Fox One

The simulator is correct :) https://youtu.be/cm21PhxryrI?t=2114 https://youtu.be/cm21PhxryrI?t=2075

In Su-27 cockpit, with aircraft stationary on the runway I press rctrl+enter. Then make a fast, full pull of the stick. The stick in the cockpit is moving slowly. The controls indicator is moving slowly. I look over the shoulder, the stabilizer moves slowly. So what you are saying is that actually there is no relation between them? I am looking at the performance of the aircraft, that's how I noticed this the first time, then I looked at the aircraft from outside and noticed the slow moving stabilizer. In the low to medium speed range, when making a moderate to large, but quick stick movement in pitch, the aircraft is simply taking too long to respond. And of course it does that - what the simulator is seeing is that I am pulling the stick slowly. I wasn't aware of that, sorry. On my monitor in 3 different browsers with 100% zoom set, the text in my previous post appears normal in size (it looks identical with other people's posts). Maybe there is something I am not understanding correctly. I am writing this post with forum's default settings, how does this looks like?

Perhaps you should do the effort to read the description of the system from real aircraft flight manual. The "maximum SAFE AOA and G" you are talking about is taken care of by the G/AOA limiter. This limiter works with anticipation, it uses G rate and AOA rate as inputs: the faster the G or the AOA is increasing, the lower the value of G or AOA at which the limiter will engage and reject the stick forward. The "anticipation" function is obviously tuned such that it will keep the current values below the admissible level. Here are some videos with aircraft IN THE AIR where a very fast deflection rate of the stabilizer is visible. Trying to compare the deflection rate of the stabilizer visible in videos above with the simulator is truly ridiculous. It is visible from the Moon and with the naked eye the much faster deflection rate available in the real aircraft. Here I am, having to try to demonstrate the obvious... Contrary to what you think, here is why a fast deflection rate is necessary IN THE AIR. This aircraft is a long and very heavy object. That's why it has a huge angular inertia. In the videos above the pilot is making a moderate, but fast stick movement. The system understands that a response is needed ASAP, so it makes a very fast and quite large deflection of the stabilizer, the necessary pitch rate is developed quickly, then the system reacts to the developed pitch rate by returning fast the stabilizer to a position close to the initial one.

The Chinese probably have modified the original flight control system to their liking. Below is a diagram from Su-27SK flight manual showing the necessary stick position in horizontal flight. I'm not saying the simulator corresponds perfectly to this diagram, it certainly does not. However the simulator can be considered generally correct compared with the diagram: in subsonic flight if you increase speed you must push the stick forward more and more to maintain horizontal flight.

If that is true then I don't think the simulator is correct. The standard MiG-29 has negative static stability in 14-25deg AOA range (source, practical aerodynamics manual). That's why it has a system called APUS that commands an electro-hydro-mechanical device (called ARM-150) that is included in the pitch control system. This system in the 14 to 25.6deg AOA range will deflect the stabilizer to oppose any uncommanded change in AOA, making the aircraft appear to the pilot as a normal aircraft with positive static stability. The real Su-27 in the small AOA range it has from the beginning even less positive static stability than MiG-29, it is close to neutral, this is common knowledge. Should I believe the Su-27 becomes statically unstable in pitch at an AOA greater than MiG-29? Not bloody likely :D It is worth noting from the real Su-27 flight manual that in direct control mode (corresponding with pressing S in simulator) it is restricted to an AOA of no more than 10deg. Knowing this I would expect that just a few deg above the 10 deg AOA the aircraft will become neutral then unstable and pitch control will become very difficult or close to impossible. I suspect the Su-27 and possibly 33 too was deliberately made in simulator to have a higher positive static stability margin than the real aircraft. Of course this is just speculation. They have probably done that "for gameplay" purposes - if with S pressed at 12-13deg AOA pitch control would routinely be lost in simulator many people would not like it. Probably the developers are fearing too much the criticism of people with limited knowledge that are probably the majority of FC3 customers.

Just out of curiosity, what is mediocre about it in your opinion? A few examples please.

^^^ Well said. The navigation and weapon system in Su-33 simulator are an approximative representation of the real ones, but on airbrake indicator suddenly the developers felt the need to go for 100% accuracy. Make Su-33 full DCS module and then ok, delete the airbrake indicator if that is how the real aircraft is.

:doh: You are probably right, he was talking about "positive stability with speed" and I thought he was talking about "positive stability on G" !!!!!!! Have you thought that the first operational pilots on new naval MiG-29 are actually the most experienced former Su-33 pilots? Imagine the naval MiG-29 landing on carrier at night. It is flown by a very experienced pilot who has flown Su-33 for 10 years. When he is really close to the ship with like 2-3 seconds left, suddenly a light burns on the AOA indexer, when a moment ago all seemed fine. In the stress of the moment his mind involuntarily switches back to the habit aquired during years and years of practice flying the Su-33, he makes the wrong actions that leads to accident. This is an important indicator for carrier landing approach and is used under high stress conditions. A hypothesis of CONTINUITY from Su-33 to MiG-29 in how the indicator should be interpreted is A LOT more plausible than discontinuity. Who manufactures the aircraft makes no difference whatsoever, they implement the instrumentation like the customer wants. I am saying that fully aware that there is the possibility that the way the indicator works on MiG-29 was indeed changed from how it worked on Su-33. If that is indeed the case and the indicator in simulator works correctly, all I can say is that I am more than surprised and I really don't get it.

As you probably know, the Su-27 flight control system can function in the following modes: 1. Takeoff and landing mode - position of the horizontal stabilizer is a function of stick position and pitch rate of the aircraft. 2. Flight mode - position of the horizontal stabilizer is a function of stick position, pitch rate of the aircraft and G. 3. "Rigid connection" mode - this is the exact name of it in Russian. In this mode position of the horizontal stabilizer is a function of stick position only. This is all from the flight manual of the real aircraft, it is not "my opinion". What you are referring to as an "overriding program" is the Rigid connection mode (the ЖEСTК СВЯЗЬ switch). The purpose of this mode is to give the pilot an elementary way to control the aircraft if, despite the multiple redundancy built into the system for whatever reason the flight control system goes completely nuts. Who knows, maybe a bullet goes right through it. In this Rigid connection mode, where the position of the horizontal stabilizer is directly proportional with stick position, flight is still possible because the Su-27 is not a truly unstable aircraft. In fact the aircraft has slightly positive, close to neutral stability. If an aircraft has positive or negative stability is determined by the position of the center of pressure of the lifting surfaces in relation to the center of gravity of the aircraft. So NO, you don't change the aircraft from negative stability to positive stability with a switch. Positive or negative stability is an aerodynamic property of the aircraft, you can't change that with a switch. If the F-16 had an Rigid connection mode, switching it you would lose control of the aircraft in seconds (or less). That is because, unlike the Su-27, the longitudinal static stability of the F-16 is waaaaaaay negative. You can't fly that aircraft without computer aid. In Su-27, flying in Rigid connection mode is not allowed at speeds greater than 600Km/h and AOA greater than 10 deg (check real flight manual, emergency procedures chapter). That is, because increasing the AOA above 10 deg, the combined center of pressure of the wing and the LERX naturally will move forward, making the aircraft first neutral then statically unstable (negative stability). Control of the aircraft will most likely be lost. The simulator might differ from that. The main point is: flying an aircraft with negative stability in Rigid connection mode is not possible. It is possible on Su-27 because it has slightly positive stability. The inclusion of the Rigid connection mode was a sane decision for the safety of the pilot and the aircraft. If that was a logical or not-so-logical decision I'll let you judge.

This makes sense, and that's what I was trying to say. The current AOA indicator in simulator is obviously controlled by the AOA value. However, because the red ^ means you have to increase speed, this is actually not an AOA indexer. It is rather a speed indexer or if you like a speed director.

^^^ Let's looks at it differently, let's pretend we don't know anything about other aircraft and all we have is Su-33. Right now in simulator on the AOA indexer the lowest red light has a ^ symbol on it that clearly tells the pilot he has to increase something. Now you tell me what the pilot has to increase and how you see the logic of it. Let's say the current implementation in simulator is correct. Now you please describe how you see the logic behind it.

^^^ Colours on the AOA indexer in simulator are correct: lowest light is red, uppermost light is yellow. However the lowest light has a ^ symbol on it. The logic behind that is that it tells the pilot that he must increase something. Since this is called an AOA indexer, this means when the red ^ light burns the pilot must increase AOA to be "on speed". But in simulator in this case the red ^ light burning means that the pilot actually has to DECREASE the AOA (and it does that by increasing speed). No I haven't but this is logics and common sense. On all US aircraft of all times and the naval MiG-29 when the lowest symbol ^ burns, this means the pilot must increase AOA to be "on speed". Now how likely is the Su-33 to have that REVERSED? Imagine this dialogue: One MiG engineer: "Our Su-33 naval pilots are used with the AOA indexer to function in a certain way. How about on the new naval MiGs we make that to work in reverse? You know, just for fun". Another engineer "This makes perfect sense, great idea!" Long story short: on Su-33 the AOA indexer should work just like in any US aircraft of any era.

I made the post because currently in simulator the AOA indexer lights ARE REVERSED, that is they don't work correctly (don't work like in reality). Quick example: currently in simulator when the upper light on the indexer burns, actually the lower light on the indexer should burn instead. That is, it should do that in order to work like it does on the real aircraft. Just read the link I provided where the REAL WORLD system is described. Please return to discuss after reading&understanding the description in the link provided.

^^^ Unfortunately it is not that file. Used to be SnapViewsDefault file, but now editing that has no effect.

Which is not correct as the link I provided clearly shows. Have you even bothered to read that? About the rest of your post, many thanks for the free lesson but I already knew all that like 2 decades ago ;)

Currently on the AOA indexer at landing approach the lowest symbol ^ shows that you have to increase speed (and lower AOA). I think in reality it works exactly as in US aircraft, that is exactly in reverse. The indexer as it is now can't even be called an "AOA indexer". It is more like a speed indexer, the ^ symbol shows that you have to increase something - what you have to increase here to achieve correct conditions is speed, which means to actually lower the AOA. http://forums.airforce.ru/matchast/4131-reestr-su-33-a-16/ Here on post #305 the MiG-29 AOA indexer is described, it seems like on Su-33 it is principially similar. The ^ symbol here clearly means the AOA must be increased.

Save Cockpit Angles (RAlt+Num0) is working but only for current mission. On next mission it will reset back to default. Anyone knows where is the file with cockpit angles that can be edited?

The existence or not of ground effect simulation can be tested in the way described here https://forums.eagle.ru/showpost.php?p=2901404&postcount=2 I performed a similar ground effect test in 1.5.6, se attached track. Flying perfectly horizontally in ground effect with a speed of 153 the AOA was 10 deg, while doing the same outside ground effect the AOA was 11.2 - 11.3 deg. Conclusion - ground effect is definitely simulated. Also the difference in AOA of 1.2 - 1.3 deg is pretty good IMO. 2000 ground effect 2.trk

It's been 1.5 years since this module went "early access". And after 1.5 years what is discussed in this thread I would describe as a VERY MAJOR flight model error. This is not nitpicking. It's an error you don't need any real world diagram to detect; you need just a little common sense. How can you realease a FM version with such aberrant behaviour? Then say "ok guys, I'm on it". You embarrass yourself if you keep doing that every week. Modules made by ED and Belsimtek never went early access with such visible from the Moon flight model inaccuracies. Have you seen any perceptible change in F-5E flight model? Even now this Mirage flight model is still not ready for early access. By now after 1.5 years this FM should be in the "final touches" phase, not with elementary stuff grossly wrong. After 1.5 years I think that's enough time to form an opinion, so I don't think I am being too harsh. For 1.5 years this FM was continuously tweaked one way or the other based on what people write on the forum. Right now this FM has ZERO credibility. I intended to write on the forum about several things that are obviously inaccurate, however I gave up. I would be only wasting my time. If the guy making the FM is not competent enough for the job and constantly needs arrows to point him in the right direction because he doesn't figures on his own obvious errors, there's really no hope. I regret very much buying this module. Lesson learned. If the FM of future modules will be made by the same guy, this is definitely my first and last Razbam module. The good side - more money will remain in my pocket.

I performed the following test. With 50% fuel at low altitude, I performed slow horizontal flight with a speed corresponding to an AOA of 20 deg. For both F-15 and Su-27 with the speed close to constant the necessary RPM was about 83-84%. With Mirage 2000 afterburner is needed. How on earth could the difference possibly be that huge? Let's pretend for a moment the Mirage FM is accurate. This would mean the aircraft could only be classified as a disaster and a complete failure. Have you ever seen a relatively recent fighter aircraft of any type needing afterburner to perform slow speed/high AOA flight? The 20 deg AOA figure is actually quite conservative, with the likes of F-16 or Mirage 2000 slow flight is routinely performed at airshows with an AOA in the 25 deg region. I really don't want to hear the "it's a delta/high drag" lecture. Yes it's a delta but not like a Mirage III delta. With the Mirage III performing slow speed/high AOA flight the elevons would be deflected upwards at a pretty considerable angle, effectively dumping lift of the platform and greatly increasing trim drag. Mirage 2000 is a relaxed static stability delta. Performing slow speed/high AOA flight the elevons are close to neutral or even deflected slightly downwards, further increasing lift, as you can clearly see here If the Mirage 2000 was really so draggy and aerodynamically inefficient at an AOA of 20 deg compared with the like of F-15, the designers would have chosen a different aerodynamic scheme. They would have figured that much, that the plane won't be competitive. But the designers knew that a delta with relaxed static stability and a wing with adaptive polar due to use of leading/trailing edge devices/control surfaces can be competitive because trim drag would be reduced very much compared with a Mirage III. Flight models is an incredibly complex and difficult task. Very very few people have the required brainpower to make a decent FM. Sadly the creator of this FM is not one of them.

60 rounds according to MiG-21F-13 flight manual.

I don't think it is. If it was, you would have to only tap W key and the limiter would be switched off. Probably would also be an animation of the switch on the left panel. But instead you have to hold W key. Since overpowering the limiter is the only other way to exceed limits, this must be what holding W does. Whether it does or does not, the fact remains that the stabilizer in simulator moves too slowly. I posted 3 videos in this thread with Su-27 aircraft just before takeoff where a stabilizer deflection rate more than 1.5 time faster than the one available in the sim is observed. In simulator the available rate is 18 deg/s (see first post). Visually I can tell you right away this is a ridiculously slow rate for any fighter aircraft from any era. MiG-29 stabilizer has an available deflection rate of 38deg/s (source, MiG-29 practical aerodynamics manual). That is more than 2 times the rate available for Su-27 in simulator. Besides being a larger and heavier aircraft than MiG-29, Su-27 also has relaxed longitudinal static stability. Fast stabilizer deflection rate is very important, if not vital. I would expect a deflection rate for Su-27 at least equal to that of MiG-29. It's engineering common sense. I timed the Su-27 deflection rate from videos and came to 30deg/s (post #1). But that is not necessarily the max rate available for the real aircraft. A pilot making a final check of the controls right before takeoff on the runway, probably does not very often check pitch control by pulling the stick fully as fast as he can. As I have already explained in this thread, the rate available in the test I performed on runway before takeoff has nothing to do with the AOA/G limiter (post #11). I repeat that even if the limiter was working in the test discussed here, the limiter is a stick stop and not some sort of a "stick damper" that slows the stick along its entire motion range. The fact that on the runway deflection test holding W key suddenly you have a rate of more than 40deg/s available does not make any sense IMO. What would make sense is if such a rate would be available without holding W key.

The explanation is simple: RAZBAM cockpit is correct and all the pictures on the internet are wrong :D

D model used Shrike missiles in Vietnam, there is plenty of photo and video evidence.