85th_Maverick

And where have I contradicted myself when I've stated that in one case it's possible to have a greater overall drag of the missile as the CD increases trough a lower speed range and in another case it's possible to have the overall drag still lower (decreasing) as the CD increases through a lower speed range? Maybe I haven't used the right formulation that the resultant drag may be: higher, lower or about equal as the CD increases through a decreasing speed range along it's trajectory, as it all depends on the dynamics of the trajectory, yet still, usually the drag should get somewhat higher. Finally..., you have made a test and what I've just said is confirmed and I honestly appreciate that you took the time for this test! The speed increase function inflection can be seen on the first graph of this recent test that you've provided. As we can see, with a variable CD with speed, the speed variation curve isn't smooth and has a short change in curvature (if this was the easier way of mentioning it). Simply, that change in curvature gets greater as the CD variation is also greater! Btw, we've both forgotten one important thing, have we? Even if the missile is flying at a constant AoA (let's consider it a low constant AoA or close to zero) and the CD is varying with speed, you'll still get a speed versus distance (or time) curve inflection or local change (as we've just clarified), but what happens in DCS as the missile's AoA is not constant throughout the speed decrease...? The following are the 2 big reasons why the CD will drastically increase as the airspeed drops from any value for a 1G holding vehicle: Reason 1: If you test fire a missile straight without any lock on a target in DCS, it will go straight and it will try to maintain a 1G normal load, right? As the speed decreases, we all should know that the AoA will exponentially start to increase in order to maintain 1G! The usual CD versus AoA function's exponent is roughly 2, thus, at a double AoA, we'll usually get a 4 times higher CD. So, as the AoA on our DCS missile gets exponentially higher as the speed decreases to hold 1G and the drag coefficient also gets exponentially higher with AoA, just think or test (much better to test) how rapidly the CD increases as the speed gets lower, no matter the speed decrease ranges for testing. Even an airplane provides this rule very straight. In level flight, if you throttle to idle, or simply shut off your engines, the more rapidly you'll have to increase your AoA as the speed gets lower in order to maintain 1G or a leveled flight, the more rapidly your speed also drops, which confirms that the drag gets higher, but indeed, this is for the condition of trying to provide a lift equal to weight. If the plane/missile would maintain the same AoA as the speed rops, then the gravity force vector will gradually "thrust" that body forward and reduce that speed drop, but that is logically not the case we're talking here about! Reason 2: The shock stall! Now this is one further very important thing, which is zero modeled in DCS for the transonic region. As it is called, during the normal shockwaves development over the low as well as the high pressure areas around a missile, bullet, plane, whatever, the major disruption and airflow detachment (possibly flow reversal to some degree and in some areas) over the lower pressure region leads to a big chunk of the negative pressure coefficient being "eaten" up by the disruption, thus reducing the global lift coefficient to almost half of what it was before the shock stall. Now, think of this regarding our DCS missiles that want to hold 1G as they pass through the transonic region. The CD at any constant AoA gets higher by default because the speed is entering the transonic range (reaching a maximum at some determined speed), the lift now gets lower and it also reaches a minimum value (which is roughly half that which occurs at M = 0.1-0.2) at some speed throughout the transonic region and the AoA needs to compensate and will roughly double in order to keep to necessary lift for 1G for that condition. All in all, the overall drag force should irrefutably get much higher throughout the transonic region for any missile, plane, UFO (if they would exist and aerodynamics would affect them) or whatever wants to keep a 1G load on the normal axis throughout the speed drop. Here are some useful links: https://qph.fs.quoracdn.net/main-qimg-29400b8ac2598d8d72e99982d3089195.webp https://media.springernature.com/original/springer-static/image/art%3A10.1007%2Fs00348-017-2466-z/MediaObjects/348_2017_2466_Fig1_HTML.gif https://slideplayer.com/slide/6326661/21/images/89/Flight+Characteristics.jpg (just look at that CL max curve around the transonic region) DCS doesn't simulate a CD increase nor a pitch down (known as Mach tuck, from which also another drag increase due to the required trim would occur, separately) on aircraft when passing through the transonic region, so it's quite far to talk about the CL variation in there as well. The only plane which I've found so far to simulate a pitch down increasing moment as the speed gets closer to transonic, is the Su-25. No other aircraft simulates it at all, while some aircraft such as the Su-27/33 simulate it the wrong way around as an increasing pitch up moment (can be noticed as the AoA gets higher by itself) as the speed gets closer to transonic. I ddin't want to veer of the subject, but I felt it was necessary to talk about these things too, at least once if they'll ever be fixed! Now, I didn't initially have the proper time to test that AIM-120C on a similar scenario to this one: In this youtube footage, that long "BEEP" is the sound of the trigger being pressed and the missile launched. So, when he said: "Clear to kill...", the pilot squeezed the trigger which caused that long "BEEP" before the operator terminates saying: "...he's a bandit, bandit". That's a bit before 2.0nm away from the target, but this isn't the big thing that helped the missile steer with plenty of "room" (taking into acount both distance and offset angle), but the actual angle which isn't great at all. Here's a picture that I've done just now with the DCS F-16 during the exact moment that the real pilot launched his AIM-120 and in about similar conditions of closure rate, angles, altitude: As I've launched the AIM-120C in DCS, in less than 2 seconds it has already acquired the interception trajectory (meaning that no more steering was necessary) and for the later 2-3 seconds, the target got hit. So it had plenty of room anyway. I've also struggled to conduct the same test using the Su-33 with R-27ER and still managed to hit the target (but the ER was still turning towards the interception angle before hitting it), but in order to have the ER start turning at the right moment (to mimic the way the AIM-120 jumps just like an AIM-9 from the wingtip, which it does) all I've had to do was to launch it at the right moment a bit before the 2nm away in order to have it start steering towards the target at roughly 2nm from the target. So if the ER with it's low simulated lift managed to kill it's target from that condition, what to talk about the AIM-120 which did it as if it's an AIM-9 all the way, lol? Basically, the new Aim-120 has a much greater lift to drag ratio, which is wrong! If it would have indeed a greater lift, then so the drag should also increase, but that would be in contradiction with the fact that the drag is already great on all the missiles we have in DCS. What I conclude is that this great lift increase on the Aim-120 is abnormal/unrealistic! Here's the track: Aim-120 vs R-27ER on turning limit.trk Regards!

Of course that the drag is a product between CD, reference area and dynamic pressure. As the speed drops, if the CD is held constant, the speed will gradually drop with a smooth logarithmic function of 2 (the rate of deceleration decreases and at half-a-speed you'll have 4 times less resultant drag), but if the CD will increase even slightly, say between X2 and X1 speed values, you should have at least a slight noticeable deformation of that function. The higher the CD variation (real CD values are as high as 50% or more in transonic compared to supersonic below Mach 2 (above Mach 2 it rises again due to heat and higher fluid viscosity)), the higher the speed curve fluctuations. Isn't it logical that only for a constant CD you will have a smooth non-fluctuating speed curve? In other words, we can say that varying the CD with Mach you'll get the same result as keeping a constant CD and varying the dynamic pressure's speed's exponent throughout that given Mach range, such as increasing the speed's exponent with the right amount instead of the CD to result a similar drag, the functions would closely overlap, but that's not how it should be, as only the CD should vary through Mach and not the speed's exponent! That's why I repeat, that the way they look from your graphs (except the Harm), both the speed's exponent remains 2 (as it normally should) and the CD remains constant (which it shouldn't), reason why you have that smooth logarithmic curve for speed drop, instead of a slightly more constant speed drop slope or even greater speed drop slope (depends on how much the CD increases) over the higher CD region. And you have the Harm evidence that you have personally shared and we can see how it's speed and drag force (CD times dynamic pressure and ref. area) vary with Mach, even if for a short speed/Mach range, but it is there. If the CD gets higher as the speed decreases, you don't necessarily need to see a greater drag, hence greater deceleration. Although as the CD is about twice greater in transonic than subsonic and about 130-150% greater than supersnoic, it's pretty much possible that a slightly greater deceleration may occur when passing through that highest CD range (I won't say it's for sure, but depending on CD values over Mach range, it's not impossible either). The best way to find out the difference between a constant CD and a variable CD with Mach is to compare two graphs of the same missile, same initial speed, overlap the graphs and see the differences in the speed/Mach versus time. Copy that and thanks for the heads up, but this proves that DCS is kind of behind with these aspects as you can and will always notch every missile for a split second and will also always have it go and stay for chaff if you release it before notching. How much would the chaff (depends on it's quality) affect a missile's tracking ability in different scenarios such as clutter and notching is something hard to tell without plenty of tests I guess.

Thanks for the confirmation about the AIM-7. I haven't tested it. But, even according to this graph there is no visible variation of the negative logarithmic function of deceleration. It's exactly like the previous ones, with no corresponding high deceleration rate variation according to the current speed between 925kts and 595kts or between M1.4 and M0.9. Very good on taking the time to extract data and plot it in Matlab (I also use Mathcad) for the Harm. Perfectly done for the HARM. So ED has worked out some CD variation with Mach for the HARM as your test shows (although the higher drag Mach/speed range should've normally been greater), but at least they've simulated something for the moment. And as I repeat, the first picture of the AIM-7 doesn't prove any similar effects. Please correct me if I'm wrong or I might be missing something, but as long as the deceleration variation is constantly logarithmic with no inflections between some 925 and 595kts, it means that only the dynamic pressure is varying to affect the instantaneous drag, not the CD as well! Copy that, so if you say that they have the right info regarding burn times and specific impulses, all they'll have to do is to finally adjust the resultant max launching range for a conventional condition (ex: both the attacker and target head on at Mach 2 (a Mach 4 closure) at or above 33000ft) by tweaking the aero data alone. Now, sorry but, 473lbs shouldn't be something like 214.5kgs? That's almost 3 times. Yes, as it can be seen the interception point (the little circle) is still above the F-16's flight path, but I don't know how much above. I remember from your initial post as saying something like 20 degrees or so. Could be then. Copy, then only our accumulated knowledge and experience might help estimate those numbers more or less correctly. Yes, I also had that fear in mind for a moment saying that, thinking that the R-27 and/or R77 might get a too low final drag if their real base drag coefs are somewhat higher than that of an amraam, but I considered saying it though, because as a momentary fix they'll still get them closer to real than being as handicapped (mostly due to drag) as they currently. Agree regarding the antenna bar which isn't so supersonically shaped, but, the long central fins are about the least draggy in supersonic. Don't account only on the fact that the reference area is much greater compared to that of an amraam's fins. In supersonic, the friction drag behind/within the mach cone (or simply behind the highest intensity oblique shock) makes the least of all drag, the major drag contributor being the pressures distribution which affect the shape and positions of the shocks. Having much shorter span and thereby a very low aspect ratio, they are ideal for about the best lift to drag ratio in supersonic (in subsonic, these things are exactly upside down, the higher span versus MAC length or aspect ratio gives better lift/drag), so they may overall be a bit more draggy or the same draggy as the amraam's mid fins (higher reference area than for the amraam, but some lower resultant mid fins CD). I didn't take the time to do some quantitative analysis for this matter, but I only call the rules atm. Afaik, a gross ratio between lbs and kgs is 2.205, thus 238lbs = 108kgs and 478lbs = 214.5kgs. Thus the R-27ER has roughly double the amraam's weight. So, in order to have the R-27ER and the aim-120C decelerating in the same fashion (same axial negative G-load, decelerating), with the same inputted minimum CD, the reference area should be double for the ER. As the reference area isn't double, the same CD would have the ER decelerate slower than the amraam for the given weights. The reference area taken is equally important as you also know. It's all about having the right resultant forces simulated. If the conventionally taken reference area is smaller, then the coefficient will have to "compensate" in order to have the same force resulted. Wow, very valuable data, but I wonder what has been tested for those results to arrive. Either they've used a high reference area while testing a scaled model missile (as this is what we're talking about) or have only tried testing some missile body portions with a non-supersonic performant cone which would normally generate a high CL increase due to wave riding and with no fins at all, otherwise I don't get those very low numbers such as 0.132 a peak value. Speaking of witch, the Cl (that you've referred to in your earlier post) is conventionally named "rolling moment coefficient". I've also had some initial confusions with it, but after working with all 6 coefs (CL, CD, CSL, Cm, Cl and Cn) I haven't mixed them up anymore. I'm not correcting you or anything, but for that moment I thought that you were really trying to also talk about rolling moment coefs based on those graphs. Copy that! Thanks! Again, very valuable graphs! Well, here you can see the deceleration function inflection as the missile decelerates through some speed region. Maybe it's only illustrative (not exactly accurate), but you can see on different lines how the speed starts dropping more rapidly below some value (as it seems, below 1000-900 meters/second or M 2.9). It isn't yet a transonic speed (as most logically there is no portion of the missile left with subsonic flow regions) but shows an increase in CD as the speed drops below that range. So sad I don't have the needed money to intend some scaled models testing in a nearby wind tunnel and at least find out some more accurate results even for low subsonic and from there I'll try to extrapolate the results with dedicated maths. The correct 3D geometry is everything, the rest come easier through the required resources. Exactly! max launching distance from attacker to target, not how far the missile can travel in level flight until it can no longer hold 1G against the earth. That's how I also mentioned the max ranges when I've talked about them. Of course, a higher lift for the same drag alone will mean greater Lift/Drag and thus greater range. Reducing the drag besides increasing the lift will, of course get an much higher max range boost. Idk about the lift increasing if it's really a good idea as it already seems to be the most accurate for the Russian missiles, but, idk, it's ED's knowledge and analysis that should do the right thing! Don't take it too seriously then. I was only trying to tell the difference of what people might want/like and what should be real. The fact that I like to abuse and exploit the flawless in game AIM-54's target tracking abilities (identical to the aim-120) to simply score kills one after the other is one thing while in real life these proved effective only in almost perfect conditions with straight flying targets. Indeed, but what about the power output? If it can only see a target that's at maximum 8nm away compared to a plane's radar that can see one from 10 times greater, wouldn't that logically mean that it's reduced radiation power will also cause it to lose the target if far enough? Idk, there's indeed also the possibility that they've configured the aim-120 to go "pitbull" only when 8nm out to get close enough to the target without warning it too early, but then why not make it turn on it's seeker and search for the target from 4 or 3nm if the stealth incoming would be a priority? I personally guess that due to it's very small size emmiter/receiver config it can't correctly see/lock aircraft from further away than 8nm (which was set as a generally optimum turn on lock on range). I'm very pleased talking about these things with guys like you! Regards!

Hi Nighthawk and thanks for your reply! Of course that the drag varies as a squared function of speed which is part of the dynamic pressure! As you just say, the time of decelerating between M1.4 through M0.9 isn't necessarily long, proving that a very high drag occurs just there. If you meant that it passes very quickly between M0.9 through M1.4 when accelerating, that doesn't mean that it won't pass through the highest drag coefficient ranges, it only means that the motor provides enough resultant axial Gs to pass it through that region in just a second or two, but the effect is still there. Now just show me where does any of our in game missiles start decelerating faster between M = 1.4 through M = 0.9, proving that there's a variation of the drag coefficient. We, in aerodynamics prefer to talk mostly in coefs, cause those are the most important. When we want to calculate resultant forces/moments, of course we'll need to account for speed, but until then, the performances (which is what I want to talk about) are affected by coefs alone. Do we agree up to this point? You have the tracks and the Tacview! Show me where does any missile have a different CD with Mach. The pictures that you have presented also prove no CD variation with Mach as well, just like in DCS! Thank God! I really hope they'll try to reduce the supersonic CD and increase the transonic CD to more realistic levels, then finally adjust the required burn times and impulse rates to get the more correct max ranges. I honestly wish them the best! But, I don't want to see a heavy R-27 flying side by side with my A-10 as the aim-120 already wants to prove. Seriously, that aim-120 has about double of the maximum corresponding subsonic lift coef., which is not ok. That very useful youtube footage was cut after the aim-120 was released and according to the closure rate and also confirmed by the youtube counted seconds and distance callouts, the missile was fired from 2nm, but, let's be honest, judging by the footage the shooting aircraft was flying almost towards an interception course with the target so the missile didn't even need much steering so we can't correctly extract it's real max lift coefficient and real critical AoA without data measured within the missile (if this has ever been performed). Until we find the more correct input data, a temporary and more useful solution would be to just use the same minimum drag coef of the amraam to the R-27s and R-77 (although this should have lower supersonic CD, but even identical to the AIM-120 is still better), the corresponding motor impulse versus, burning time, instantaneous weight and reference area will do the rest in simulating how the missiles would decelerate. The inputted base drag is just too high for all of the rest, but at least they simulate a more correct drag vs AoA. Here are some facts: https://en.wikipedia.org/wiki/Grid_fin#Design_characteristics Have they designed those fins to have greater overall drag? No! As you've said, that getting closer and closer to transonic, the drag starts increasing more rapidly with a much higher peak than other missiles prove, which is fairly correct so far. Now, are you saying that it should be more draggy than an aim-120 according to your CFD results? The reality shows different. In supersonic, the things stand upside down for the lattice fins compared to other missiles. The CD gets slightly lower than the lowest in subsonic (in subsonic the friction drag gives the highest amount for these types of fins). It's a more complex explanation of how the grid fins can exploit the effects of the attached shockwaves to reduce the overall drag only through pressure distributions. That way it has a lower than subsonic CD. It's at supersonic speeds where the R-77 excels and only when passing through transonic, either accelerating or decelerating, it's drag is indeed greater than for any other missile. I also use CFD, but i correct the results with mathematical equations and derivatives to extrapolate the more correct values. The CFD is a gamble. Depending on the type of calculus and it's factors, the same model data will give very different and sometimes incredibly erroneous results. It's like you're trying to find the door with a hand on your eyes. Without some experience and right knowledge to find the door, you can't turn part of the hand away from your eyes and completely blind you won't know when you passed through it (got the right results by chance) or passed right by it. You are only contradicting yourself saying that the heavier ER decelerates faster than an amraam. What is the decelerating G-load? Isn't it the ratio of the speed difference (from an interval), divided by the time it took to decelerate through that interval (which is the deceleration), divided by the gravitational acceleration constant? It is! So, dividing that deceleration force by the product of dynamic pressure and reference area..., you guessed it, the CD pops so you can check it out! You'll find out how great the ER's CD is in game compared to other missiles. And yes, it also has a high speed performance shaped cone, and yes, also it's fore fins are designed for a reduced supersonic CD (another story). I don't understand your statement, as the plot you've just showed proves it faster. The truth lies in what you just wrote above, that ED knows that all of the Russian modern A-A missiles (R-73, R-77, R-27) have too much base drag in every condition. Yes, very little! Videos or tracks prove "how much" speeds is bled by the amraam. Ok, I agree with you then as I've also calculated the wing loading on the AIM-9 (using the projected fins area (as you'd do with an airplane)) and compared it to the AIM-120 indeed it was a couple of times higher (which is very much). But again, even with the cone's induced vortices the aim-120 still proves to have a maximum subsonic lift coefficient of about 1.5 or so. That's waaaay too much. A subsonic CL max of 0.7-0.75 for it should be usually correct in accordance with a reference area of 0.05m^2. What wasn't possible with the A model, but possible with the B (they're aerodynamically the same)? Delay to start tracking the target, or some other limitation? Sorry, just curious! No, I ain't ignorant as you believe and NO, through the cone generated vortices (cause that's were that seemingly magic body lift comes from) doesn't create a "huge amount" of lift on the body of the missile at all. I have probably forgot to mention that I was only talking about the subsonic lift for the start. In supersonic yes, the "wave riding" effect generated by the cone is gaining a high percentage of the total lift, but not that great in subsonic. Also, regarding transonic/supersonic, don't forget (if you know about it) a very important aspect that the drag versus AoA functions have a greater increase in transonic and also in supersonic (more rapidly progressing derivatives) and as such, this "lifty" missile will suffer from a much higher CD increase with AoA in transonic/supersonic compared to subsonic. For instance, as the speed starts growing from roughly 1000ft/s TAS (about 1097km/h TAS, 0.9M) towards the maximum speed, then decelerate back towards around 1000ft/s, there is NO corresponding/expected fluctuation in the speed function. It's just a smooth straight line during acceleration and a smooth/constant logarithmic curve during deceleration from supersonic to almost subsonic. If a drag coefficient variation would've taken place, the speed increase function should've had a fluctuating curve while passing through the transonic region and the speed decrease function should've also had a fluctuating curve as the curve should've started to deflect downwards between M1.4 (as you've said) or 1562ft/s and around M1.1 or 1227ft/s where the highest drag coef would be taking place (the CD in transonic is roughly 2 to 2.5 times that at Mach < 0.1) and then continue as almost a straight line towards M0.9 and from there on go logarithmic again towards M = 0. At least that's how things go in reality. That drawn presented data is most probably illustrative and the speed versus time functions are simplified only to show the speed and range advantages, NOT accurately detailing how the speed rate varies with time as that was not the purpose of their analysis. When you come across various data, you should always use your judgement and knowledge to tell if there's anything wrong and in this case, that data is not reliable for our discussion. For those who don't know much about it, yes, it seems magical. Ok, you may be 100% right about it and let's say that, ok, the aim-120 is now the first DCS missile to achieve a more realistic range, but still, what kind of "optimal launch conditions" would the R-27ER need in order to hit a target from 130kms? Again, a Mach 4 closure speed at 12000m proved that the missile starts falling when reaching only 68% of the given range. So, how much of "optimal" is there left? Same goes for the R-77, AIM-9, R-73 and all the rest. Ok, I believe you about the AIM-9 and R-73 AoA limitation during flight, so that's not their actual critical AoA, but a performance holding max AoA, but how people "like" the R-27 and R-77 lift (which I also admit by tests that is about the most accurate) may sometimes have little to do with reality. To give you an example of why "liking" isn't necessarily what it should be, I "like" the AIM-54 being able to have tremendous lift compared to it's wing loading or compared to the R-33 which loses lift much sooner for a similar wing loading (the R-33 seems more realistic anyway), be a very "long legs AIM-120" and be able to maintain lock on targets no matter how far or low below the horizon they are and almost immune to clutter such as the AIM-120, but the reality tells that it was losing a maneuvering target quite easily. I'm grateful to this conversation and looking forward to seeing your opinion again! Cheers!

Hi, After the latest updates the aim-120 has received an unprecedented lifting performance benefit together with an overall lower drag versus AoA, which don't seem right! I've tested that for all of the air to air missiles, the simulated drag coefficient versus Mach function between subsonic, transonic (where the greatest should occur) and supersonic is about constant. It's literally a flat line throughout the Mach ranges. This is a track comparing different BVR A-A missiles: Aim-120 vs R-27ER and R-77 max ranges comparison.trk Tacview-20200110-223205-DCS.rar As you can see, the aim-120C and especially the B model overpass their real counterpart's range performance quite well. The aim-120C has hit a target from 70nm (130km). That's exactly the distance that the R-27ER should have. The aim-120B goes even further than the available real numbers show, hitting it's target from 55nm (+100km). No DCS modern Russian A-A missile reaches it's given max range, actually not even 80%! The following is a grossly accepted (an average between many airfoil sections and 3D body shapes) variation of drag coefficient versus Mach at the minimum drag AoA: https://image.slidesharecdn.com/aerodynamics-partii-150210010059-conversion-gate02/95/aerodynamics-part-ii-71-638.jpg?cb=1423531445 For the aim-120, the drag versus AoA doesn't increase almost at all. There seems to be almost no drag coefficient variation with AoA as there's little difference in drag when the aim-120B/C is flying straight at low or high AoA or turning! All other A-A missiles have a natural drag increase with AoA. Is it right that the aim-120C (with it's small fins) can fly slower than an aim-9M and almost as slow as a combat loaded A-10C? It seems that we don't need an aim-9M anymore in dogfight, we can now use the aim-120 as it turns better. A track regarding the aim-120's exaggerated lift: Aim-120 very high lift.trk For instance, the wing loading on an amraam when it's fuel is burned (for an A-A missile, roughly half of it's weight is that of the propellant) is of more than 1000kg/m^2, while that of an A-10C at MTOW is about 445kg/m^2. How is it possible that now the aim-120 can simply fly almost as slow as an A-10C when both are flying at their critical AoA. Anyone who has a bit of knowledge in aerodynamics can know that a straight and high aspect ratio wing has a much greater maximum lift coefficient than the other way around. That alone should be enough to raise some concerns when seeing this simulation. The wing loading differences makes it an even greater "throw"! Indeed, I cannot know the exact numbers but I should accept using a bit of calculations and logic that when flying at it's critical AoA, an aim-120 cannot hold it's weight (no propellant left) any longer below around 500km/h. Btw, the R-27ER starts falling at 620km/h IAS, which is quite realistic! The aim-120 should have a very low critical AoA lift coefficient (or max lift coef. which is usually around 0.7 for most missiles), a very low useful wing area (about 0.05m^2) and very high weight. During playing around against the aim-120, I saw that it was turning with me at very low altitude and slowly decelerating just some tens of feet behind, on the same turning circle that I was flying on at 9G. At about 900km/h, that missile was turning with me at about the same rate (G-load), while any other missile loses lift more accordingly below 1000 to 1200km/h. Here's a comparison track against Russian A-A missiles: The F-15 player can easily evade any russian A-A missile just by full aft stick and roll.trk The poor R-27s (any model) is the worst of all when it comes to lift. Although it has the biggest fins with the greatest lift coefficient of any missile, it ironically has the worst simulated lifting and max range performances of all. It's not about fairness or stuff like that, but the absurd is now bigger than before! The R-27ER should be able to hit a head on target from 130kms according to the internet. Tested in the above track with better than ideal conditions with both targets at a closure speed of over 4000km/h at 12000m altitude and the R-27ER reaches it's realistic critical AoA of 16-17 degrees and starts falling when traveling just 85-88kms. It only reaches some 68% of the real range. Even the AIM-120B has greater range than the R-27ER...! It's not even worth talking much about the R-77, for which the initial version alone should reach more than 80km. In game, after being fired from 2200km/h at 12km high it falls after some 50kms. The above Tacview is very useful in for a check out. The R-73 has a critical AoA of just 5 degrees? Here's a track: R-73 5 degrees critical AoA.trk The aim-9M also seems to have a critical AoA of 7. Only the aim-120 has it as high as 27 degrees.

They may have, but it still appears in the module manager and you'll still get this error if you try installing it. I've un-installed an re-installed DCS completely to make sure there was no issue of having the game folder moved or stuff like that as the above comments refer to as an issue, and still the error persists if I want to try installing it on the stable version. All I can do is wait before I can get my hands on to test this one inside out.

Hello, There are 2 issues that I've recorded in a track file: 1. Somewhere 500km/h and 700km/h, when using full pitch up input combined with a couple of half-a-second left-right roll inputs followed by releasing the roll but keeping the full up pitch input, a constant pitch oscillation has developed to an amount of about 10+ AoA variation. The effect of the plane's pitching moment of inertia (which is alright as it is) coupled with the FBW's programmed logic which tries to maintain a commanded AoA by anticipating the required elevator deflections and elevator deflection rates can sometimes overlap just enough to produce a pitch resonance/oscillation. This looks like a programmed FBW constants issue which should be relatively quickly solved by slightly reducing the elevator's pitch rate dampening deflections. The same pitch but also yaw oscillations can be found on the DCS F-18C lot 20 at different speeds and altitudes, but there should be another thread opened to deal with it. 2. Much later in the track you can see that at higher altitudes, when the KCAS gets above 600-650, the airspeed and Mach will start to rise when climbing and decrease when descending. From the outside view though, the laws of physics are normal, the speeds seem to vary normally when climbing/descending, but only from the cockpit the things are a upside down. This can be related only to a HUD indication issue. Here's the track: F-16 FBW pitch dampening + high altitude airspeed and Mach cockpit indication versus attitude bu.trk

Thank you for the plenty of answers! Ok, so here's what I've found: -That "local" word next to a server's mission options (the word "local" is very non-intuitive in explaining what this feature actually does) only appears if the server has NOT checked an ENFORCE option from the mission options column, thus trying to say that it permits the client to use his own option set in his gameplay menu. In reality, there's a bug which won't allow the client to use his own option every time even if the "local" word appears for a server's options. I've tested that ONLY if the server has also selected that option for himself from the gameplay menu will that option also be allowed for clients when they see the "local" word next to it, otherwise, if the server has a different option set in his gameplay menu, the client won't benefit from that option even if the "local" still appears. So that "local" will most of the time lie to you when joining a server, unless the server has also chosen that option for himself.

Exactly, though in DCS the F-15 can do about 14 seconds for a 360 (until the velocity vector comes on the initial heading) for the same airshow config (fuel % and smokewinders if installed). Speaking about the F-14, I also waited so much for it to appear, but what I see is that it's actual FM in DCS can make it obtain an outstanding STR and here is why: -Too much landing flaps lift. Your G-load jumps quite much when using the flaps. -Too great critical AoA for both flaps in and flaps out. Even the wing tips don't want to stall at AoAs as high as 40, thus leaving you with no roll departures and complete control about the roll axis when using the rudder. Normally it would depart in spin above 22AoA (slats only extended), no matter what you try with stick and/or rudder. All in all, this combination of too high critical AoA (in-game tests show that the lift still increases above 40 AoA) and crazy flaps lift coefficient can be absurdly exploited by the F-14 players below say 300kias. I love the F-14, but it's aero data needs some revisions!

In fact, you guys should better try this: -Use the outside view (the best would be the chase view) in order to not get confused by the "simulated" blackout. With zero "warmup", just pull to 7.9Gs (do not touch or go over 8 ) and hold it there as constant as you can. Switch between cockpit view (to monitor the blackout "simulation") and outside view (to monitor and constantly hold the 7.9G load) and you'll find out how the "simulated warmup" gradually takes away part of the blackout. So the simulated "warmup" doesn't care whether you release the G's for a while to let the pilot grab a breath and get better straining or not, it simply starts reducing your blackout effect right in the middle of high G's. There will be some amount of blacking but the effect never occurs. As stated before, you can hold 7.9 forever and not blackout and still see enough in order to fight, while at exactly 8 you'll neither blackout nor get slightly rid of it after the warmup effect takes place. 8Gs seem to be simulated as a threshold between coming out of a full black and triggering the loss of consciousness.

Thanks Harlikwin and everyone else, This is a very interesting discussion and I appreciate the level of information shared by you guys to those like myself and others about the level of performance that the new radars are capable of. Knowledge is beautiful;)!

Hmm, sorry but I guess I should take back some of my words though, cause no matter how strong the radar may be, the notching (at least the 1st notch) in clutter environment (hill or buildings behind you) should break the lock because: the doppler radar will see your closure rate as that of the ground and the pulse will be full of clutter, so there should be no way left to keep the target tracked/locked. Out of notching through clutter, yes, the radar has at least one mode of keeping you locked. I don't know about how good a PESA/AESA radar does when it meets a notching target through the clutter, but I guess the PD loses it there.

It's understandable now. I know little about radar capabilities first of all and what I know is a piece of this and that, but nothing complete. So yeah, if the newest radars are automatically switching between pulse and doppler (I now believe that that's what pulse-dopplers actually do) according to target condition (in and out of clutter, with closure rate or with zero closure rate) then, indeed, it's very plausible that no matter what's behind a closing or even notching target (hill, building, santa^), the radar would change to a mode that will try to keep the target locked. At least this is what I believe now based on your explanation. Wow, so they've really evolved these radars quite well then, if nothing can't escape a radar lock even if it physically touches the water from as long as 20 kms away (if that's what you say). Thank you!;)

Hi, I couldn't find any topics about it, so perhaps everyone else understood what it does automatically, while I'm still unable to get it. For example, I have set my "G-effects" simulation to NONE and checked the "use these options for all mission", but after joining a server which has -G-effects: none (local)-, I get the it simulated as ON. The same happens for other options as well. What's the difference between seeing the "(local)" word next to the server's mission options and not seeing it? I couldn't find any explanations so far! What am I doing wrong?

Sorry for starting this thread, but there are different locations on the Caucasus map through which if you happen to fly your plane, it will appear on awacs and ewr radars. Idk if this is a terrain simulation versus radar line of sight issue or an AI issue, but this happens and there's no way you can help it! If, let's suppose you're doing a SEAD mission and you've well planned your route which normally keeps you terrain masked constantly until a certain point, there are places on the route where you'll suddenly get a RWR signal from awacs or ewr which effectively happened to see you through the terrain! If providing a track is needed, I'll do it! Cheers!

Hello, I hope there wasn't another thread regarding this same subject and if so, I'd kindly ask the moderator to link me to that one instead of putting it wrong here! I'd like to address a few questions to those who have some knowledge/experience on real radars performances for the basis of this subject besides a few remarks related to my initial questions about the actual radar performances simulated in our DCS. Q1. Are modern fighter aircraft and awacs radars able to see or even lock (fighters only) other aircraft flying in a dense clutter environment (such as below a mountain, hill, city) from any look down angle, unrestricted? Q2. Are there real surface vessels (ships) radars able to lock targets that fly over water well below 10 meters AGL, for example at 2 meters above the water constantly and from what range can the lock become effective if so? R1. After plenty of hours of testing, it seems that all of our simulated fighters radars (both US and Russian fighters have the same abilities) can track and lock other airplanes which fly in a non-notch condition from a very high look down angle (sometimes even from 80 degrees considering that the locking plane will have to pitch down the nose to keep the target within the gimbal's limits) and from distances from as high as 40-50nm (as for an F-14B, F-15 and F-18) no matter how dense the actual clutter might be (a mountain behind, a city or simply the earth surface). A 40000ft+ fighter (Su-27, F-18, F-14, F-15, etc.) can rapidly track and lock a head to head approaching fighter that hugs the terrain at around 5-8 meters AGL constantly. R2. I can see that there's "a new boat in town", called Type 052B/C which can lock my plane flying as low as 2-3 meters over water (using autopilot) and killing it with HHQ-9 from plenty of kilometers away! If this ship's radar is so capable, why isn't the Ticonderoga or Moskva radars able to do the same as well? I'm not a radar expert, but if the radar beam can scan below the horizon (in the case of ships probably), how would the reflections that bounce back from the water surface (a very low but present reflection) affect the data signals? Just asking, isn't the radar suppose to have great difficulties to lock it in such conditions? Cheers!

Lol, but after the "warmup", you'll be able to hold 8G forever even if the screen is quite dark, still you won't blackout. I'm surprised that nobody ever tested the edges to see! By how I see it, the realistic G effects modelling is somewhere in-between of what we have atm! First, a trained pilot, even without the "warmup" isn't suppose to blackout at 6g in 5 seconds with he's G-suit working properly. This is too much too early to be accurate! There are a lot of video demonstrations in which even with no straining nor scheduled breathing, the subject holds more than 7G for about 10 seconds before he calls it a stop. With the correct straining and breathing procedure, they can withstand even 12G constantly for at least 10 seconds. The other end of the simulated function as I repeat myself, won't let you completely blackout and get G-loc even if you'd keep it forever at no more than 8.0Gs! This is how it's simulated atm! Test it! Have a look at these guys for instance: https://www.youtube.com/watch?v=y9T2HI1eiTA -(this one actually did 12G for 15 long seconds)-

Well, after the latest updates, it's kind of exaggerated in the other way! The pole wires produce too much damage to planes now. Take a flying tank, A-10 or Su-25 (the most resistant examples) and fly through powerlines. You'll insta-explode! 100% damage every time, unless you may sometimes hit the wire with the fin/fins, but with any other plane part that you hit the wire with, will have you exploded! One guy replied here with an example of an EA-6 Prowler which received damage from a powerline, and even though it's not designed to be an armored vehicle with wings, it still landed safely!

You're right, but how about the mission conducted by the US using a good bunch of 8 AH-64s in low level flight formation sent to attack and destroy an Iraqi capable radar station? The reason why they were undetected by the radar they were sent to destroy is either due to flying well below the radar coverage cone (the further away, the lower you are below the detection cone) or due to the fact that the radar simply couldn't identify or even see them.

Sorry for going in so thorough into the subject, but it seems that the AIM-7 for instance does indeed use 2 signals for steering inputs: one from it's own receiving radar, the other as a backup from the launching aircraft's radar. This is from wiki, indeed with little details, but probably just enough to confirm that the missile can start steering towards the target that is for a moment outside it's seeker's FOV: "The missile detects the reflected signal from the target with a high gain antenna in a similar fashion and steers the entire missile toward closure with the target. The missile guidance also samples a portion of the illuminating signal via rearward pointing waveguides. The comparison of these two signals enabled logic circuits to determine the true target reflection signal, even if the target were to eject radar-reflecting chaff" It is indeed talking about chaff discrimination from the real target by having the missile now "tell back" to the launching radar what it sees and the launching radar will tell: "no, that's not the right signal, that's a chaff", but may the same way it can also receive mid-course updates to steer towards the target that it's own radar receiver can't yet have in it's FOV. Idk, just a guess!

Now, about the SARH missiles: "Why does the SARH missile no longer listen to targeting info once the first lock has been lost?" I admit that I've only looked on what wikipedia tells about SARHs in general, but, for example do you have any information about the capability of an AIM-7 or R-27 model which does just that? This way, no matter if the target has gone past the seeker's FOV, it will now receive mid-course commands via datalink or whichever form of data info (indeed, if the whole system is designed to support this also) from the "mother radar" and steer until it's seeker is again within the required FOV to track the reflected signals. Kind regards!

Thanks Tharos! I understand better now. Regards!

Just found it, this is what i was referring to: Kind regards!

Copy that Tharos! I really appreciate your answers! As for the SARH, yeah, I meant it doesn't have an active emmiter as radar, has just a radar receiver receptor such as a signal gathering dish. Kind regards!

Exactly man! You've just re-told what I've already explained from an engineering perspective! The turning radius is only a function of lift coefficient (if wing load (mass and reference area) and fluid density are already constants), while the turn rate is only a function of speed and centripetal acceleration (or G-load as reference). Kind regards!