Nose down AB and do not acelerate?????

F-5E AI has better performance? AI can get better power on the climb? This is not right.

I saw this on some dogfights.

30° dive, Full AB, 150 knots, AOA 18°, and 1.6 G

 

In this attitude the aircraft loss speed.

And it's doesn't seem weird to me that it does.

UNLOAD the bloody thing to let it fly again. :pilotfly:

You have Velocity Vector and Energy carets in you HUD. Use them! :detective:

I think a conversation between the team and some M-2000 pilot could at least reduce the mistakes without compromising the secrecy. This is because the team has competence to understand what the professional describes, it would be something more technical than this our debate.

Why do you seem to think this isn't already in place? :smartass:

Oh, and BTW, I believe "the team" has professionals in it, too ;) Look for "Meet the team" topic :book:

F-5E AI has better performance? AI can get better power on the climb? This is not right.

AI use a Simplified Flight Model.

I know if Unload I will recover speed. I only make a test and think that it is exaggerated.

Thanks to the information about AI. I will set it with less performance, it was in excellent.

Thanks Azrayen

Enviado de meu MotoG3 usando Tapatalk

Even with FBW it is possible to drain off enough speed to stall the aircraft and depart from controlled flight and enter an unrecoverable spin, under these conditions even full AB will not do much unless you can bring the aircraft back within the flight envelope.

 

Not saying that this definitely isnt caused by bugs in the FM, just that nothing described is outside of the realms of physical possibility.

 

If the velocity vector is within the HUD when you are powering towards the ground and not picking up speed, then its definitely the FM. If the VV is not in the HUD, you have probably departed.

 

NB: Im not sure how the engine and thrust is modelled, but if you are at say, 90deg AoA, the engine may not be producing all the thrust it can, even with full AB. This is due to problems getting air to flow into the intake.

The FBW is designed to limit the maximum AoA to 29°. But even there, the drag is so high that even with after burner you bleed energy.

But if you never release the stick, you end up a sitting duck without speed.

In theory, the only way to go past 29° with fully serviceable FBW is to go vertical and let bleed the speed nose up. But even there you should recover gently.

It should go nose down by itself, and you should let it build up speed before pulling the stick.

But I have to experiment on my part to see what's the issue since I don't see video or track in this report...

Tested again:

 

30° dive, Full AB, 150 knots, AOA 18°, and 1.6 G

 

In this attitude the aircraft loss speed.

Look at this ESTIMATED chart (not the real one).

This is for 15 000ft.

You will that at 150kt, close to 2G you're on "0" line. Which mean that even with full afterburner, you can just hope to keep your speed. And this horizontal turn.

You're trying to recover from a 30° dive without enough speed.

im new to the Mirage. i got it a couple of days before the last update and only had time to fly it very basically in the previous version of dcs. still i directely had the feeling the plane had lost some Power in a wierd way after the update. as a new plane owner i had been buzzing around the hills and cities and making a couple of landings and doing the training missions just to get the feel of the controlls etc. Before the update i landed with no problem for example.. after the update its damn near impossible and that loss of Power at high AoA at low speed seems directely linked to my constant failures (and that forward noosewheel "spring" bug too ofc -but thats Another matter) as the plane has a tendency to drop like a stone during the latter stadges of the approach and need full AP to not crash (im still learing the landing but this is Before/after patch im talking about).

i also feel that the A10C have lost some Power after the update and that is my "main" plane and i have flewn it a lot last months. it just feels like dcs world has changed someting with drag/weight etc.. that wierd Rolling in AP while in a orbit you get might also be related to some kind of AoA loss of speed?

i would very much like to get more comments on what ppl "feel" and less technical pointers. just get in the planes and do what ever you did Before the update and see if it feels different.

Well, if you're new to the M2000C you might need some handling tips for landing.

But if you don't want, i won't :smilewink:

I fly the 2000 since it's out and I did not feel any drag change in the last update.

It is maybe the third or fourth time that someone say this in this thread but provide us a track !! We don't know if your issues are because of bug or bad flying or procedure.

I will not help here anymore unless someone provide à video or a track to back the issue.

F-5E AI has better performance? AI can get better power on the climb? This is not right.

 

I saw this on some dogfights.

F-5 AI is broken at this moment, He can climb and accelerate passing mach 1.0 at same time... Fortunatly the client FM can´t do this.

I fly the 2000 since it's out and I did not feel any drag change in the last update.

 

It is maybe the third or fourth time that someone say this in this thread but provide us a track !! We don't know if your issues are because of bug or bad flying or procedure.

 

I will not help here anymore unless someone provide à video or a track to back the issue.

I detected it in the update before the last one - 2.x.x.

Ok guys, I asked my fighter pilot friend to test the module, I attached the trk of his flight.

His conclusions, according to what he can speak without compromising the secrecy. It is in agreement with the graph posted here in the forum, which is not totally wrong, but the performance is a bit degraded.

According to him, the 2000 supports 9 g at 10000 ft and still accelerate a little without external store, the limit is the resistance of the pilot.

The reason that the energy is degraded is a bit accelerated in DCS.

Small adjustments are needed, it's almost there

M2000 IPEV.trk

We used F-5E in excellent mode.

According to him, the 2000 supports 9 g at 10000 ft and still accelerate a little without external store, the limit is the resistance of the pilot.

At what speed does the aircraft sustain 9G ?

Currently going 500kts+ the aircraft sustain 9G+. When we are talking G the speed is very important because taking 9G at 200kts will give you a very sharp turn(and kill your energy) whereas 9G at 550kts will just give pain to your pilot :D.

It is great to have feedback from your pilot friend but it have to be a bit more precise that that :).

Ok guys, i want to demonstrate what's the problem we're speaking about.

I made a short tacview and a video and you can check it as the plane stop accelerating as it comes at low speeds and AOA more than 20°

Now the point is: loosing speed with high AOA is theorically correct, but it's more proportional to our IAS, more is the air pressure on the high angled wings and more is the drag force component. As our IAS become lower and less drag force we will have from the high angled wings.

Point two: high AOA reduces the pressure of the air into the turbine intakes, theorically true, but reducing it doesn't mean to have less thrust than the thrust we have on the runway when we takeoff. The pressure can be reduced, but we have to consider that before takeoff that's equal to ZERO and the engine is still capable to give us thrust and to take enough air to light on the Afterburner without stalling.

In this video i show you how the effects described are strong, and exagerated, the plane is with a clear loadout.

I make a split-S pulling high AOA and loosing energy until i stall, i level the plane, with negative pitch in full AB and the plane still doesn't accelerate even if my IAS is lower than the speed i can even reach with my car (180kmh). I push the nose down to gain some speed then i pull again to put my FPM on the horizon level, i'm leveled and the plane still slows... then, to save me from a certain crash i make a halfway roll, and as my AOA go to zero the plane soars like a rocket.

You can check telemetry and all the datas on the tacview attached.

Tacview-20170418-125111-DCS.zip.rar

Hi guys, I'm keeping an eye on this and will be looking into it. I believe there to be an issue in too severe of a drag build up both pitch rate derivative coefficients and in alpha rate derivative coefficients at mid to high angles of attack that is causing it. It's fairly complex and need to be graceful how I solve it but just wanted to chime in that I'm on the case :)

Brilliant :thumbup:

I did a quick look on the video and I noticed that you put the velocity vector indicator on the horizon, but at your high AoA the VVI does not indicate where you plane is going because your aircraft velocity vector is out of the HUD.

To me this is normal behavior, at 20°+ AoA you won't go gain speed, the only way to do so is to unload the plane and thus lower the AoA. Classic "plane pancaking" :D but I might be wrong.

Anyway I will look the tacview and the video in more details when I have time, thank you very much for doing this :).

I will ask him about speed.

Falconzx, Great video.

The VVI lower limit is currently too high (except in APP mode).

That's a reported issue, already.

While waiting for it to be fixed, beware of it ;)

Sustaining 9G at 10000' should be physically impossible. :D

At what speed does the aircraft sustain 9G ?

Currently going 500kts+ the aircraft sustain 9G+. When we are talking G the speed is very important because taking 9G at 200kts will give you a very sharp turn(and kill your energy) whereas 9G at 550kts will just give pain to your pilot :D.

 

It is great to have feedback from your pilot friend but it have to be a bit more precise that that :).

Hi guys, I'm keeping an eye on this and will be looking into it. I believe there to be an issue in too severe of a drag build up both pitch rate derivative coefficients and in alpha rate derivative coefficients at mid to high angles of attack that is causing it. It's fairly complex and need to be graceful how I solve it but just wanted to chime in that I'm on the case :)

thank you so much !

I did a quick look on the video and I noticed that you put the velocity vector indicator on the horizon, but at your high AoA the VVI does not indicate where you plane is going because your aircraft velocity vector is out of the HUD.

 

To me this is normal behavior, at 20°+ AoA you won't go gain speed, the only way to do so is to unload the plane and thus lower the AoA. Classic "plane pancaking" :D but I might be wrong.

 

Anyway I will look the tacview and the video in more details when I have time, thank you very much for doing this :).

True the VVI is wrong and you can see it from the tacview! What i wanted to demonstrate was the excessive drag, the plane was literally falling down, because i was in a stall, stall means you don't have enough air pressure under the wings to lift you up, in a condition like that it's so strange to not having thrust. Just do the same manouver with a Su-27 and see what happens, i did it, and the plane behaviour is so natural. In particular on su27 you can really feel the Earth gravity: when your nose face the ground, even if you got without FBW and you pull, it's harder to lose speed like the M2000C does. Actually the M2000C seems to fly without gravity... if a plane stalls, should accelerate down, like a falling rock (ok not properly like a rock, you have dragging surfaces) but it's incredible that you brake in the air like that while stalling... it's like having a parachute open on my back!

Anyway if the thrust/weight ratio of those two planes (su27-m2kc) is so similar i don't expect a so evident difference at low/stall speeds, because much more at those speed the aerodynamics and the control surfaces (slats elevators) have a minor importance on the drag factors, and the behaviour should be more influenced just by the weight, and thrust.

The delta wing is a big airbrake when you are at very high AoA, it is not unreal to me.

True the VVI is wrong and you can see it from the tacview! What i wanted to demonstrate was the excessive drag, the plane was literally falling down, because i was in a stall, stall means you don't have enough air pressure under the wings to lift you up, in a condition like that it's so strange to not having thrust. Just do the same manouver with a Su-27 and see what happens, i did it, and the plane behaviour is so natural. In particular on su27 you can really feel the Earth gravity: when your nose face the ground, even if you got without FBW and you pull, it's harder to lose speed like the M2000C does. Actually the M2000C seems to fly without gravity... if a plane stalls, should accelerate down, like a falling rock (ok not properly like a rock, you have dragging surfaces) but it's incredible that you brake in the air like that while stalling... it's like having a parachute open on my back!

 

Anyway if the thrust/weight ratio of those two planes (su27-m2kc) is so similar i don't expect a so evident difference at low/stall speeds, because much more at those speed the aerodynamics and the control surfaces (slats elevators) have a minor importance on the drag factors, and the behaviour should be more influenced just by the weight, and thrust.

You're not in stall, because the FBW prevent you from it.

Just release the stick and the plane will accelerate, no need to go inverted.

You can also "unload" the plane to ease the speed recovery (push the stick to 0G, but be careful not to push into the ground).

There is an AoA where the FPM is at its down limit and no longer represent the true flight path.

As a matter of fact, with fuel below 5000kg the Su 27 will often have a thrust to weight ratio greater than that of the Mirage 2000.

Good video that will give an idea of how quick the M2000 can decelerate:

When the FPM is stuck on the pitot tube, AoA > 16°

Last question: what is your real world aeronautical experience ?

Hi guys, I'm keeping an eye on this and will be looking into it. I believe there to be an issue in too severe of a drag build up both pitch rate derivative coefficients and in alpha rate derivative coefficients at mid to high angles of attack that is causing it. It's fairly complex and need to be graceful how I solve it but just wanted to chime in that I'm on the case :)

Thanks CptSmiley,

Nice to know that me and a couple of others are not imagining this despite the "fanboy" reaction.

We can only advise what we experience and it is sometimes difficult to pin it down except to say that something is different and reacts differently to what is expected or different from previous versions.

Looking forward as usual to your expertise.

Cheers,

Cats . . .

Ok guys, i want to demonstrate what's the problem we're speaking about.

 

I made a short tacview and a video and you can check it as the plane stop accelerating as it comes at low speeds and AOA more than 20°

Now the point is: loosing speed with high AOA is theorically correct, but it's more proportional to our IAS, more is the air pressure on the high angled wings and more is the drag force component. As our IAS become lower and less drag force we will have from the high angled wings.

 

Point two: high AOA reduces the pressure of the air into the turbine intakes, theorically true, but reducing it doesn't mean to have less thrust than the thrust we have on the runway when we takeoff. The pressure can be reduced, but we have to consider that before takeoff that's equal to ZERO and the engine is still capable to give us thrust and to take enough air to light on the Afterburner without stalling.

 

 

In this video i show you how the effects described are strong, and exagerated, the plane is with a clear loadout.

I make a split-S pulling high AOA and loosing energy until i stall, i level the plane, with negative pitch in full AB and the plane still doesn't accelerate even if my IAS is lower than the speed i can even reach with my car (180kmh). I push the nose down to gain some speed then i pull again to put my FPM on the horizon level, i'm leveled and the plane still slows... then, to save me from a certain crash i make a halfway roll, and as my AOA go to zero the plane soars like a rocket.

 

You can check telemetry and all the datas on the tacview attached.

 

Thank you Falconzx,

This is exactly what I have experienced several times but not able to put it into words.

Your link does not work.

Thanks,

Cats . . .