youtube.com/watch?v=4B00eSuLq0Q at the turn starting 4:25, Su-27 completes full 360 turn in 12,7 seconds, averaging at 28.3 deg/s turn rate. That turn made right before the landing, so lets assume 500kg (bingo) fuel present.
TsAGI data estimates 27,5 deg/s if I were to take highest G point (exceeding 9G limit) or 26.6 deg/s if I take 9G limit. Its pretty consistent, as this was not an exaclty 0 SEP turn and possibly aircraft slowed down a little.

http://www.youtube.com/watch?v=n_4WBQDtQ70 at the turn starting at 4:27, Su-27S completes a sustained turn in 14.8 seconds averaging at 24.3 deg/s turn rate. Turn is completed at 4:41 and plane continues manuevers mostly on AB and camera cuts at at 6.28. Lets assume 500kg fuel at landing and 195,7 kg/kN/h SFC (reasonable, as its subsonic and sea level flight). By the time turn is initiated aircraft was carryying roughly 1930 kg fuel, and was weighing 18230 kg. For that weight TsAGI data estimates 25,34 deg/s if 9G limit is exceeded, 24,7 if not.

On both occasions, the difference between observed and theoratical data is 2-3%, IMHO validating it.

Also, If you are claiming Su-27 numbers are not reliable and F-15C is better in reality, its up to you to show F-15 sustaining a 360 turn quicker than those.