New MIRAGE 2000 Flight Model

I'm trying to understand the FBW logic.

So far we have read that below 275 kts the plane is AoA limited

and that the FBW programed AoA limit is 29 deg. (31 beyond elastic stop).

Does this mean that below 275 kts a full aft stick input should always

command a 29 AoA maneuver?

If I make a 80 deg bank hard turn (full aft stick) with full AB at low altitude, the plane will reach a maximum of about 27 AoA, which limits further the minimum speed to about 160 - 170 kts. And the speed won't drop any further

In AA mode the limits are 29 deg or 9G.

Below 275kt it is trimmed for AoA.

Above 325kt it is trimmed for G.

A mix of the 2 between those speed.

But the wings won't give enough lift to hit 9G below 350kt anyway.

Clean, the plane can hold 100kt level, near max AoA and without post combustion (during airshow 100kt with 85% rpm).

I don't know how it would end up at max AoA with full post combustion.

You mean the "tail slide"?...if so, yes, I'm also interested in knowing why we can't do it or wht this m2000 version can't do it...

Yes! I meant it. And Jojo! Su-27 and F-15 have better climbing capacity. so this behavior of the Mirage at the top point is simply unacceptable.

In AA mode the limits are 29 deg or 9G.

 

I don't know how it would end up at max AoA with full post combustion.

My question was primarly, if a full stick input in the low speed regiment should always command a 29AoA maneuver, because i can hardly reach this limit (only in high pitch up maneuvers). A level / diving hard turn ends at about 27 or 28 AoA, as in the example above.

It seems now that the 29 AoA is only the furthest limit, and the FBW sets a variable stricter limit within the flight envelope.

And what about the 31AoA hard stop limit, does it perform the same way? So a full stick beyond the elastic stop will always command a 31 AoA (or 11g) or would it command 2 more AoA deg for a specific flight condition (in later case i don't see how it would fulfill the designed purpose)?

Yes! I meant it. And Jojo! Su-27 and F-15 have better climbing capacity. so this behavior of the Mirage at the top point is simply unacceptable.

Yes, when trying tail slide, it feels like the FM is not capable of it...I know thats not a proper combat maneuver but say it happens to you in a dogfight, then you are dead because that behaviour is out of the FM scope?...all ED planes have this correctly modeled so I expect the same from Razbam. Even if the 2000C is not capable of doing it due to engine/safety limitations, it doesn't mean the nose shouldnt drop down when the plane hangs in the air.

I would love to have some kind of official statement about this :)

Other than that, I'm really enjoying the new FM. Yesterday, I made a display and then watched it in the recordings as espectator using a custom camera shake and I was really impresed how realistic it behaved :thumbup:

Thanks!

Ok, tail slide doesn't end well :music_whistling:

Ok, tail slide doesn't end well :music_whistling:

Nope!:D...imho that's the last thing remaining (because I would like this to be properly implemented).

thanks!

Nope!:D...imho that's the last thing remaining (because I would like this to be properly implemented).

 

 

thanks!

I totally agree! :thumbup: :pilotfly:

Tailslide are not autorised due to engine stall risk and spin departure risk as well.

I think SOP Low speed limitation is 100Kts like the Rafale, technically can do less yes, but that's the limitation.

Go to 40 sec for tailslide ;)

Tailslide are not autorised due to engine stall risk and spin departure risk as well.

I think SOP Low speed limitation in 100Kts like the Rafale, technically can do less yes, but that's the limitation.

In that regard we're good, I did flame out and entered spin.

I managed to exit from spin and relighted the engine.

But the FBW should have taken over and prevented loss of control.

Overall, the new FM does everything else better than the previous one, excepted that. So lets wait and not focus too much of that thing outside of allowed flight envelope.

+1 I also had flameouts attempting the tailslide. What appears different in DCS vs the video is how abruptly the jet loses lift IRL. In DCS it very gradually slows them basically hangs up for a few seconds then enters a roll departure (without heavy control input). I’m not sure if it’s an issue with idle thrust being to high or something due to drag (maybe related to the excessive glide ratio?). Assuming it is in fact an issue.

The glide ratio has been fixed.

+1 I also had flameouts attempting the tailslide. What appears different in DCS vs the video is how abruptly the jet loses lift IRL. In DCS it very gradually slows them basically hangs up for a few seconds then enters a roll departure (without heavy control input). I’m not sure if it’s an issue with idle thrust being to high or something due to drag (maybe related to the excessive glide ratio?). Assuming it is in fact an issue.

Well, I can see something MUCH more different in DCS respect real life...the nose WON'T drop no matter what. I think thats a much more critical "issue" than anything else imho. Once the plane stops in the air and starts falling, it does in an impossible way, keeping the nose up at whatever the angle you leave it and spinning.

As I said, this is the LAST thing to fix in the FM, other than that FM feels AMAZING!

Hope Razbam can give us the icing on the cake with this.;)

Well, I can see something MUCH more different in DCS respect real life...the nose WON'T drop no matter what. I think thats a much more critical "issue" than anything else imho. Once the plane stops in the air and starts falling, it does in an impossible way, keeping the nose up at whatever the angle you leave it and spinning.

That too. With emergency FBW gain it seems like the control authority exists to push the nose down. Perhaps it’s a control law issue?

emergency FBW gain switch is there to deal with air sensor issues (like icing or something like that).

There is a spin switch to gain more control, it's labelled "VRILLE" left of the HUD.

I got out of my nose up spin thanks to it, but it takes time and altitude :joystick:

In which version is the new FM active?

Asking cause in 2.2.0 it feels very weird, the aircraft slowing down all pitch commands A LOT and pretty much REFUSING to drop its nose. Also the aircraft's behavior when spun out of control is incredibly unrealistic, it's like physics.exe simply seized working. In short the Mirage is very dissatisfactory to fly in 2.2.0 IMHO.

I hope RAZBAM will fix it cause I know they can make excellent FM's, the Harrier being the perfect example, absolutely loving that bird.

Well I must say I also am still in dubio about the new FM. Very good in dogfights for sure, as you can out turn everyone. But the stick controls are just so unnatural and so at odds with what we are used to, it seems like you are flying an airliner, certainly at low altitude where it is almost unflyable. Indeed pitch down is simply bizarre, that just cannot be right. In a dive it is difficult to precisely control the aircraft, eg in a rocket run. (Of course that was not the role the M2000C was designed for).

You have to trim with the new FM. That's the main point.

Well I must say I also am still in dubio about the new FM. Very good in dogfights for sure, as you can out turn everyone. But the stick controls are just so unnatural and so at odds with what we are used to, it seems like you are flying an airliner, certainly at low altitude where it is almost unflyable. Indeed pitch down is simply bizarre, that just cannot be right. In a dive it is difficult to precisely control the aircraft, eg in a rocket run. (Of course that was not the role the M2000C was designed for).

Sorry mate, but its been explained thats due to how real plane stick works (not equal deflection for positive and negative input)...anyway I can ASSURE you its a matter of get used to it...I have PERFECT control over it after just a few hours of flight and its even A LOT better than before because its way more accurate than before while at the same time you can be as hard as you want in a dogfight so please, don't blame what is right.:)

Seriously mate, give it some time and you will change your mind no doubt!!:thumbup:

The only complain I have right now is the tail slide FM which is obviously out of realism...other than that Im really enjoying the new FM and the new controls.

I really can't enjoy it like this, it's so damn unresponsive, and that the nose just refuses to drop is incredibly frustrating to fly with. I really hope it isn't supposed to be like that, but if so then I'll just have to quit flying it as I did the Su-27, it's just a real shame. That said realism should always trumph preferences, so I don't want them to fix it if that's actually how the real bird reacts, I'd just find it incredibly odd if it did.

It looks like you don't like to use trim. Indeed you have to trim Su 27 and M-2000. In the case of the M-2000C you especially need to trim below 300kt.

Above 300kt the plane is trimmed for G (it will try to keep constant G load).

Below 300kt the plane is trimmed for AoA (it will try to keep the same AoA)

Why unresponsive ? When does the nose "refuse to drop" ?

It's still rolling as fast, still sustaining 9G at low altitude and it goes there fast.

If you had custom axes setting think to reset them.

In a dive it is difficult to precisely control the aircraft, eg in a rocket run. (Of course that was not the role the M2000C was designed for).

Significative change indeed but it's more realistic. I did some bomb runs this afternoon and you need more discipline to control your speed and trim the aircraft during the run.

I really can't enjoy it like this, it's so damn unresponsive, and that the nose just refuses to drop is incredibly frustrating to fly with. I really hope it isn't supposed to be like that, but if so then I'll just have to quit flying it as I did the Su-27, it's just a real shame. That said realism should always trumph preferences, so I don't want them to fix it if that's actually how the real bird reacts, I'd just find it incredibly odd if it did.

I didn't like the sluggish feeling either when pushing the nose down but but giving it some nose down trim does take away that feeling of resistance. Taking some getting used to, like others have pointed out, but I'm starting to get the hang of it.

PS for the trim using the Autopilot, do you guys put the AP constantly on and use the AP standby button when you manoevre?

AP constantly on and use the AP standby button when you manoevre

Exactly that.

Only disconnecting autopilot for:

- Aerial refueling

- Landing passing 200ft AGL.

- After the merge, BFM

- Ground pounding