pierrewind

Confirmed for me. Any value entered in bad/alt/feet is being converted to m and the proper m value is good in relation to the bad left alt.

Hi Razbam. I have been enjoying the mirage 2000 a lot! But flying in formation, I couldn't help but notice the throttle response was odd. After investigation, I found the engine had no modulation between about 75% to 90% throttle. Would it be possible to fix it? Thanks!

Well, in order to not mix up things, we should go back to the facts. -Testing showed an error between the actual UUA vs CL charts. This error could be attributed to a few factors. 1) Our testing or the charts provided are false. 2) UUA is wrong and does not correctly represent the correct expected behaviour. 3) Flight model performance is wrong for a given UUA number. These are my hypotesis. I'm sure we could find more. Now as to were the error lies... Let's start with point 1. 2 of us have tested the mig 21 model with similar results. We could run into similar errors, but if the data capture and the widely available informations are correct, this option is to be ruled out. Point 2... UUA is wrong. Well, my personal limited testing shows that the AOA and UUA numbers are correlated based on a mach number. The error produced is in accordance with NASA papers. As these papers do not specificaly apply to the mig-21 it doesn't really prove anything, but to me it makes the behaviour reasonable. Though not proven 100% accruate. Lastly riojax is of the strong opinion the UUA is wrong. However at this point other than from videos comparing the mig21 to the mig23 UUA behaviour on the ground which is not something comparable. No one has been able to come up with anything but opinions regarding this matter! Point 3... flight model performance. As you might understand this is were my heart falls. If we go back to the airshow video and the UUA at 32 UUA we yeld about 40% extra performance. Even if the UUA was wrong, given the charts available this 40% extra performance would put us right at the stall point. This should for obvious reasons not be safely and continuously manageable. Though it is to note the weights are unknown, the airframe could be modified and some avionic logic could be different. At the moment, I can not match the sim performance to the reality. To me it seems this mismatch is produced by slightly wrong performance tables leading to over-inflated simulated performance. I am very much open to receiving actual and proper information/testing to once and for all close this debate. I would love to be proven wrong!

I am very sorry, I must be too dumb to understand your amazing reasoning. Let's just consider for a second, the UUA was accruate, wouldn't this issue possibly come from a different place? Like airplane overperforming? Or let's just consider the mig 23 and mig 21 are two different airplanes. Oups... there are... :doh: Two different airframes in two different configurations (in your photo, the mig 23 rotation has started; right before it the instrument shows about 5 units... very close in fact to what the mig 21 shows). Plus both are on the ground and subject to factors such as ground attitude even down to struts that could have different pressures but since it is two different airplanes, I'm going way to deep for something irrelevant... I am very sorry, I am unable to see something that seem so obvious to you. :cry: But I would love to learn more from your great knowledge as to why the UUA is wrong.

Riojax, I very much appreciate your constructive statements and your amazing testing skills. However, I disagree with some of your findings. :thumbup: I won't go through everything again as I have done it previously. However, If you look at the Mig-21 airshow demo, you will find the pilot puling 32UUA at 515 km/h giving out 3.2G. If you do the same in DCS you will pull 4.5G. That is just about 40% extra performance. So something is obviously wrong. We can't seem to agree on the exact error. To me, there is a discrepancy in the tables between UUA and CL. But frankly, I don't care if this issue is from a bad UUA coding or inacruate CL. Though, my testing agrees with NASA papers and the AOA/UUA relation is coherent with mach numbers meaning the UUA is behaving as I expect it to. Whatever the source of the problem is, my issue is that there is a problem with the mig 21 still overperforming.:pilotfly:

Guys and girls... How to say it nicely... I didn't want to give out my opinion before I actually went through my testing... :music_whistling: I was biased, I did see the welcome improvements on the departures and so on... Like most I thought this is it, the mig performs as it should. :pilotfly: So I went through the same testing as before, And my disapointement was noticeable when I realised we still are able to pull a lot more than we should without consequences... In fact the CL VS UUA plot is still as wrong as it was before :cry: ... I can consider the charts identical... as you can see attached. So as good as the departure is, we are still able to extract too much performance out of the mig without consequences... (The "safe g" pull should be significantly reduced by more than 40% in most cases...) :music_whistling: I am disapointed by these finidings. I hope it is improved in the future... :book: https://forums.eagle.ru/showpost.php?p=4304015&postcount=61 Ps: Max CL is from previous testing Pps: additional testing shows 4.5G at UUA 32 and 515km/h instead of expected 3.2g... With an airshow weight likely below the one I used...

Thank you hiromachi for this clarification. I did see some tweaks to the flight model. As welcome as these are, I would like to see your team going down to the roots of the problems... For exemple, the engine model... as of now, the engine acts more or less like a fixed pitch propeller. I can very easily tell it lacks proper engine physics. You can tweak the engine as much as you want to make it more belivable, but it will not fix the fundamental issues with the dynamics. The CEII isn't that complex in terms of engine. It is just a very common atmospheric piston coupled to a constant speed propeller. Yet, right now, the simulation is off... I think similar stuff is going on in terms of aerodynamics. So...I will allways encourage the improvements to your models. However, if magnitude is unable to master the physics of a relatively simple engine, What should I expect with an airplane more complex? I wished the CEII was an airplane I could enjoy, but as much as I like it... I just don't. I fly into flaws anytime I touch it. :/ I wish some improvements will be able to make it behave corectly someday. Best of luck to your team! Ps: I'm sorry to hear one of your team members went ballistic! I hope you'll be able to bounce back from it.

Well Magnitude has brought some welcome improvements to the mig21 recently. However looking at the quality of their only module (CEII) and the promisses of fixes for the sound for example running back more than 1 year ago, I have concerns. The CEII was developped as a test bed for the Corsair. But, in terms of flight model and engine model, the CEII is a fail to me. So let's hope for the best, but I have my doubts... Magnitude hasn't achieved much so far. I would not like to see them fail, but so far I don't see them succeding.

Spencer Suderman has compiled the roll rate of many aerobatic airplanes. According to his findings the roll rate of the CEII is right about 164°/s . Many variables are unknown though. At the moment, to me the CEII flight model is quite a way off in many aspects including roll rate. The roll rate has some kind of weird acceleration/deceleration going on, making it very unpredictable. These deep flaws lead to the inacuracy of the the flight model and to the discrepancy with the expected behaviour.

All fine for me! It is likely related to your specific install/config.

Got into the very same issue. Unable to restart after engine shutdown (inverted flight). Fuel not being reintroduced to the engine... I made sure I was in the restart enveloppe and followed the procedure. Problem seems to be only with inverted fuel starvation as I was able to do a simple shutdown/restart.

Same issue here... Not too sure about how it came to be though. Scan azimut to more than 1100 degrees as well...

I'm with you on that one. Promisses are great. But to me, to put things in perspective, In the timeframe it took heatblur to create the Amazing F14 and enhance on the Vigen; Magnitude managed to come up with... a not so well done christen eagle, and not many improvements to their mig-21... I really wish them succes; I am very interested in the F4U and F8, but Let's say for now, my enthusiasm is very much restrained by questionable competence to deliver quality products. I applaud the work that's been done, but to me there's still a long way to go.

Are you sure the autorudder is disabled? On the yak 52 based on my limited testing, the rudder is to be used during all phases of flight. As for the engine modelling and it's performance, I haven't checked the numbers. However, Performance asside (which to me is believable), The behaviour of the Yak 52 engine is correct. Instantaneous MP pressure increase with power, propeller overshoot at speed if the power is increased quickly... We are dealing with a good engine model. The christen eagle well... is a constant speed prop being modelled like a fixed pitch but with some tweaks to mask some of these deficiencies...If you add a quite bad flight model to this what does the Christen eagle bring to the end user? A 3D model? Yeah... I'm not saying the yak is perfect, it is not. But the christen eagle module is to me not even close to the quality offered by the yak52.

While, the yak 52 has its flight model issues (reverse airflow but mostly inverted stall problem), it is in no way comparable to what the Christen Eagle offers. The Yak 52 displays a mostly believable and coherent flight and ground model. It's engine dynamics are on point, and while being a relatively low perfomance airplane, it does what it's supposed to do nicely. I also disagree with you BBRZ, to me, the yaw is quite well modeled. During loops, the yaw corrections for most propeller aircrafts are very minimal. I think the Yak 52 FM is adequately displaying it. To me this is quite the opposite to the Christen Eagle. To me, the Christen eagle displays some significant errors in its engine modeling (the only prop airplane in dcs that is nonsense). The ground handling is Meh and to top it off, the flight model displays some big flaws. Like...The roll behaviour (any pitch correction during a continuous roll feels like a snap but it isn't. there is some weird acceleration/slow roll rate); at low airspeed the engine effects are overpowering the aircraft and the snapp roll/ tumble behaviour is odd at best. To me there aren't many things to enjoy with this christen eagle at the moment. I am part of those who regret buying it. But clearly I don't regret buying the Yak 52!

To Me, there are currently some big flaws to the flight model. 1) Too much perfromance. The Wing has a CL too high between 40% and 80%. This CL is directly responsible for a increased instantaneous turn rate by about the same number...Bad 2) High alpha flight caracteristics. As you get into High AOA, according to the mig flight manual, you should start to get into buffet. 3) It will not stall 4) As per the mig-21 flight manual "If the control stick is not set neutral immediately after onset of stall, during 3-4s, the aircraft will start oscillating briskly and unsteadily about its three axes, with high lateral g loads and rudder forces", "rocking of wing to wing". But since the current mig-21 is not stalling, it's not really relevant... Therefore to me, at the moment the flight model is badly flawed. As for the UUA-1, my personal position is quite different from Riojax. My testing showed -Perfect linearity between AOA and UUA at all speeds -Mach effects showing with a good predictability and in accordance with papers from the NASA. As such, to me, the behaviour of the probe is to be deemed accurate. Now, Riojax seems to be convinced that this probe should not display any errors due to non referenced calculators. However, to my knowledge no such system exists on the mig-21; the probe is only calibrated to show correct LOCAL angle of attack based on ACTUAL LOCAL angle of attack. I see 0 mention of any compensation between measured (actual) LOCAL AOA and actual AOA. Therefore, to me the UUA-1 Probe is behaving as it should. I'd love to hear more from Riojax as to why the UUA-1 probe does not behave correctly, but I need this info to be based on facts and available documentation. PS: Riojax, I think when you're saying the the behaviour of the UUA probe is incorrect. I think you say that based on Max CL coherent, then as you pull to a specific UUA, the CL doesn't stay coherent. You assume this error is due to a faulty UUA behaviour. However, based on my personal testing, I would tend to say the behaviour of the probe is correct. Therefore to me the only variable left is the CL i think the CL coded by magnitude is wrong. Your point of view is that the probe is wrong and the flight model correct. I want to hear more from you as to why this UUA sensor is bad as that could clear up some misconceptions from anyone.

To me there are some significant low speed controlability issues. It makes some of the maneuvers not work as it should. Hamerhead is part of it, but a basic imelman could be a problem. I wished some of these issues where looked into but no com from magnitude... The christen eagle is a great little monster. But to me the FM in DCS is very much sub par. (impossible to fly actual advanced sequences properly... weird behavior when pushed, or during rolls) If you want to go proper hardcore aerobatic, I would suggest Aerofly FS2.

Got to play arround With AOA vs UUA. Based on data obtained, the linearity of the the relation is confirmed. (At 0 UUA, AOA was extrapolated). This shows a correct behaviour in regards to the variation of UUA and AOA. The mach effects shows up with an almost perfect predictability. It seems to be maybe a tad too strong, but it is coherent to the papers shared in this topic. With this data, the behaviour of the UUA probe is to be deemed reasonable. :pilotfly:

Some quick testing on my side. (see attached Sheet). I yeld very similar results to those found by Riojax, which should be considered as a good sign :P . Based on actual Charts, it shows a significant increase in CL anywhere between 40% and 80% Outch... It shows a clear downward slope that shouldn't exist. I kept the data above mach 0.9 for reference. However my flying wasn't precise enough to consider these values as accurate. I was mostly pulling too much as the speed decreased. This would tend to confirm a drop too charp in the current flight model as it should mostly remain constant below mach 1.1-1.2. However At these speeds, we actually get closer to the expected flight performance. Now for the AOA issue. I must say, I'm getting down the rabbit hole at this point. On the attached document this is what is being said for a configuration similar to the one used in the mig 21 (page 11) "The tests were conducted over a Mach number rsnge of 0.6 to 1.02. Sample calibrations of the installation at M= 0.6, 0.81, and 0.92 me given in figuree 13. These data, as well as those at the other test speeds, show a linear vsriation of local angle of attack with true angle ‘- of attack. The data also show that for constant angle of attack the local angle of attack decreases as the Mach number increases. In addi- - tion, the local angle of attack is shown to chsmge about 1.6° for each degree change in true angle of attack. Faother locations of the sensor on the nose and for other fuselage nose shapes, the variations of locsl singleof attack with true angle of attack will, of course, be different." The variations are mostly due to mach effects in this document. This is expected; compressibility is Bad! But what is really important is the corelation between actual AOA and measured AOA is maintained. This perfectly applies to the Mig 21 and the UUA. Based On my data, I show that as the UUA is maintained (within 1 unit below mach 0.8 ) it doesn't maintain a stable AOA. We are talking about 1-2 degrees difference; this isn't very significant, but that is noticeable. This could be explained by Bad uua logic, Bad AOA logic (not as if there are no bugs in DCS :cry: ), or mach effects/actual probe errors. This makes the calculations potentially out of place. However, As the UUA is maintained, the CL increases with a reduction of speed; it shouldn't. But if we look at this through the AOA, as the AOA reduces, the CL Increases; it shouldn't. So wichever way we look at this data, it just doesn't work. Which would tend to confirm the current flight model Is way off. There is a last note I have to point out. During testing, I found a discrepancy between the reported fuel level between DCS and the one reported by tacview. I used the one reported by tacview. It was showing more than the one reported by DCS; therefore it is likely to contribute toward the higher found CL. 6284.4 was FF with tacview; 5027 was FF with DCS. This could possibly contribute to a false reported 6% performance gain. Edit: added UUA 28 info. Similar result found. DCS Mig 21 FM testing.zip

https://forums.eagle.ru/showpost.php?p=3457419&postcount=2 On page 54/55, there is the description Of the UUA. It clearly states that the UUA "IS" the AOA and it is not variable it just is data as is the speed, altitude... It makes sense to find a correlation between the two in DCS! I will try to get some DCS data tomorrow and make it stick together. But right now I think we are creating issues with that UUA that are not actually present. Edit: Due to the positioning/Flow error on the vane, there is a discrepency between actual AOA and UUA indication. Similar to the difference between Calibrated and true airspeed. This difference doesn't prevent one given unit UUA to allways be equal to a same AOA. https://forums.eagle.ru/attachment.php?attachmentid=105667&d=1412951059 This article might help shed some light.

I am really not quite sure to understand what the issue is. Just because it probably is something trivial, let's go back to basics. On your said calculated chart (not actual data if I understand correctly), I see mostly everything being coherent (more on that later). On a given wing, at a given angle of attack, the CL should remain constant. That's actually true for low speeds, but as we get into compressability issues (higher mach), the CL can change slightly hence the bump on the chart. As this angle of attack should be "fixed" I do not see why we have a static UUA and a variable AOA. This just doesn't make sense to me. As such, I would tend to think that something is leading you to believe the AOA should change. I think If you could tell me more as to why this aoa value is changing, we could nail this data. Based on my very limited testing in DCS, I see perfect correlation between UUA and AOA irrespective of the speed. As it should be according to the DCS mig manual. As for the achievement logo... hum... something like a kerbal test pilot would make sense I think :P

To me I don't see any issue in respect to UUA vs AOA... it seems to be linear as expected within acceptable error margin.

Thanks to you for this great piece of research. Assuming this computation is correct as is my reading, I am forced to disagree with your observations. -According to the orginial chart, below mach 0.6, @33 pull, You should be obtaining a stable CL @0.8. From your testing, it is shown at a value well above 1.2. This equals to a 50% performance gain. To me this is very very far from being negligeable. -I also think you somehow missed a few important details. That is perfectly normal when working on such advanced computing. But, you cannot put a curve For UUA @ 33 without this value being maintained. I understand this was not possible to test at low level as you would have gone well above max G. Should you wish to continue your blue curve on chart 1 past mach 0.6, you need to fly higher, this will have the effect of reducing the air density and therefore allow you to perform the tests correctly. -I know there is some very complex wording and formulas involved. When you are saying max pull, I assume you are talking about maximum stick input. This maximum stick input doesn't show anywhere on the original chart. You shall plot the max stick input based on the associated UUA, speed and CL, according to my observations, you do so solely based on a combination of speed and CL which is not scientificaly correct. What happens at this point is the g protection kicks in before you are given the chance to reach max CL. This is somehow solved in chart 2 by smartly saying telling R2D2 to sleep but, climbing would work as well. -For your testing, The UUA 21 chart seems to be using the perfect technique. Unfortunately, it shows again a gap to the actual chart between about 50% and 30% gain. IRL that would likely equate from 7g instantanuous being improved to about 9.8g. As you can see this is a very big difference to the actual aircraft. The variable that is not explicitely stated in the original chart is the altitude. The test pilots have had to fly at much higher altitude in order to obtain the values without putting their lives at risk (like pulling 20Gs :cry: ). In theory, this entire chart could be ploted flying at 1g. (very stupid to do IRL; probably even impossible.) The great values you obtained should ideally be looked at in their entirety. I stated on different points that the CL was up to 50% higher. This difference could also be explained by unprecise weight, wing area, density. But, if the entire curve manages to have a similar shape, only a coherent g load could validate the entire chart. But then, the given lift coeficient for a given aircraft is just one part of the equation. Drag, and above all controlability are critical factors to consider. According to the actual flight manual, the current flight model does not exhibit any of the caracter the real life mig 21 should have at high AOA. That's what I miss the most with the current mig21 flight model. I really thank you for your amazing dedication and work! :joystick: Unfortunately, to me all it proved if it can prove anything is that the flight model is very very far from the actual aircraft at the moment. By the way, well done on passing my reasonability check, it's not every day you see some coherent data!:book:

You don't want any opinions but, you are of the opinion I lie? Please be coherent. The delta wings do have very nice high alpha carateristics. This is allowed by the self generation of very strong vortices on the wing leading edge. Unfortunately, these vortices do produce a huge increase of drag not currently visible. Also during a stall, most aircrafts will tend to drop a wing, sometimes even exibit dutch roll. At the moment, there is none of that. The other big issue is that according to this chart provided, from 28 to 33°, it is a dangerous operating area as there is a possibility of stalling (black and red area). I haven't managed to be punished by flying in this area, or beyond... And the turn rate does actually looks beneficial. To me, It starts to be a bit too much... Drag not punishing, and flying not punishing nor challenging. As other said, it feels like flying on FBW. But, this is just my opinion whether you like it or not. As for your question, to date I have flown 23 different types. I stalled most of them. Gliders are: WA30 - SNC34 - G103 - DuoDiscus - FOX - ASK13- C201 - C101 - LS-4 (HK36 and SF28 not stalled) Airplanes are: C152 - C172 - C182RG - J3 - PA28 - GA8 - Citabria - Christen Eagle - PA30 -PA31 (CRJ200 and 900 only "stalled" in level D sim)

I agree with what has been said. The high AOA flying is a step back... One day Magnitude will learn to do flight models.... Maybe I won't be nice to Magnitude. But I think, the split was a great thing for Heatblur. Heatblur has delivered on their promises and brought one of the most glorious aircrafts in DCS. In the same timeframe magnitude has delivered a CEII; to me the worst module in DCS (which I could have been flying way more since it is a very challenging and fun aircraft IRL). They've been promising updates most notably on the CEII sounds for more than a year now... Just for a sound pack... Quite frankly I would not be surprised to see them fail in this buisness. I just hope the customers won't be harmed...