Andraxxus“Low speed” is relative; If you are talking about supermaneuverability than yes, F-15 lacks in that area. However other than safety and controllability, TVC has zero contribution to actual turn performance.
What I consider “low speed” is below M1.0; ie which should involve 99,9% of the dogfighting maneuverability. This -irrelevant of design choices- is also the maximum maneuverability of the aircraft. Anything from P-51 to MiG-31 will achieve its highest sustained turn rates below transonic and F-22 Typhoon etc is no exception. With supersonic speeds both lift capability of the wing degrade and drag increase. There is no way around that.
So when people claim F-22 Typhoon etc will have better “high speed” maneuverability than F-15/Su-27. This will prove correct in only two scenarios:
a) F-22 has better turn performance even at subsonic speeds, and it remains better than F-15/Su-27 at supersonic. This I find unlikely, given how unimpressive it is at airshows, and some basic numbers like T/W Wing loading etc doesn’t just add up.
-or-
b) F-22 has less degredation in lift or thrust, or less increase in drag, compared to Su-27 or F-15.
Maybe, maybe not, like I’ve said in my previous posts about this subject, I don’t have anything to prove/disprove anything, but if you list F-22’s aerodynamic features one by one and compare it with Su-27/F-15, it really doesn’t have anything to explain the super-duper maneuverability claims.
AndraxxusMost points are BS and well answered by MSphere so I will not waste my time on them but;
2. The F-22 is not the aircraft avionics world number one. F-35, Typhoon and Rafale have even better technology on F-22’s systems
That’s not exactly news. The architecture of Raptor’s systems is two and half decades old
Better technology, yes, but better specifications? For example comparing two Russian radars -to avoid blind chestpounding-, Zhuk-AE and Zaslon-M: Zaslon-M excels in all parameters, despite its more than 30 years older. In the same analogy, APG-77 is physically much larger than RBE2 or CAPTOR to make up for its any technological “deficiency”.
3. The F-22 is not the most maneuverable aircraft world. Su-27/30/35, Rafale, F-15C, F-16C/E, Typhoon even J-10/11 are the maneuverability aircraft F-22 higher
BS, IMHO.. The F-15 or J-10 don’t even come close.. I believe that Raptor excels in hi-speed maneuverability over pretty much anything, at low speeds it’s debatable.
F-22 will surely have better maneuverability than F-16/J-10/Rafale/Typhoon especially with fuel for long range flights and at high altitude for air superiority missions. Still for same mission, I expect Su-27 and F-15 to offer better overall maneuverability though.
AndraxxusTomcat is correct. CG has to be just forward the main wheels (within a few cm) or the jet will not be able to rotate for takeoff.
not *few* cm. Observe the landing AOA. CG has to stay ballpark around this angle with respect to MLG. Othervise a hard landing will cause aircraft rotate and crash upon its forward wheel, or hit the tail.
The contention about the J-20’s ability to do post stall hinges on whether the canards can generate enough pitch authority to prevent departure at high AoA and how much drag is induced from those maneuvers, correct?
It may help, it depends on the details of the design. In theory its neither necessary, nor its a definitive solution. Simply allowing canards to stall before the main wing is more than sufficent to prevent departures in a canard delta.
As for why it may NOT help. In very high AOAs, a canard may not provide sufficent moment arm by using lift. For example If aircraft’s AOA is 80 degrees, and canards still maintain 10 deg AOA to not stall and generate their lift, there will be 70 degree difference between the canard’s lift vector and the aircraft’s flight vector. Due to this, only cos70=34% of the lift force will provide pitch control. Forces rest parallel to aircraft’s axis will be ignored.
According to my subjective mk1 eyeball inspection. Lift+control canard as employed in J-20 is very different from Grippen, Rafele or Su-30 etc. Those types still retain their elevators and they are relaxed stable; When performing a hard turn, canard is mostly there to improve the lift of the main wing, and elevators (that mean TE flaps on main wing of Rafele and Grippen) are responsible for AOA control.
On J-20, Canards are there primarily for pitch control; they work same as “elevators” positioned in front of CG. This, in essence, makes a J-20 a stable design; An increase in Canard lift will be automatically balanced by an increase in main wing lift, no single autocorrection by FCS necessary. Benefit of such configuration is same as relaxed stable but conventional design: Both “elevator” and main wing contribute to lift, not fight each other to reduce lift & increase drag.
Main problem with such configuration was always the same; interaction between vortices generated by canard, and main wing. IMHO, Chinese guys didn’t attempt to solve this through advanced aerodynamics, but simply moved them as far from each other as possible; J-20 have some dihedral at their canards, and have main wings with dihedral. Canards are way too in front, and lerx is there to generate a dominant vortex to main wing, which should nullify any interaction from the canards.
In all simplicity, this will provide comperable efficiency as F-22 (J-20 has lerx instead of chines, and both wing + elevator contribute to lift), but I don’t expect any vortex control from canards as in Rafele etc. Why? to simplify:
On relaxed stable config of Rafale/Su-30SM; Any AOA increase from canard will increase lift, and increase AOA (destabilize aircraft). FCS stabilizes aircraft by controlling elevators, which also rotate to increase the lift but decrease AOA. Result = aircraft AOA is maintained controllable and lift is increased. Most importantly, in such config, FCS is free to change Canards AOA to control vortex of main wing, which will also increase the wing’s lift. Three control surfaces work in harmony to improve L/D: If overall L/D will be better served by decreasing L/D of canard+elevator, but improving L/D of main wing severely by changing vortices, FCS is allowed to do that. Viceversa, FCS can do that too.
With J-20’s config, canards are most likely not independent from aircraft’s AOA control. Even if ailerons and flaps of J-20 double as elevators, both main lift vector and elevators would be located at the same side of CG. Any increase in lift of the canards would need to be destructively cancelled by elevators, reducing lift and increasing drag.
AndraxxusI think discussion is too focused on “supercruising” alone. Let me mention another engine; Khatchaturov R-35-300 engine of late MiG-23M.
Mass production of R-35-300 predates AL-31F by 4 years. Compared to AL-31F, it’s length is same, has significantly smaller outer diameter (908mm vs 1280mm, even RD-33 has 1080mm diameter), and has slightly smaller inlet (846 mm vs 905mm), but was slightly heavier by 195 kg.
Now, this old engine produces 84kN dry thrust (12% more than AL-31F, very comperable to 117S), and 127,5 kN wet thrust (more than AL-31F), uninstalled. Plus, its a turbojet, and combined with a variable inlet, its thrust increase with increased airspeed. For example, its Thrust vs Mach graph for 11000m altitude shows it could produce around 4000 kg thrust at M0,8 but 14000 kg thrust at M2.4; something definately impossible to achive with 117S, -quite possibly- not even achievable by F119 turbofan.
Imagine Su-27 had R-35 instead of AL-31F. That aircraft could have easily supercruised much faster than Su-35S (86kN from 117S turbofan, vs 84kN from R-35 turbojet). With 37 cm smaller diameter it could not only fit in Su-27’s engine bays easily, it would have allowed smaller engine pods, making the aircraft more aerodynamic. With 14000kg thrust at 2.4, it would easily propel Su-27 to M2,8+ dash speeds. So why did the Russians didn’t engine their Su-27S/P with “old” R-35?
Obvious answer is fuel efficiency (at dry thrust). AL-31F has 68,5 kg/kN-h SFC whereas R-35 has 94,2 kg/kN-h SFC, 37% improvement. So AL-31F design trades kinematics for much better range.
My point? Making engine powerful is hardly a problem. Take the 1981’s R-35 design. its Turbine inlet temperature is 1117deg Celcius. Build it with today’s high strength + high temperature materials -which allow 1900+ degrees celcius-, and heat-up the gas to match TIT limits of new materials. You will easily have a more powerful engine than F119. It will also be lighter, and much smaller. Would it be an ideal engine for J-20?
What is the SFC they achieved with WS-10? How much they can improve thrust on an engine with exact same dimensions, without increasing SFC? Or how much chinese are willing to trade fuel efficiency for a more powerful engine?
AL-31F’s was operational in early 1980s. Izd.30’s will be operational in early 2020s, at best. I can believe Russian understanding of turbomachinary advanced in 40 years to achive a leap in performance. I would say, “with their improved understanding, they have done patching original AL-31, but they cannot go further without fundemental changes, so a clean sheet design will unleash all their potential advancements.”. Such way of thinking doesn’t include their tremendous experience which spans nearly 70 years, and involves countless succesful jet engines, some of which were best in their class.
WS-10 got operational in 2010. WS-15 will be operational in ~2016 Chinese guys say, 2020 I would say. How much do chinese could have learned in 6-10 years to simply outclass Russian US engines? WS-10A was the limits of their abilities in 2010. How many succesful jet engines did they design? Only 1. That is, from solely technical/engineering point of view, a mere re-inventing of wheel. Other than being first succesful Chinese engine, WS-10 is really an uninteresting engine (again talking only from technical POV), which doesn’t really add anything to age old AL-31 design.
So really, adding a 15-20% improvement to thrust of WS-10, keeping same SFC, and making it completely reliable in the process will truly be a great achievement for WS-15 design. 35% improvement, plus similar SFC, improved MTBO, improved reliablity in new design made just 5-10 years later? Its a wishful thinking, almost insulting to the designers of WS-10A.
AndraxxusBe it AL-31F, CFM-56, or other engine. How does that grant the ability (in terms of skill, knowledge and experience) to design a 175kN engine when none of the PW, GE, Saturn or Salyut engineers can’t?
An analogy: Today; you don’t even need to be engineer to disect an 1980’s VW engine, and build a replica. With very basic engineering knowledge; one can easily build a more powerful and more reliable version. You would only need to have a team that knows die casting, and program/operate CNC lathe, miling and boring machines. Perhaps, a heat treating furnace may also be needed. Now, can such misfit team design an engine 10-15% better than today’s VW TSI engines? Most definately not.
I don’t doubt they will built WS-15. But it wont be a 175-180 kN engine and it won’t enter production in 2016. Both are BS from Chinese. Realisically, I believe it will be a ~150 kN engine, enter mass production later than 2019, and maybe more powerful versions enter service in next decade. Thats my subjective opinion, I have nothing to back my ideas.
AndraxxusI have a post I can reference whenever the history of the WS-10 is discussed).
So as I :eagerness:
Excellent description of WS-10’s history, but I want to add another thing to my skepticism. If I were to oversimplify, goal of WS-10A was to provide domestic version to AL-31F. Don’t think I am trash talking their work/achievement as “copying” or “stealing”, but AL-31 was surely available to be disected and reverse engineered. Surely they followed their own R&D path, but when all else failed and they couldn’t solve a problem, they had AL-31F as “how-to” guide, an example. This is more common practice than people think.
However, with WS-15, Chinese are now sailing into unknown waters. Any input from AL-31F design is useless to them. 30%+ more thrust combined with better fuel efficiency and nearly doubled MTBO is a difficult task even for Saturn, despite they did design AL-41F in the past.
AndraxxusMay I ask where are these figures for the J-20 from ???
Good old wikipedia 😀 I was avoiding drawing conclusions because I don’t have anything more reliable. Unfortunately those numbers are likely to be guestimates of others, quite possibly more journalists involved than engineers.
Disagree; supercruise = f(lift, drag, power). For wing loading, the J-20 is perfectly competitive, at least according to your figures, but at the same time we have to know what the level of drag is with the J-20’s engines. The aspect ratio suggests that the J-20 is designed for low drag, and I think the VT sims can give you an estimate of coefficient of drag, how does that compare to other aircraft?
Wrong, Lower wing loading will not grant you higher speed. In fact, smaller wing area is very much preferred for high speed flights. Reason: Cl behaves linearly but Cd exponentially. at 2-4 degrees AOA you will have negligable increase from Cd0, if you can cruise at 4 deg AOA on smaller wings instead of 4 deg AOA on larger wings, its a benefit in terms of drag.
Supercruise (or any dash speed) is a mere function of dynamic thrust vs drag. Like I’ve said drag is directly proportional to wing area, a 26% improvement on Cd curve (which is plain impossible IMHO) will barely bring J-20 to Su-27S’s total drag. That said, with engines that provide higher dynamic thrust at required speed, J-20 can easily supercruise.
Another aspect is that 5th gens with internal carriages have significantly less drag when loaded than 4th gens with external stores. The F-35, for instance, is reputed to be less maneuverable than the F-16 without stores but more maneuverable with stores due to internal carriage.
Debatable. If you are talking about 4x AAMs, most definately no. Basic aircraft drag index of F-16 already includes 2x AIM-9s. Adding DI=12 will no affect at all. If you are talking about 2xAAMs + 2x2000lb bombs, still no, F-16 is more affected due to weight than drag. Add to that 2x 370Gals to match F-35’s range, than there is no comparison, F-35 will shine.
If you arm an F-15 or Su-27 with 4-6 AAMs, there is next to zero performance degredation.
Clean Su-35, which has somewhat more powerful engines than the J-20 while having less wing area, is capable of supercruise,
less wing area reduces drag. You don’t need wings when supersonic, I can make some calculations from manuals if you like. Or just look at MiG-25/31.
as is the Typhoon and perhaps the Rafale.
They have sufficent thrust for that, possibly purpose built for supercruising. J-20 doesn’t.
EJ-200, 89 kN wet, 60 kN dry. 67%.
AL-31F, 123 kN wet, 75 kN dry. 61%.
Heres another excel sheet to show comparison between deltas:
[ATTACH=CONFIG]240341[/ATTACH]
For J-20 to supercruise at same airspeed as Typhoon, it needs to have 22% less drag coefficient. IMHO, unachivable without severely compromising maneuverability.
and newer aircraft tend to be optimized for progressively faster flight regimes,
Due to variable geometry wings, when high and fast, a MiG-23MLD has higher specific excess power than F-15A.
[ATTACH=CONFIG]240340[/ATTACH]
A MiG-23MLD with 2 R-23 missiles is comperable to clean MiG-29 at supersonic, 10km altitude. Againist AL-31F engined J-20, my money is definately on MiG-23.
but at the same time I’ve shown you vids of the J-20 moving at 22.5 deg/sec for 360 degree turn
TBH, I looked at the vidoes but I didn’t catch that, can you provide exact time in video?
The base model MiG-23, however, is shown to be capable of completing a 360 degree turn in 24 seconds, as opposed to 16 with the J-20. The MiG-23MLD is much improved, however, so I don’t know how well it would perform in comparison.
Not 24; MLD needs 21,55 seconds if it sustains its max STR. Problem with MiG-23 is G limitation.
By the way, is JSR on a lot of people’s ignore lists? Wikipedia claims the empty weight of the F-15E is 14.5k, and the empty weight of the F-18E/F is 14.5k as well.
No, but he is ignored. Simply because he behaves like a smartass and he is too arrogant and ignorant to be reasoned with.
I took my data from flight manuals for F-15E and F-18E, which he dismiss as obsolete. In his world western aircraft get heavier as they age, and Russian aircraft got lighter and lighter 😀 However as I have no Su-35 T-50 J-20 manual those are from wiki. F-22 and F-35 are from USAF factbook IIRC.
Why he hates me is another story: When I am commenting about Su-35 or MiG-35 etc, I use Su-27 and MiG-29A flight manuals, use weight conversion formulae inside MiG-29 aerodynamic manual to count-in the extra weight, and linearly interpolate for extra thrust. In a sense, I treat Su-35S as a Su-27SK with 1500-2000kg extra weight, and 15% more thrust. As the end result is not always favourable to his “russia strong!!!” chestpounding, he desperately tries to dismiss every calculation I make.
Well, we do know *something* about the WS-15. As early as 2004 there have been some academic papers on an engine core designated YWH-30 meant for a engine with TW ratio of 10 and a maximum theoretical dry and wet thrust of 110 kN and 175 kN. The papers specify that the design has a 6 stage HPC with an overall pressure ratio of 6.045, and inlet temperatures between 1850 to 1900K. It’s been suggested that the design itself may have been developed as early as 2000. Around the same time studies and papers on a “second generation” single crystal super alloy called DD6 also emerged. DD6 was meant to be used for turbine blades in a next generation engine, and, supposedly (though I can’t corroborate this), had similar performance to the super alloys used for the F119’s turbine blades. Like the YWH-30, the DD6 was said to have been developed around 2000.
Ok, but can you put a number to make a comparison? WS-10A was said to produce 132 kN in their prototypes, goal was 130 kN. Some say its thrust is between 110-125kN. Now we are talking about WS-15; prototype delivered 160kN, you say theoratical thrust is 175, and wiki says target goal is 180 kN? If they were ballpark similar (+/-5kN) I would take them, but I don’t feel objective about putting any of those numbers into calculation. Given we are talking subjective, let me speak my mind.
I don’t want to trash talk Chinese engineers but, only working engine they built WS-10A is only a match to 35 year old AL-31F. And it took 20+ years of R&D to make it work. Due to reliability, unrepsonsive throttle or other concerns we may not know, it still couldn’t fully replace AL-31F. Now, somehow, in their second attempt, they will make an engine that will far outclass PW F119 and -yet unbuilt- Russian engine for T-50?
I am sceptical to anything that is unsupported by hard evidence. I will accept when its built, or there are strong signs about it, but not now. To be frank, I don’t have faith about Chinese making 175kN engine. In my opinion a reliable 150kN engine at WS-15’s projected 2016 production date is still a miracle and a great achievement for Chinese.
AndraxxusDSI doesn’t necessarily mean the aircraft can’t supercruise, for instance, there are claims that the F-35A can supercruise around Mach 1.3 under certain weight conditions that are combat impractical. The point of DSI is that it’s non-adjustable, DSI can be optimized for a specific Mach number, above and below which performance begins to suffer, but that Mach number can be supersonic.
True, but there are practical limits. If you make a fixed inlet work at M2.0, it will have so small throat area (to control shockwaves) that aircraft will barely take off, and possibly not even break M1.0 anyway. Make inlet too large, then there is drag. Fortunately today, engines are sufficently powerful that even with an inlet optimized for ~M1.3, they will propel the aircraft up to around M2.0.
However, if we area talking about purpose-built “high speed” aircraft, then no, DSI is not up to the task.
The reason I assume that the aircraft is built for speed is because of the high aspect ratio of the aircraft; the ratio of wingspan to length is higher than in many other aircraft, and the sweep of the wings is higher than in the PAK-FA and the F-22, not to say the F-35.
Aspect ratio is indicator of nothing. F-35 has higher aspect ratio than MiG-25. Its clearly not faster than MiG-25, its not even “fast”.
achieve supercruise (….) while being hobbled by inferior engines.
J-20 won’t supercruise with AL-31Fs. 25%+ Wing Area than Su-27S which it shares it engines, not to mention VLO considerations and bulkier body to accomodate internal bay. Su-27 can’t supercruise any better than F-15C, same will definately apply for J-20.
About the wing loading, as mentioned before, the J-20 has less internal volume than the PAK-FA, and even high estimates of the J-20’s 100% fuel weight is around 34,000 kg. Assuming 78 m^2 wing area, that comes down to 425 kg/m^2, which is still superior to the F-35; if the weight is lower and it’s closer to the F-22 (length * wingspan is roughly the same as the F-22), it can have around 375 kg/m^2. In either case, it’s better than the F-35A, which has an incredible 600 kg/m^2 wing loading at 100% fuel.
…………..
My point is that if you rate the F-35 above the J-20 in maneuverability, I want some of what you’re smoking. The F-35 by itself is also considered underpowered, if you consider that its large fuel weight results in T/W significantly below unity, especially in the case of the F-35Cs, which, while having respectable wing loading, have terrible T/W.
You are not making an apples to apples comparison. I was avoiding to make guestimates about J-20 which we even don’t have reliable wikipedia info but;
Fuel consumption (kg/km) = Thrust required (kN) * SFC (function of airspeed+altitude, in kg/kN-h) / airspeed (km/h)
Thrust Required = Drag = 1/2 * air density * Wing Area * Drag Coefficient * Airspeed^2
Now if you make assumption that SFC between engine types are same, that aircraft fly at same conditions (so air density and airspeed is same), Fly sufficently fast (M0,8+ that their Cl requirement will be minimal and Cd will be close to Cd0, but no too fast (
AndraxxusTrue T-50 lacks its definitive engine, but I would be careful calling “not fully powered”
Assuming same Cd and SFC, To reach same range of F-35 with 4000 kg of fuel, an F-22, T-50 and J-20 needs around 7500 kg fuel (ratio of their wing areas)
If T-50 is really 18500 kg as people predict; it will have 1,15 T/W, Compared to 1,16 of F-22 and 1,12 of F-35. So while Izd 30 is not there, current engines already put similar T/W. I don’t think anyone would deny T-50 has much more “maneverability” oriented airframe than F-22 or F-35.
As for J-20, if it has AL-31F, it would have 0,963 T/W if it has 18500 kg weight. Which is bad. With 117S engines, it would be pretty sufficent at 1,11.
Anyone thinking current AL-31F may provide enough maneuverability for 4th gen aircraft, should think again: Su-27S (with 5800kg fuel) and F-15E (with 5300 kg fuel) would have 1,19 and 1,34 Thrust/Weight ratios respectively.
Another thing to consider: If J-20 lacks in avionics set, or if it has shorter lifetime on airframe, it may actually be lighter T-50.
AndraxxusSummary = “J-20 is draggy, and underpowered, so it has to be designed as interceptor”. No, an interceptor cannot be draggy and underpowered.
Maneverability would depend heavily on weight, a 3 ton difference will turn J-20 from a flying brick to a decent dogfighter. Without empty weight, all speculations are baseless. However no matter how light J-20 is, one thing is far more certain: With less thrust, similar/greater drag, and lack of variable inlets, J-20 will have way lower (kinematic) top speed to T-50.
Plus, J-20 has no features to prioritize top speed. Canopy, fixed inlets, big canards, all moving stabilizers and AL-31 engines do not belong to a high speed oriented design.
Since we are speculating, my mk1 eyeball inspection says main wings are located way too at the back, that “canard”s will need to generate substential lift to balance the aircraft. As such, J-20’s aerodynamic layout is more like tandem wing to a canard-delta. This, combined with all moving vertical stabilizers, tells me J-20 is more oriented towards high maneuverability than people think.
Andraxxusso how many years aerodynamic development left based on this display.
Well, it only tells TVC and engines work, thats about it 😀 It doesn’t even tell all high AOA tests is complete. However in past few years, AOA limits relaxed far more quickly than appearant G limit, which hasn’t changed much. My guesstimate is PAK-FA has more bugs with structural solutions than aerodynamic solutions.
If you think the T-50 is slow and draggy then what of the Rafale then?
And T-50 is fat. Speaking of fat:
http://www.meretmarine.com/objets/43362.jpg
slow, fat , draggy , lot of energy lose and not recovered
Well I was ignoring your trolling, but this part really made me amuse; Extremely quick energy recovery was the sole thing in this display that exceeded other TVC displays of other aircraft like Su-35 or F-22. For example; an Su-35 can make the flat spin at ~6:45. It cannot make the recovery at 6:53. Su-35 typically falls 100+ meters after spin. T-50 fell not more than twice the aircrafts length, immediately leveled, then made a near-vertical climb in 2 seconds. In fact, T-50’s vertical climbs are so impressive (like at 2:23) it looks more like MiG-29 than Su-27/30 or F-22 displays. Otherwise, -if I were to forget T-50 is a prototype- maneuvers themselves are not big deal; they can be easily replicated by Su-35 or Su-30SM.
AndraxxusImpressive display by T-50 in MAKS-2015.
https://www.youtube.com/watch?v=BN9t8hs4l_E
not sure if its posted before, I didn’t have time to read all the posts lately.
AndraxxusAnd you believe the figures floating around for the F-35’s RCS (0.001-0.01 sq.m) are vastly overstated?
Well.. perhaps you and Andraxxus are both right and the average RCS is actually north of 0.1 sq.m meaning the aircraft is not really VLO and can be tracked at ranges well exceeding 100 km. In which case they’re probably better of with an upgraded F-15E re-engined with the F119. (The Russians in turn ought to scrap the PAK FA in favour of a Su-35Z.)
Left: A Su-27 with 10 AAMs. Right: Possible RCS reduction potential like Su-35. Lets call it Su-35 for the sake of argument. What is the RCS of Su-35?
At 0 degrees? its 27 sqm
At 30 degrees? its 5sqm.
Minimal? its <1 sqm at ~6 degrees.
Can you take a PR advertisment number to say “Su-35 has 1 sqm RCS with 10 missiles” as fact? No, you made the logical assumption and called an “average RCS in frontal arc”, 9sqm in this case.
Looking at the graph, even in frontal 90 degree arc, on which occassions rcs is actually 9sqm? Su-35 makes a tiny, unnoticable, 10 degree turn from direct head on, and RCS will constantly fluctuate between 27sqm and 0,8sqm.
Excluding any software capability, if your radar is rated to 100 km range vs “8 sqm” target, you wont be able to reliably track Su-35 at this range despite “9 sqm”. At head on, you will lock at 135 km, and due to dynamically moving nature of target, lose track after 1-2 degree rotation, regain-lose-regain until you get to 56 km when your radar will reliably track target (and be able to engage it with SARH missiles).
In practice, radars constantly lose and regain their targets, in fact, TWS mode is relies on it. A small no-return will not break target tracking. Software will simply interpolate it. On F-35, such motion will not give sufficent data to “interpolate”. On same analogy, it would be like trying to track mentioned Su-35, with above radar at 115 km (capable of detecting 14 sqm). Su-35 will fade out at 2-3 degrees, briefly re-appear at 20, 35 and 40 degrees marks. Insufficent to fire a missile at it, but enough to know there is a -relatively- low observable target around and act accordingly.
PS: Note that despite calculated 9sqm RCS, a Su-35 can still have 40+sqm RCS spikes; supporting what MSphere said.
AndraxxusBefore labelling something ‘BS’ perhaps you ought read it first.
I wasn’t calling your comment “BS”.
Just going by Oooshiny’s posts. But the radar equation suggests that a 0.01 sq.m frontal RCS (Eurocanards claim upto 0.1 sq.m clean I believe) would put the detection/track range at least one-third that of a loaded Su-35S (with RCS improvements) at the same aspect. Even more from other angles. One sixth as low against something like the Su-30MKI.
And OooShiny’s post is:
[ATTACH=CONFIG]239830[/ATTACH]
See the radar fron range?
you’re rubbishing an non-existent figure (‘0.00062 sq.m’ is meaningless).
You see what I am rubbishing now? This low “radar front” range is simply wrong.
I see. So ‘400 km vs 3 sq.m’ target is kosher but ‘0.01 sq.m frontal RCS’ is not. Also, since I didn’t state a ‘given range’,
I thought you are quoting OooShiny’s range, and assuming 0,01m2 RCS, which would have been incorrect.
AndraxxusWell, all that boils down to tactics. F-35’s pilot will definately know his advantages, and play accordingly. However, that doesn’t mean Su-35 pilot will not have any of his tricks. Granted, F-35 will track Su-35 well before it, and use this SA to optimize his chances of success in engagement, but Su-35 pilot will also be aware that he is againist an opponent with superior SA, and will use tactics to minimize it. Without doubt, at longer ranges F-35 has advantage, but anything that narrows the engagement distances moves advantage to Su-35, and Su-35 has the means to do it to a degree.
On an infinite theoratical zone, with 4 vs 4, an F-35 pilot can always simply chose not to engage Su-35 if conditions are not favorable, and continue trying to sneak in. So WHEN engagement occurs, we can say F-35 will be at advantage, that Su-35 may be ambushed from side/rear etc etc; Even if no one makes any mistake, possible outcome is Su-35 got killed without even knowing F-35 is around.
However in real life, I don’t see that would be possible. Talking about ranges/distances, lets talk about other real world distances; diagonal length of Netherlands = ~340 km, International airspace above baltic Sea at its widest point = ~270km. If Su-35 are conducting CAP, or challenging air-superiority there, these distances don’t really provide much of a room for F-35 to maneuver and avoid Su-35. Irrelevant of 1vs1 scenario, in a 24 vs 24 in a 300 km box, Su-35 will see and track every F-35 in the air, there is simply no room for moving around sensor coverages. Surely F-35 will have some energy advantage vs Su-35 in most scenarios, but Su-35 also has excellent kinematics to overcome that. I don’t see a crystal clear winner there.
For escort and defense, Su-35’s job is even easier provided no other enemy assets around, because you know enemy VLO aircraft will eventually come to a certain distance from a certain point. Of course, F-35 with long range cruise missiles vs static targets, or escorting a high-flying target like AWACS or tanker would be more problematic.
Still, in the end, would I prefer Su-35 over F-35? Probably not.
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