AndraxxusForty+ years ago people were talking about more or less the exact same threat, only then it was the Mig-25 with its improved speed, sensors, and huge fast missiles. I am not saying that the PAK FA isn’t an improvement over the Mig-25, only that this is one more notch in the steady improvement we have seen for decades, not a revolutionary new type of threat.
Going high or fast was never something revolutionary. However it does work. Many times MiG-25 was attacked by Israeli F-4s, same generation fighters of its era, and it proved very difficult, almost impossible to shot down. MiG-25RBs simly flew on top of F-4s, in a sense “punching through” (by dodging) everything they throw at them. Only after Israeli got F-15s, MiG-25s start to go down. Even F-15s were not always succesful in intercepts, there are occasions MiG-25 dodged all 4 BVR missiles fired by each F-15 and ran away. In desert storm, first air to air kill was a MiG-25 shooting down an F-18, which was 20 years newer and quite possibly better maintained and better piloted. All of this tells me going high/fast and having big, long range missiles actually works, and works very well.
IMHO a well maintained and piloted MiG-25/31 is still a big threat to all 4/4+ gen fighters, simply because a) they have means to shoot their targets at longer ranges b) their targets have no effective means to shooting them down (AIM-120 historically didnt work so well)
If we follow Shaw’s simple formula, then a missile that has lost speed so it is only able of pulling 20g,
can at best engage a fighter doing max 4g at 30.000 ft.
“Hit succesfully with high Pk” should be more correct. There are many other things to consider. First and most obvious is, a missile does not need to hit its target to be effectively kill it. AIM-54 with 61 kg HE warhead needs only to get within ~25 meters of an aircraft to kill it. An AIM-92 with 3 kg warhead, for example, reqiures direct impact to detonate. Even with higher G capability, its doubtful a Stinger will be a more effective than Phoneix to a highly maneuverable aircraft.
If OTOH a fighter can pull 8g at 30.000 ft, then the missile has to be capable of at least 40g.
For starters, no BVR missile can do that, but they can plink down a fighter doing 4g,
a cutting edge WVR missile can take down an 8g fighter at 30.000 ft at point blank range.
It was never disclosed at what altitude an amraam could pull 30g, but i’m betting it was at low alt., since it looks twice as good on paper.
Actually most 4th gen can pull 9Gs at 30k, however at what energy cost? Its -2400 fps for an F-16 with 6 AIM-120s. How long can it sustain such G levels? Probably less than 2 seconds. So pilot would be trading altitude to maintain airspeed, hence high G ability. By the time pilot has dodged a BVR missile, he would have lost 15k altitude and some airspeed, his situational awareness, jetissoned his fuel tanks and mission payload (if any), and enemy still has target lock and able to fire the second missile. With afterburners lit enemy is in an even superior energetic position, closed in so his missiles are more effective. If the victim dodges the second, he would be in such energy state he wont be able to pull high Gs or escape. Thats why I find it ridicolous to dismiss any BVR missile, especially the longer ranged AIM-54 or R-33 and similar types.
Can a single R-37 shoot down a Eurofighter? Possibly no. Can 4 R-37 missiles shoot down a Eurofighter? Possibly yes. Same goes for any missile/aircraft.
AndraxxusAndraxxus sir
for sure we know that they are flying the T-50 performance limited,they said 5 or 6G…How is that turn rate if we compare it with the legacy Su27/Mig29 or F-22/F35?What is the performance target the plane is designed when new gen are available as per your opinion?
thnx
Well, there are no factual data, but as long as you ask for an opinion;
-From the various inspections of Tonkatsu298’s video (which is very helpful due to high engine smoke), I estimated hardest bank angle during horizontal turns are 81 degrees, leading to 6,4Gs. IDK if pilot exceeded the alleged 5G limit, or the limit is higher, ie 6,5Gs.
-T-50 completes 360 turns in 17-18 seconds and that is already comperable to what Su-35S or F-22 doing in airshows. Its -currently- inferior to Su-27 and MiG-29’s technical specifications, and its unknown whether Su-35 or F-22 is doing their best or they are going easy on airframe. We can make very rough estimates about the true performance of T-50, but with available data these would be invalid. Pilot also repeatedly reduces throttle during turns in order not to speed up, which is a good sign; ie whatever G/AOA limit is, T-50 has positive excess power at full throttle.
–http://www.youtube.com/watch?v=LoFmbLm-oKg starting at around 3,55 mark, T-50 makes a near vertical climb while accelerating. Acceleration is quick and noticable, I have never seen any aircraft with such power. It was a revelation to me, because I always thought T-50 would be underpowered with its current engines. Now I believe it will exceed any legacy type in climb and acceleration performance, and if F-22 is not holding itself back during airshows, it will easily exceed F-22 as well; even with 117 engines.
-When compared to Su-35, current state of FCS is neither sharp nor stable, and sometimes even overcorrecting. This is somewhat alleviated by pilot going easy during transitions (example he starts and ends rolls slowly/smoothly, waits for aircraft to stabilize before pulling a turn etc. Another example is: http://www.youtube.com/watch?v=b7kP7_vViSk at 9,19 pilot pulls hard to initaite post stall, then he waits for 2-3 seconds before initating spin, which is unnecesarry from aerodynamic or structural pow.) Still, judging from the usage of control surfaces FCS certainly evolved since MAKS-2011.
Those being said, what T-50 doing today, only 3 years after first flight, is more than impressive. And a shame for LM for their inability to present a single F-35 demonstration.
AndraxxusI do not have a crystal ball with regards to the future of sensor development vis-a-vis detection ranges of VLO crafts, nor can i quantify the effective changes that the stealth designs (designed with growth in mind) will go through in RCS, Low observability, EW capability etc. Is this missile designed to be able to target VLO fighters at those ranges 10,20,30 years from now?
If you are talking about a missile with a usual ARH SARH homing, it depends on requirements. Theoratically, any competent manufacturer can design such missile right now, with nowadays technology. However such missile would be too big and too heavy, and its practicality would be debatable.
However for a ground based EW radar or awacs, size and weigh is not an issue, and they would fail at their job if they cannot simply detect an aircraft at those ranges. Sooner or later, requirements will demand such improvements.
When that time comes, all SAMs would possibly evolve(or devolve) into a command guidance, as it will be very difficult for seeker head on any missile to track a VLO target (at any range), which would be the only targets in the air. Likely scenario (to me at least) is Air to air missiles, will follow. With possibly relying on more powerful ground radars (or launching platform relying on them via datalink), missile will be guided to the target via datalink, and will activate its IR seeker or ARH on its terminal phase. This is already what AIM-120 is doing, by mid course updates for the first 50 km. Why is it so impossible, or laughable to think the same can be done for 300 km? If its impossible to hit a VLO target at 300 km, its also impossible to hit it at 30 km, because terminal seeker is active in the last ~10 km of the flight. Rest depends on the sensor/datalink capabilites of launching platform.
Surely you cannot target these crafts at those distances either in the short or the medium term, otherwise the developers of VLO crafts (who have a much vast access to future technology in sensors and stealth) would not have bothered to make stealth compromise in the first place.
From another POV, developers of ground based radars are required to detect targets at such distances. What good is the early warning radar, if it can only detect a fighter at 50 km? What you are not seeing is, a radar manufacturer can always make a bigger ground or awacs based radar without any problems. An aircraft manufacturer just cant put enough RAM to an aircraft to compensate.
As for stealth “compromise”, only compromise I am seeing is F-35, F-22 and PAK-FA has virtually no disadvantages to types they are replacing (F-15 and Su-27). How better they could have been if stealth was not requirement is a question, but they are better nonetheless.
Do sukhoi believe that the PAKFA could be targetted at those ranges, 10 years from now given sensor advances?
Considering 3 year old T-50 prototypes with interim engines, already shown (in MAKS-2013) 21+ deg/s sustained turn rates, along with great climb performances, and the fact design bears a great lift area for instantenious turn rates I would say yes.
AndraxxusSure, try targetting the F-35 or F-22 from 200-300 km’s out 🙂
No offense but, unlike your other comments, this is utterly childish. F-35 (or any other 5th gen fighter) is expected to be in service for 50 years. Do you really think a Radar/IRST/ESM with such performance will never exist in that period? IMHO in 10 years where VLO fighters see widespread use, there will be a demand for such systems and they will be developed in no time.
AndraxxusSound logic. Out of interest – how much different? [I could go digging – but you might know it straight away]
Like Trident explained, very different. As far as numbers concerned;
[ATTACH=CONFIG]218490[/ATTACH]
Su-27 when maneuvering (ie, LE flaps automatically deflected but TE flaps not) has CLmax of 1.85 @ 24 deg AOA, roughly compares to automatic slotted config at 4th from the bottom.
When Su-27 deploys its flaperons on landing configuration, ~50% of its wing act like 3rd from bottom, Clmax = 2.18.
When Su-33 deploys its 2 stage flaps, ~75% of its wing acts like the last one in the chart, with Clmax = 3.36, though in practice being two stage should increase Clmax a little more, Even judging by this chart, there is 55% increase in lift at 25% greater percentage of wing span. More than that, by deflecting ailerons downwards, remaining 25% would act like 3rd from bottom, (clmax 2.18), It also has 12% greater wing area than land based variants. Plus, lift center is likely to move rearwards due to slats, and *may* require trimming by canards, which would positively contribute to lift.
This excludes the fact that landings are done at ~10 deg AOA, which would mean its reasonable to think Su-33 would have more than 200% lift of the Su-30 at landing or take off.
http://www.flankers-site.co.uk/su-33.htm On this site there are some close ups of the flap and folding system. Su-33 quite possibly has the most complex high lift device configuration of all fighter aircraft.
AndraxxusI believe reason is Su-33 has different, more powerful flap configuration than MKI, and this requires some kind of balancing force from canards.
AndraxxusOne of the well known deficits of the F-16 is its AoA limitation of ~ 25deg.
25 deg is more than enough. Su-27, which may seem like a good high AOA performer is also soft limited to 24 deg AOA.
Andraxxusmkellytx, excellent post, however one thing I have to disagree;
The canard will produce negative lift subsonic to overcome the nose up moment and with an unstable A/C a conventional tail will produce positive lift effectively reducing drag by the smaller size of the tail needed to produce the same effect if the A/C were stable. This reflects a design choice made by the US since generally our A/C have longer range so we put the tails in back. The Europeans want better take-off and ITR and take the range hit. The free lunch thing again.
Canards alone cannot be described as producing lift, but they actually control the airflow above the main wings. For example when they are deflected downwards, they force a low pressure airflow above the wing, and AOA and size of the canards ensure a vortex remain attached to the main wing. While they produce a slight downforce, overall configuration actually increases the amount of lift produced, Which is why we see a MKI on take off has its canards deflected downwards.
As for WHY eurofighter has better STR at supersonic speeds, is the position of canards. Close coupled canards cannot really contribute to lift at supersonic speeds, because velocity of airflow is high but vorticity is low due to low AOA, so vortex intensity grows beyond the aircraft, without any use. On Eurofighter, vortex produced by canards grows on top of main wings (simply because it has distance to do so), creating a low pressure area, efficiently increasing lift without increasing AOA (high AOA = higher drag most of the time). As AOA change is minimal, so does elevator deflection to control unstable aircraft, further decreasing the drag. However at higher AOA, this canard config almost become useless, so Eurofighter also has additional vortex generators on its body, right above the main wing leading edge.
Also two other things I want to point out;
#1 canards do not actually stabilize aircraft, all canard/deltas have also elevators too. However, with every AOA change, canards also move to improve/control airflow above wings, which may look like its the canards doing the job. (Though in practice every control surface, even rudders and ailerons contribute to AOA control in modern aircraft).
#2 This “stabilizing” motion we are seeing on unstable aircraft is not draggy at all, even at slow speeds. Basically elevators move to upward deflection to increase AOA just like any aircraft, but then they move to negative deflection to maintain this AOA (or move to zero deflection if aircraft is neutrally stable). Unless pilot demands AOA change, there is no stabilizing motion after this point at all, aircraft will produce lift for turn without any control surfaces moving a bit, just like positive stable aircraft. Grippen for example sustaining a turn at certain AOA will not see its canards moving, just deflected in a certain angle. What we are seeing in formation flights and landings is due to pilot continously moving the controls, so the aircraft reacts to it.
AndraxxusThere is no question Su-35 is heavier than Su-27S, but the question is how much? Difference between F-16 blk30 and blk 50+ is 530 kg and between blk30 and 60 is 1410 kg including CFTs. Baseline Su-27 weigh 16380kg and roughly has similar equipment to blk30 F-16. Even if the weight increase is ~1410 kg it makes 17790 kg for Su-35 (16910 if weight increase is 530 kg). Considering the amount of lift Su-35 can produce, its a negligable difference in Wing loading, but there is a nice increase in T/W: 1.18 for Su-27, 1,28 for Su-35. (clean 4700kg fuel). Unlike F-16, Su-35 also recieved some weight reductions; Engines, Radar, fly-by-wire, nav computer, are all lighter. Airframe is redesigned and airbrake removed, so its possibly lighter. My estimate is Su-35’s empty weight is somewhere between 17 to 17,4 tons, however thats only an estimate, I have no sources to back it up.
Andraxxusvs. comparisons are fine with me, but as MKI is in a different weigh class, direct comparison without giving a specific scenario is not possible. For example, MKI has much superior range, and can carry some heavy payload and equipment that would never fit onto JF-17. In short, there are some missions an entire squadron of JF-17 cannot do, but a lone MKI can.
It is like comparing F-111 to B-1B or a Su-24 to Tu-22M.
AndraxxusDue to fixed inlets, chances of F-22 having even equal T/W to PAK-FA at M2.0+ is laughable to none.
Even this graph explains it well enough. More than that, all current variable inlets have a ramp at the subsonic section which recovers even more pressure, sometimes even above P0, and went the extra pressure/mass flow via bypass doors.
AndraxxusI find the thought of T-50 being limited to M2.0 more terrifiying than it going above M2.5. Why? Because, T-50 would surely have superior L/D to Su-27/35 (as CFD has much advanced in 30 years) and much better thrust. As far as airfoil is concerned (which entire T-50’s body is), if its drag limited to M2.0, imagine how much Lift it could produce. It would directly translate to maneuverability, or instantenious turn rates. Or how minimal AOA (read: drag) it would need in sustained turns. M2.0+ performance has little or no use anyway, but having 40+ deg/s available turn rate would be just terrifying.
Andraxxus@Tu22m; Does the CL vs airspeed data in the graph accurataly represents the AIM-120s wing airfoil? Do you also have Cx vs airspeed graph for different AOAs? If yes, that can be used to calculate missile’s rate of energy loss, and in doing so, available G at different ranges, producing a lot more accurate results.
AndraxxusI’m confused
different missions, different scenario. On my post, assume a target 688nm away which can be hit by Mk-84s via bombsight. Jackster’s mission assumes a target much farther away that can only be reached with addition of CFT, needs LGBs and due to this, lantirn pods, and different environment that requires ECM pods. Now I re-ask the question: can F-35 match the range of F-16 with 370 gals and CFTs? If there is any *precise* info about a specific mission for F-35, it would be welcomed as we have data to configure F-16 for same mission.
true. and Its not just that. pods are also used to seek and find targets as well, even when LGBs are not carried. just like an aircraft only armed with heat seeking AAMs doe not “need” radar to shoot down an enemy plane. well it doesn’t “need” radar to fire the missiles of course, but it will use it to acquire the target and intercept it. It is even more pronounced with NGs EODAS system which finds and highlight targets automatically, LANTIRNs are not that advanced.
“seeking and finding targets” is a wide area: you can just do it with bombsight, or lantirn, or even pods may not be enough. However last part is important, and I ask to OooShiny; does LANTIRN even capable of reprogramming/illuminating JDAM munitions? Because our F-16s required sniper pods just to do that.
however, I disagree on the heat seeking AAM example; most JDAMs are used to hit static ground targets with minimal collateral damage. If target is a, for example, a building or a bunker, there is no reason to reprogram missile. without laser asistance, there is no practical possibility for hitting a moving target via GPS guidance. And like OooShiny stated, there are also Laser guidance on some JDAMs. Question is how many are produced? 600 bombs is the number in total USAF inventory, quite possibly total number in the world.
Andraxxus@jackster;
F-16 would not need 6000lbs to return home, after all payload is spent and aircraft is actually lighter and less draggy, it would need far less. However lets calculate for that data;
drag index for LANTIRN = 32+19+3 = 54
drag index for Non-jettisonable fueltank pylon = 2×8 = 16
drag index for spent bomb pylons = 2×15 = 30
I assume AIM-9s are on 16s210s drag index = 0
drag index for CFT = 0
drag index for basic aircraft config = 7
drag index for ALQ-131 pod = 18
Total drag = 125
Aircraft weight = 21200 (basic aircraft) + 6000 fuel + 48 (chaff+flare) + 287 (M61 ammo) + 2×281 (weapon pylon) + 42+429+553 (lantirn) + 2×304 njett + 535 (ecm) = 30264 lbs.
Acceleration from M0,8 to M1,25 at 30k feet takes 184 seconds.
Sustained turn rate at M0,8 at 15k feet is 10,27 deg/s
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