AndraxxusAll this does not mean that the Kurds fighting to protect their towns and families in Iraq and Syria from ISIS need be lumped together with the al Nusra.
No, if anything, Kurds can be “lumped” into same category with anti-assad Syrians. Then questions arise; do PYK represent all Kurdish population in the region? How much of the actual population want independent Kurdistan, or just want assad and/or dictatorship gone?
IMHO most Kurds would prefer United States model to dividision; but such decision should only belong to the Kurdish people who live there, not the Salih Muslim (leader of the PYD). Otherwise, we will be seeing a new dictatorship born.
Nope, the field has a stream running through it which means that any caves that they tried to make would be below the water table and would flood.
You are right. There is only 2 meters difference in height. And looking at the google earth myself, seems I was wrong about 3 parts in the video belonged to a single air strike. Buildings etc don’t match the google earth imageary.
Andraxxushow do you know your bombing PKK and not regular kurds. you have some super intelligence and precise execution of target.
Since the start of the events, several hundred sorties conducted with Turkish sources claim (as of 25th September) 1337 terrorists killed. PKK side, or Iraqi’s own Kurdish website only claimed *one* incident regarding TuAF hitting civillian targets, which could not be proven to be true by either TSK or UN investigations.
So appearantly yes, compared to your beloved Russians, Turks do have superior intelligence and *much* precise execution of their targets. As for rest of your comment, its all too nonsense so I won’t bother replying.
Haha, thats nice 😀
AndraxxusIf they were trying to hit the caves in the 2nd strike, they missed again.
Perhaps caves are under that field? So there would be no point in hitting the entrace if you can hit the main cavern. What’s the “bunker buster” version of the FAB series bombs?
Similar attacks made by TuAF againist PKK caves were mostly ineffective with conventional munitions in the past, which forced us to design our own concrete/rock penetrating bombs.
AndraxxusOne last thing: people are pointing fingers at Russia bombing “moderate rebels”, but they barely speak about Turkey bombing the Kurds…
PKK, not Kurds. Its inexcusable to treat entire people as part of a recognized Terrorist group. There is a distinction between Arab, Muslim and Al Qaedah militant. They are not interchangable just as PKK and Kurds are NOT.
As for PKK, they are conducting Terrorist attacks in Turkey, and by all the rights given by the UN, they deserve to be bombed. What’s the Russian excuse for bombing Free Syrian Army or Al Nusra? Have they hurt one single Russian citizen?
I agree with you on the Turkish bombing of the Kurds. There should be more indignation as the Kurds are not only battling ISIS effectively, but do deserve some autonomy.
Marked in bold: Now, is this not “political” horses**t that was supposed to not exist on this forum? As for the rest, Kurd are NOT PKK, or not all PKK members are Kurds. Turkey bombs PKK, a terrorist group recognized worldwide. If you want to ally yourself with bunch of terrorist group to fight other terrorists, this makes you what exactly?
If we are discussing politics together with aviation:
ISIS is a terrorist organisation bombed by US, UK, French, Australians, Dutch, Iraqi and Turkish. (among some others)
PKK is a terrorist organisation bombed by Turkish.
El Nusra, Al Qaeda are terrorist organistions appearently bombed by Russian.
Frankly, this is the perfect sight; All the words able air forces (excluding Chinese and Indian) are one way or another bombing Terrorists in the region.
However what happens if/when all terrorists are eliminated? Will Russian’s allow anti-assad Syrians to rule themselves?
AndraxxusIf you watch the video carefully at around 0:30 mark, there are not 2 but at least 4, maybe 5-6 (or more) bombs hit the ground to the north. Unless target was open crop field, bombing was unimpressive.
Judging by smoke and wind direction, 1st and 2nd parts of the video are likely to be just north of the bombed area in the 3rd part.
AndraxxusIf you ask me, 18,000lbs sounds like a rounded figure and 18,448lbs sounds like an accurate figure.
Its possible, I am not denying it as inaccurate, I merely showed the source I am taking. No point debating over +200 kg of extra fuel anyway
Add internal fuel and you increase the size and weight of the aircraft, increasing drag and reducing performance. As an air superiority fighter, the aim was to remain lethal in air combat, rather than extend range.
Its interesting why this very same logic does not apply when we are talking about internal bay and F-22’s kinematics. Su-27 has 47% more fuel than F-15C. Granted its climb and acceleration is not as good at most parts of flight envelope, but I don’t think anyone would call it less lethal due to its kinematics.
You can say Su-27 is bigger than F-15 (21% by weight 10% by planform area), but F-22 is way bigger than Su-27 (21% by weight 26% by Planform Area) and carries 1 ton less fuel than Su-27.
When considering operational deployment you have the false conception of flying a first day mission deep into a peer adversary’s territory with fuel bags. Never going to happen unless you enjoy heavy losses, the progress will be far slower and shorter in radius that that. Deeper targets will be hit with cruise missiles but the focus from an aircraft PoV will be SEADing back their IADS and knocking planes out of the air. After that, you either have the choice of using that region for IFR, or mounting a ground offensive in that region and capturing airbases.
F-22 has no role in that scenario anyway. You are talking all-around technological and numerical superiority againist your enemy. I don’t like running such scenarios but; on a more equivalent adversary like Russia, A patrol of MiG-31 will easily neutralize cruise missiles (this is its purpose anyway), and Su-27S doing CAPs and MiG-29s doing GAI will neutralize SEAD aircraft.
At the same time, Russian SRBMs and cruise missiles will target your deep targets, and their Su-27/30/35 will try to achieve air superiority. In the end USAF F-22s will find themselves engaging RuAF Su-27/35, no doubt F-22 will have an edge, but it doesn’t help if it has 1/2 to 2/3 combat persistance of Su-27/35.
AndraxxusGuys, here is a snapshot for the UAEs F-16 block 60 carries 4 * gbu-12. I wonder is it possible for the block 60 to carry 6 * gbu 12?
They are mounted on Triple Ejector Racks, so any F-16 can carry 6xGBU-12s. But it was discussed in another thread, appearantly NOT with wing fuel tanks attached on stations 4 and 6. It risks puncturing the fuel tank during the release. I don’t know if its a precaution only (so 6 bombs can be carried together with EFTs if absolutely needed, but not routinely because its risky) or strictly prohibited.
Weight wise, there is no limitation, any F-16 can carry 3xMk-82s in same station together with EFTs.
AndraxxusThat depends. F-15’s nozzles are not the most efficient solution (from drag POV), but F-22’s nozzles aren’t either (from thrust conversion efficiency POV, which increase SFC). As for trim drag, its usage would be in supersonic, not in ferry/cruise speeds.
I was referring to airforce factsheet as most reliable.
http://www.af.mil/AboutUs/FactSheets/Display/tabid/224/Article/104506/f-22-raptor.aspx
As for “in operations” part, i believe situation gets worse for F-22;
-All current F-15C/D can be equipped with CFT. All current F-15E already fly with CFT. Too lazy to look at F-15C’s specs, but F-15E has 10845 kg fuel capacity with CFT.
-3x610gal fuel tanks add 5600kg additional fuel, an can be carried (and if needed dropped) in any operational situation.
For F-22 to have its VLO, it cannot carry EFT. Ferry range is unimportant, but “optimized cruise” is most important factor in combat radius, which is not any different than ferrying. To increase combat radius, IFR may or may not work depending on opposition force. If you equip F-22 with EFT, you are taking away the only decisive advantage of it againist 4+ gen aircraft. This is really problematic if extra range comes with severe survivability cost.
And remember; F-15E with 3xEFT+CFT will have 16448 kg fuel capacity, F-22’s fuel capacity with EFTs is still far less than its predecessor.
This problem is seen and well adressed in another design:
F-35 wing area 42,7 m2 F-16 wing area 27,87 m2 = 53% increase.
F-35 fuel capacity 8390kg F-16 fuel capacity with 2x370gal 5449 = kg = 53% increase.
I would not think such similar increase is a coincidence, F-35 is designed to carry the fuel to match/exceed range of F-16 with its wing fuel tanks;
Plus: F-35 fuel capacity 8390kg F-16 fuel capacity with 3xEFT 6370 kg = 31% increase.
Now, for A-G mission, if you consider extra drag from 3xEFT, external payload, lantirn pods, extra drag from having stores in 3,7 combined with EFTs in 4,6, and with such added weight increasing induced drag on small wings of F-16, F-35 may even match F-16’s loaded range only with its internal fuel, and maintain stealthy in the process.
You can’t say similar things about F-22. And in my subjective opinion, lack of internal fuel capacity is only Achilles’ heel of F-22.
AndraxxusYes. Now question is do YOU?
If you are questioning my credantials, I am mechanical engineer, I have Turbomachinary design as working area, and I have a (not yet incomplete) thesis half involves Advanced Aerodynamics. In my posts, what I wrote is mostly high school physics, and usage single lift/drag formula. I doesn’t require an engineering degree to understand it (or at least I was hoping as such).
If you are questioning my interpretions, I necessarily make assumptions (how in gods name I am supposed to know L/D curvature of F-22 anyway) so they are subjective. In any case, I try my best to leave a room for interpretions other than mine so people who DO understand them can disagree with me.
If you are questioning understanbility of my methods, I don’t explain 90% of WHYs, or I simply skip the steps which are irrelevant to make comparisons, and just give the conclusions unless someone asks. I do so to keep my already boring and long post more readable.
For example If I were to make my “ferry” comparison in the long version:
An aircraft requires lift to maintain any kind of flight, and generates drag; so we have two equations:
Equation 1: (Lift in Newtons) = (weight in kg) * (Aircraft G) * g = 0,5 * (air density at ferry altitude) * (required Cl) * (Wing Area in m^2) * (ferry speed)^2
If you divide both sides by Wing area, you will get an equation lets call it 1A: (wing loading kg/m^2) (Aircraft G) * g = 0,5 * (air density at ferry altitude) * (required Cl) * (ferry speed)^2
Equation 2: (Drag in Newtons) = 0,5 * (air density at ferry altitude) * (Cd at required Cl) * (Wing Area) * (ferry speed)^2
Now lets divide eqn 2 by eqn 1A;
(Drag in Newtons) = 0,5 * (air density at ferry altitude) * (reqiured Cd) * (Wing Area) * (ferry speed)^2
(wing loading kg/m^2) * (Aircraft G) * G = 0,5 * (air density at ferry altitude) * (required Cl) * (ferry speed)^2
As you can see constant “0,5” and variables “air density” and “ferry speed” cancel each other, and Cl/Cd is the aircraft Lift to Drag ratio at ferry AOA.
Equation 3: Drag = (Wingloading) * (Aircraft G load) * (Gravitational acceleration) * (Lift-Drag Ratio)^-1 * Wing Area
Now I strongly stress that this equation is *irrelevant* of aircraft type, and what aircraft is doing. (L/D) is a variable changes with AOA (or aircraft design, if we are talking about different aircraft) , and G load changes with requested maneuverability. Since we are talking about “ferry” G load is “1G”, so I am excluding it from this point on.
As aircraft is at constant airspeed (its not accelerating or decelerating), Thrust=Drag.
Now we can talk about 2nd part; fuel consumption:
(Ferry Range in km) = (ferry speed in km/h) * (Fuel quantity in kg) / (Specific fuel consumption in kg/kN-h) * 1000 / Thrust.
Now instead of “Thrust” I wrote the right hand side of “Drag” equation (#3), and eliminated all the constants, to determine what Ferry range is proportional to.
(Ferry Range of F-22) ~ (ferry speed of F-22) * (F-22’s internal fuel quantity) * (ferry L/D of F-22) / (SFC of F-22) / (Wingloading of F-22) / (Wing Area of F-22)
(Ferry range of F-15) ~ (ferry speed of F-15) * (F-15’s internal fuel quantity) * (ferry L/D of F-15) / (SFC of F-15) / (Wingloading of F-15) / (Wing Area of F-15)
Fill these and you will get exact, 100.00% accurate data for comparing them. Note in real life, ferry speed, wing loading SFC L/D are variable so they are in differential form. However with available graphs they can be best represented by “d/dx” and iterated by computer.
In all the simplicity, I make following assumptions:
1- I assume ferry speed of F-15 and F-22 are the same. This is not a far fetched assumption, as all 2nd/3rd/4th gen I have data have ferry speed around M0,85. Because: As airspeed increase, necessary AOA to maintain level flight drops, so L/D improves, aircraft gets more efficient with speed increase. However after around M0,85 transonic wavedrag starts to add to basic aerodynamic drag and L/D drops sharply. Now F-22 may cruise a tad faster because its aerodynamics are so called “supersonic optimized” but 5,92% wing thickness compared to 3% of F-15 tells me F-22 may possibly cruise a tad SLOWER than F-15. This can easily go both ways, so IMHO “same” is a good enough assumption.
2- I assumed ferry SFC of F-15 and F-22 are same. They may or may not. F-22 is newer, designed with better level understanding of fluid dynamics and can be more efficient, but S-ducts and square nozzles are big sources to generate inefficiency. This can also go both ways.
3- I assumed F-15 and F-22 have same wing loading. Note that it doesnt: From full to empty, F-15E’s wingloading change from 364 to 254. F-22’s change from 358 to 252. This assumption slightly favours F-22 by 1%.
4- Now I assumed L/D of F-22 and F-15 are same when in level flight. This is the most questionable assumption made by mere guessing. F-15 has much thinner wing airfoil, has no VLO considerations like internal bay, parallelism or flat surfaces, but F-22 has negative stability and is much newer in design.
So (Ferry range ratio between F-22 and F-15) = (speed)*(8200/6380)*(L-D)/(SFC)/(Wingloading)/(78,04/56,5)
So this would assume F-22 will have 93% range of F-22. If you like to; you can use Aircraft weights instead of (Wingloading * Wing area). I’ve used Wing Area because thats what I’ve used in my previous post. Reasoning: On similar airfoils, similar wingloading translates to similar L/D.
Getting back to assumptions, if people thinks F-22’s L/D ratio is better, then F-22 would need 7,4% better cruise L/D ratio only to match F-15’s internal fuel range.
@Robbiesmurf: Now instead of posting this wall of text, I write two sentences without going into such details to say the same thing. Was it not better?
AndraxxusI agree its not happening at 20k feet. He probably mis-spoke. Don’t think air shows are really relevant. But point again was that the (F-15) pilot put the F-22 on a pedestal when it comes to BFM.
I don’t see why people think airshows are NOT relevant. It happens anywhere from 0 to M1.0, at sea level, it readily demonstrates the S/L (read = best) kinematics of the aircraft.
But again, even with ‘we more than held our own’ comments, that admiration for the F-22 still filters through. I find it hard to believe that its, as you suggest, entirely unfounded.
Well, F-22 is the best air superiority fighter currently flying. I don’t see why it should not be admired. Possibly, they were suprised that their Typhoon bested the maneuverability of F-22.
“What the aircraft can do, it’s incredible. The Typhoon just doesn’t do that.”
Typhoon cannot even do X-31 doing what’s the point? Since when TVC has a single effect on “turn rates” or “excess power”? As the name implies “post-stall maneuverability” means aircraft is stalled. Available lift (and maneuverability) is smaller than Clmax (equals to best turn rate).
If wingloading divided by lift coefficient is lower, an aircraft will turn tighter. TVC won’t change that.
The greatest flaw of the F-22 is that we ended production too early with too few aircraft built. Its other weaknesses (lack of helmet mounted sight for example) can largely be corrected. It would be great if it had some more internal fuel to work with but it still beats the F-15C in that regard.
I don’t think it beats:
Wing area = 56m2 to 78 m2 = 39% increase.
Airfoil = 64A203 to 64Ax05.92 = Thicker airfoil corresponds to higher drag coefficient.
Thrust = 108kN to 156 kN = 44% increase.
Yet fuel increase is from 6385 kg to 8200 kg, only 28% improvement. So F-15C will exceed F-22 in both flight range, and full AB combat persistance.
BTW; I do believe F-35 may have better overall RCS than F-22.
-Its newer, Its RCS material is better and seen as F-22 upgrade.
-Its physically much smaller, around 67% if we take mass, 55% if we take wing area.
-DSI is known to have RCS improvements compared to splitter plate.
So these should automatically translate to better frontal and side RCS.
Rear RCS?
there is mentioned “round” exhaust. F-35’s fuselage is not circular, only nozzle is. If we talk about the fuselage, F-22’s rear fueselage is equally curved, and it has stinger between engines whereas F-35’s rear fuselage is much cleaner. On wings and elevators, F-22 has 3 parallel surfaces visible at the rear (that follow Leading Edge, Trailing Edge, and there is cropped wingtips), F-35 has only 1 (only Trailing Edge); thats a big improvement translates to less spike zones than F-22. Again I want to mention F-35 is much smaller than F-22. Nozzle may or maynot be problematic. It does have RCS threatments, and since there is only 1 nozzle, even if it has twice RCS return of F-22’s, overall RCS won’t be bigger than F-22s.
This is all wild speculation, but I don’t think we should dismiss the possiblity of F-35 having better *overall* RCS than F-22.
AndraxxusThats possibly the landing image of this take-off:
[ATTACH=CONFIG]240772[/ATTACH]
6xR-27 4xR-73 (R-27s on stations #1 and 2 were visible in the video I took this image, which I can’t find right now)
As a math guy, I did some calculations about Su-33 and MiG-29K’s take off performance in the past (after it was discussed in Chinese Navy thread), I didn’t post it because it was quuite off-topic, I can make a new thread if anyones interested.
AndraxxusYou’re equating drag with wing area. Only applies to a clean jet while any aircraft entering BFM will be combat configured with missiles.
True. I am talking purely about WVR kinematics. 2 AIM-9s or 2 R-73s will not suddenly change the equation. They are even ignored for smaller MiG-29 (graphs say “clean or 2xR-60” give same data to both cases) or F-16 (its already included in basic aircraft drag). Mere 2 AAMs for heavy aircraft like Su-27 or F-15 won’t throw all equations off.
And yet, F-15 drivers hold the F-22 in certain degree of awe even in a WVR fight Col Fornof’s Red Flag briefing comes to mind – (The F-15 has an instantaneous [turn rate] of 21 [degrees] and a sustained [turn rate] of about 15-20 degrees. The Raptor can sustain 28 degrees.).
Just please don’t quote me that clown. He starts BSing the second he opens his mouth, just to thrash talk Su-30MK. He should really stick with military stuff and leave science to engineers. You know, 28 degree turn @ 20000 feet (sustained or not) is physically impossible as F-22 flying to Mars and back, even at its empty weight.
I don’t want to make the same calculation I’ve already made in this forum before, but just to tell about its absurdity; A clean F-16 with 25% fuel can sustain 11,8 deg/s at 20k feet. Same F-16 sustains 21,5 deg/s at S/L. Now IF F-22 sustains 28 deg/s at 20k feet, it could easily sustain 50+ deg/s at S/L. F-16 can really sustain 21-22 deg/s for 360 degree turns in airshows. 10 years in active service, countless demo flights and F-22 didn’t even sustained 20.
Either the F-22’s performance well exceeds what is publicly known or its airframe design delivers better efficiency than legacy models.
Same applies to the Su-27. Against the F-15, it’ll come down to how-high-how-fast. But to suggest that it’ll exceed the F-22 almost across the spectrum, goes against everything that operational pilots are saying about it.
How about thinking about the possibility of no single military pilot has free-will to openly talk about such things? Let me talk about pilot quotes;
Typhoon pilots say, Su-30MKI demonstated better maneuverability than their aircraft. Typhoon pilots say F-22 is at disadvantage after the merge.
So Su-30MKI>Typhoon>F-22 according to Typhoon pilots.
Our idiot colonel claims F-22 > Su-30MKI > F-15C directly contradicting to what Typhoon pilots are saying.
And please, DO question the pilot’s credilibity in such claims;
F-16 pilots say MiG-29 is less maneuverable than his aircraft. Flight manual comparisons say for 70% of the envelope, it is not true.
F-16 pilots always say they have the greatest STR of all aircraft. With 50% fuel it is true for blk30, but with equalised fuel, #1 was Su-27S and #2 was F-15A back in 1990s.
USAF pilots always thrash talked Su-27 about being heavy, unable to sustain turns, and unable to maneuver when heavy; all points severely disproven by flight manual data and airshows. Now we know Su-27 matches exceeds both F-15 and F-16’s maneuverability in all equivalent scenarios.
So they were capable of providing misinformation all along. Why should they be trusted *without question* regarding F-22? To be honest, other than the word of bunch of proven liars, there is nothing at all to support claims about F-22’s kinematics being so superior.
-USAF’s declassified “key performance parameters” have a “demonstrated sustained G” data, which exactly same as what F-15C demonstrates with 8 missiles, obviously inferior to F-15C’s performance with less missiles for WVR.
-No numerical/feature-wise comparison I’ve made supports (or can be bended/interpreted to at least have the possibility of supporting) the F-22’s supremacy.
-BEST demonstrated turn rates in any demo flight of F-22 made in 10+ years is very much inferior to Su-27 routinely demonstrates in more than half of its demos, and pretty much on par with F-15C demos (Not talking about TVC of course)
BTW, regarding our colonels claims. How on earth Su-30MKI is supposed to have 23 deg/s STR? Su-27S sustain 21,75 deg/s maximum at 50% fuel. Su-30MKI gains 2,1 tons in empty weight, its twin seat so there is extra drag from canopy and enlarged vertical stabilizers, and it has exact same thrust as Su-27S. MKI does have canards, but how on earth canards will overcome 10% increased weight (at 50% fuel), increased drag and even incease STR by 6%? I don’t buy that too.
AndraxxusThe F-22 avionics rely on (obsolete) custom processors and interconnects. The software is written in ADA and tailored to its custom hardware (which is making upgrades extremely difficult).
Problematic in terms of upgradability? True, but from performance POV, there is nothing wrong with custom processors, even if they are “”obsolete””. In fact, custom processors designed for a task will have several times performance benefits. If I were to compare general purpose processing unit with customized processing unit by an analogy: Most current Six core Intel i7 will achive 130 GFLOPS of processing power. AMD HD3850X2, a 7 year old GPU, will have 1056 GFLOPS of processing power. It will even achieve 211 GFLOPS with double precision. So for graphics tasks, an “obsolote” but “custom” design can have nearly 10 times performance benefits with same accuracy, or twice performance with twice accuracy, at half the cost and comperable power usage when compared with the most recent generalised design. Most current GPUs have 8000+ GFLOPS of processing power, which 60-folds most current general CPU.
And looking at these numbers, how often would you need to upgrade the custom designed processor even if it is considered several years old?
I was referring to Su-27 with the first part. The F-22 has a higher TWR compared to all variants of the Su-27 incl. the Su-35S (assuming the same fuel fraction).
…..
But across a broader span of flight regimes, I don’t see it keeping up with the F-22 with its lower effective wing loading (body-lift) and TVC.
If you fuel them with same ratio as their wing areas (so that we can count in the drag of their physical differences in size, and make them fueled for same range);
F-22A has 1,26 T/W (5500kg fuel)
Su-27 has 1,21 T/W (4400kg fuel) (4% worse)
Su-35 has 1,32 T/W (4400kg fuel) (4,7% better, assuming 17500kg empty weight)
F-15E has 1,43 T/W (4000 kg fuel) (13,5% better)
For Su-27/35 I wouldn’t say anything conclusive just by looking at their T/W. But T/W difference between F-22 and F-15E is really HUGE.
Now wing loadings, (I wont talk about Su-35 further as I am only guessing its empty weight. With same fuels mentioned above wingloadings are;
F-22A has 323 kg/m2
Su-27 has 334 kg/m2 (3,4% higher)
F-15E has 324 kg/m2 (0,3% higher)
Thrust/Wing Area ratio: (to get ratios of (Thrust/Drag) between respecive aircraft, (T1/A1)/(T2/A2)*(Cd1/Cd2) will give exact accurate result. I take drag coefficent Cd as equal among aircraft)
Su-27 has 0,8% lower T/D than F-22.
F-15E has 14% higher T/D than F-22.
F-22 vs Su-27, featurewise comparsion:
Su-27 advantages:
-F-22 has VLO shaping and has to accomodate an internal bay, both of which necessarily involve some aerodynamic compromises, wheras Su-27 designers have only aerodynamics to optimize.
-Su-27 has a lifting body design and F-22 doesn’t (in that entire fusealage is made from airfoil sections, I am not talking about making a wide box-like body and expect some lift gain from it)
-Su-27 has LERX compared to F-22’s significantly smaller and less effective chines.
-Su-27 has variable inlets, F-22 has fixed (no matter how optimized a fixed inlet could be, a variable inlet will operate at close-to-peak efficiency at larger portion of the envelope, particularly when supersonic)
Equal:
-Both aircraft have negative stability.
-Both aircraft have LE flaps.
A side note:
-F-22’s TVC, has alleged usefullnes of supersonic trimming, but Su-27SK manual shows at above 10000m;
A Clean Su-27: from M1,25 to M1,9 Elevator deflection is less than 1 degrees negative (ie positive stable),
A Su-27 with 6xR-27s and 4xR-73s: From M1,15 to M1,3 Elevator deflection varies between 0-0,5 deg negative (positive stable) and from M1,3 to M1,7 is relaxed stable with 0,5 positive deflection at most.
So we are ignoring the maybe up to 15-20% performance degradation from fixed inlets, maybe 4-5% drag increase from VLO fuselage, and much more aerodynamic design of lifting body, but talking about less than half a degree of elevator deflection at high supersonic speeds, to talk about TVC; which unfortunately is the only “claimed” feature-vise advantage of F-22 above Su-27S.
Wings:
-F-22’s airfoil is at 5,92% slighly thicker than ~5,6% thickness of Su-27’s.
My opinion; when equally fueled, clean (or very lightly armed)
-Su-27 will have ITR advantage over F-22 throughout the envelope. It has too many lift oriented features (primarily lifting body) to make up for its mere 3,4% worse wing loading.
-Su-27 will have STR advantage over F-22 most of the envelope. Only 0,8% worse in Thrust/Wing area similar wing profiles, but Su-27 has more provisions to improve thrust and reduce drag. That said, Su-27 has too much wavedrag, and its stability is too positive at very high altitudes, so in a small region of the envelope, when flying very high (30k+ feet) at low supersonic (M1,0 to M1,2) I would expect F-22 to have mentionable advanage. Even at that altitude, Su-27 should match and slowly exceed F-22’s sustained turn performance as Mach number goes up.
-F-22 will have climb/acceleration (energy gain) advantage at subsonic and transonic, but Su-27 will start to shine supersonic when variable inlets, lower bypass ratio engines, and slightly thinner wings sum up to make significant differences.
F-22 vs F-15E featurewise comparison:
F-15 advantages:
-F-22 has VLO shaping and has to accomodate an internal bay, both of which necessarily involve some aerodynamic compromises, wheras F-15 designers had only aerodynamics to optimize.
-F-15E has variable inlets, F-22 has not.
Equal:
-Both aircraft have wide bodies to generate body lift, but neither are lifting bodies.
F-22 advantages:
-F-22 has chines F-15 has nothing comperable.
-F-22 has LE flaps, F-15E has not.
-F-22 is negative stable but F-15E is not.
-F-22 can use TVC for supersonic trimming, where F-15E’s elevators will generate extra drag (F-15 doesn’t have phimax state; it can use all the available G and not hindered by elevators, but there is drag penalty)
Wings:
-F-22’s airfoil is at 5,92% chord thickness which is much thicker than F-15’s 3% chord thickness.
IMHO when equally fuelled and lightly armed;
-F-22 will have significant ITR advantage throughout the envelope; Same Wing loading, but nearly twice airfoil thickness, and F-22 has numerous features (neg stable, LE flaps, Chines) to improve Clmax. No comparison here.
-F-15 and F-22 will have comperable STR; a 14% advantage of F-15 in T/D is good, but F-22 has LE flaps and neg stability to be significantly more efficient when maneuvering. Thinner airfoil of F-15 will be more efficent at high speeds where sustainable AOA is very low, but thick airfoil will work better in low speed maneuverability. Possibly; F-15E will be a little better at supersonic speeds, F-22 will be much better when slow but at high altitude. Rest will be a close match.
-F-15E will have significantly better in climb/acceleration (energy gain) performance than F-22. 14% better Thrust/Wing area combined half airfoil thickness (logically much smaller level flight drag coefficient), 13,5% better T/W, variable inlet ramps. No comparison here, and I dare say, its idiotic to even comparing two types “energy gain/regain” ability.
A Side Note: I took roughly 2/3 of the nominal fuel load of Su-27S, with 500kg bingo and used equivalent fuel (for same range) of F-22 and F-15E, which I find to be most realistic scenario for entering WVR combat (on equal basis). Note that from aerodynamic POV, F-22 is much larger aircraft than Su-27 or F-15E. So with any increase in payload weight, kinematic advantage will shift towards F-22; Or just the opposite; as more fuel spent, kinematic advantage will shift towards Su-27/F-15E.
These are my subjective assesment of those types according to relatively few technical specs we know/observed/guessed.
AndraxxusF-22 doesn’t have better T/W than F-15 or Su-27, that is assuming 35000 pound class DO means 35000 pound class as some disagree. As for maneuverability, I had written a thing or two about this in PAK-FA thread, I didn’t go further as it was OT.
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unfortunately, an anectode is hardly an evidence of anything. In mere 3 second google search, I can quote an F-16 pilot, trash talk MiG-29’s dogfight ability, and a MiG-29G pilot who says just the opposite.
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Subjectively, IMHO, F-15 looks more impressive and powerful than F-22; It completes 360 turns better, accelerates better; it even rolls equally good.
https://www.youtube.com/watch?v=Y-4EwvGVYxE
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OK, comparing F-22’s 3,7G achieved sustained turn at 30000 feet at M0,9 to F-15A at 50% fuel flight manual data. F-15A can pull;
4,3Gs when clean,
3,7Gs with 4xAIM-7, 4xAIM-9 and CL tank pylon;
3,5G with 4xAIM-7, 4xAIM-9 and CL EF tank.
3,1G with 4x AIM-7, 4xAIM-9, CFT, Cl tank pylon, and 100% internal fuel.F-16 at DI=50 can pull 3,26Gs at same altitude/speed @26000lbs (roughly equal to 6 AAMs and 50% fuel)
There goes another number vs. number comparison that does not support F-22’s claimed superior kinematics.
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Ok, I’ve gone too much off-topic perhaps I should keep quiet.
I was referring to F-22’s demonstrated maneuverability as quoted in KPP as 3,7G at 30k feet M0,9, which I assumed with 50% fuel (as its the most reasonable assumption)
AndraxxusAt transonic and supersonic regime the only aircraft that can match the F-22 will be the PAK FA, with a slicked off EF being the next best thing.
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But the F-22 will still be better than the baseline Su-27 and far better than all variants of the F-15.
Based on what exactly?
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