New Mig29 FM

[escaner]

Yesterday, during the fight with the F-18 at low altitude, I was unable to maneuver it in any way. MiG barely held on to the air. Generally MiG-29 is very demanding, which is in contradiction with the opinions of pilots.

 

I had something like this at higher altitude over the mountains (3000-4000m I guess). I lost most of the pitch authority and almost crashed. Not sure if that was a Mach or AoA issue, I still need to make my way around the cockpit. Speed was 800-900 Km/h.

[Heiner76]

FC3 owner here.

 

 

Is the updated Mig already released?

[Vitormouraa]

Yes.

[Heiner76]

Yes.

 

 

hmm.. because I didn´t receive any updates via the DCS updater.

[Vitormouraa]

Make sure you're running OpenBeta.

[Heiner76]

Ahhh,this explains it. I´m not in the Open beta. ( didn´t have more space on my HDD)

 

 

 

Thanks. Will wait for the official release.

[Lixma 06]

Ahhh,this explains it. I´m not in the Open beta. ( didn´t have more space on my HDD)

 

 

 

Thanks. Will wait for the official release.

 

You don't need a separate install for the open beta (although that is one option) - you can use this utility...

 

https://forums.eagle.ru/showthread.php?t=160053

 

...to flip back and forward between stable and beta. I usually stick with the official stable release but made an exception for the Mig.

[escaner]

I would not update right now. There is a bug in OB that might render all your current keybindings useless. Or at least check it out first.

[lipas70]

Can we stop offtop ?

[Svend_Dellepude]

You're right! It took me a while to sort this out, but that's exactly what it is. At about 10 degrees AoA, regardless of speed or G force, the LE slats deploy and there's a sudden increase of roughly 1g, and the turn tightens.

Other people have remarked about this--and that's exactly what causes it. Not a bug or flaw in the flight model at all.

 

 

Now, I'm not sure if the sudden deployment is how the slats work on the real MiG-29, or if they deploy gradually as you pull the stick back. But, that's what's happening.

 

 

 

AD

 

Noticed this as well. It seems like they are either on or off at the moment regardles of their visual position. Maybe they havn't been fully implemented in the FM yet.

[Vitormouraa]

Not sure if it was in the changelog or the newsletter but they mentioned that the slats have a 'true' behavior now. Not sure what it said exactly, gotta take a quick look at it again. Not sure what that means though.

 

Perhaps now the slats are doing what they are supposed to do? I've seen some people say that some of the the leading edge devices in DCS aren't doing what they are supposed to do, like increasing the critical AoA of the wing or just increasing lift.

 

Not sure really.

[mvsgas]

Guys, look for the German Mig-29 manual, it should be 450 pages long. A lot of the stuff mention here is explained in the manual.

[Dudikoff]

Was there any conclusion on the very limited negative-g pitch level available? The horizontal control surfaces seem to have only a slightest deflection possible in that direction.

 

I find that and the throttle behavior (with that huge dead-zone) rather frustrating.

[mvsgas]

Was there any conclusion on the very limited negative-g pitch level available? The horizontal control surfaces seem to have only a slightest deflection possible in that direction

 

The German Manual states that:

[ATTACH]195930[/ATTACH]

[Dudikoff]

The German Manual states that:

 

Well, it's moving perhaps 1-2 degrees, certainly not 15 as it should, if I understood correctly.

[probad]

well in line with the established russian flying doctrine of avoiding negative g's. if you want to point your nose away, roll and pull for positive loads.

Well, it's moving perhaps 1-2 degrees, certainly not 15 as it should, if I understood correctly.

you're not accounting for the range reserved for trim.

Edited October 14, 2018 by probad

[Dudikoff]

well in line with the established russian flying doctrine of avoiding negative g's. if you want to point your nose away, roll and pull for positive loads.

 

And the Su-25/27/33 that we also have in the game are not Soviet planes? Nonsense.

[probad]

And the Su-25/27/33 that we also have in the game are not Soviet planes? Nonsense.

mig-21 as well, and bad things happen when you push negative g's in the fighters in particular. they are not designed to be flown in the negative g regime from the drawing board.

 

 

with down trim, mig-29 stab deflection is a lot closer to its maximum negative range than you suggest. keep in mind as well that stab deflection is scheduled to airspeed, so there are only certain points in the flight envelope you can achieve maximum deflection.

 

it doesn't matter what you believe is nonsense, reality says things are done differently. western aircraft are capable of bunting, but the russians are not nato and they tailor their aircraft designs to fit their own way of flying.

 

 

edit: the slab pivot is set at an angle to the aircraft centerline and so if slab deflection is measured off the true pivot axis then it produces higher angles than viewed directly from the side.

Edited October 14, 2018 by probad

[rrohde]

Was there any conclusion on the very limited negative-g pitch level available?

 

Trim nose-down works really well for me.

[mvsgas]

Well, it's moving perhaps 1-2 degrees, certainly not 15 as it should, if I understood correctly.

 

It also says only 5°45' near the ground from 470 to 650 Knots True Air Speed (KTAS)

At what speed and altitude are you testing? How are you measuring the degrees or travel?

[Ala12Rv-watermanpc]

Just tested the MiG again, just to be sure. Definetly not placebo. It is much easyer to fly now then the first time. If it had nothing to di with the axis controls then I do not know why it started to behave differently for me. Maby I am doing somerhing differently now then the first time without releasing it.

 

Ok, thanks for the info mate, sadly it doesnt seem to work for me.

 

I lowered my axis curve from 33 (which is same for almost all DCS aircraft) to 15. Now I feel more comfortable, but doing small corrections now became difficult. Especially roll adjustments. I will try setting pitch curve 15 and keep the roll at 33.

 

I dont like to use any kind of curve for my axis, at the end of the day what you improve in some places you worsen in others so I go all the way linear.

 

I think the reason for the weird pitch behaviour is the front wing slats.

 

To test - put yourself in a steady turn at, say, 750kph look behind you and watch your wings. Now start very gradually increasing back-pressure on the stick - sloooowly tightening the turn (and increasing your AoA). At some point the slats will deploy and *bang* the nose pitches up violently.

 

 

I think you have a point on this...as soon as the slats deploy the extreme pitch up behaviour takes place...looking at some real life videos that behaviour doesnt seem to happen when the slats are deployed:

 

 

to me, it looks like there is not a sudden pitch up when hte slats are extended in this video (and others)

[mvsgas]

I think you have a point on this...as soon as the slats deploy the extreme pitch up behaviour takes place...looking at some real life videos that behaviour doesnt seem to happen when the slats are deployed:

to me, it looks like there is not a sudden pitch up when hte slats are extended in this video (and others)

Yeah but RL pilots of the mig-29 look like this :joystick:

 

 

Look at the Hydraulic gauges here

k6oqAgFZb74

 

So, what I am trying to say: How much of it is the aircraft modeling? How much of it is RL aircraft behavior? How much is the feed back possible to us in DCS to counteract some effect? Lastly, how much of it is their self impose modeling accuracy limitation Wags mentions?

 

Look how much the pilot moves the stick with the AOA high enough to extend the LEF

Starting at :20 and at 6:52. Also note how much he trims when landing.

Edited October 15, 2018 by mvsgas

[Dudikoff]

mig-21 as well, and bad things happen when you push negative g's in the fighters in particular. they are not designed to be flown in the negative g regime from the drawing board.

 

with down trim, mig-29 stab deflection is a lot closer to its maximum negative range than you suggest. keep in mind as well that stab deflection is scheduled to airspeed, so there are only certain points in the flight envelope you can achieve maximum deflection.

 

it doesn't matter what you believe is nonsense, reality says things are done differently. western aircraft are capable of bunting, but the russians are not nato and they tailor their aircraft designs to fit their own way of flying.

 

edit: the slab pivot is set at an angle to the aircraft centerline and so if slab deflection is measured off the true pivot axis then it produces higher angles than viewed directly from the side.

 

I'll play with the trim settings and compare how it influences the deflection, but if I had that much of deflection as your pictures show, I probably wouldn't be writing any of this. I was landing so the speed was relatively low and still when I checked from the side view, it would barely budge a bit over it's nominal position (which matches the hull extension for the stabilators) while I'm pushing the stick hard forward. At some points during the landing, it was basically impossible to bring the nose down at all. I'll try to get a screenshot next time I encounter this problem to compare.

 

It appeared exactly the same as the deflection I had at higher speeds, but at lower speeds it felt a bit more responsive.

Edited October 15, 2018 by Dudikoff

[probad]

I'll play with the trim settings and compare how it influences the deflection, but if I had that much of deflection as your pictures show, I probably wouldn't be writing any of this.

in the mig-29 pitchdown trim accounts for like 70% [80%, see below] of the total possible deflection physically possible for the slabs -- but it is reserved for trim only. actual pilot input pitchdown deflection is NOT 15 degrees. 15 degrees cited in the manual is maximum deflection, not deflection available to input.

 

input + trim reserve = max deflection.

 

why do you need to push nose down during landing anyways? sounds like improper technique. if you're properly trimmed, you shouldn't need to make major attitude changes.

 

edit:

although there's nothing im reading that asserts that trim range precludes input authority range. would be interesting to hear from yoyo on how this is properly interpreted.

Edited October 15, 2018 by probad

[Dudikoff]

in the mig-29 pitchdown trim accounts for like 70% [80%, see below] of the total possible deflection physically possible for the slabs -- but it is reserved for trim only. actual pilot input pitchdown deflection is NOT 15 degrees. 15 degrees cited in the manual is maximum deflection, not deflection available to input.

 

True, but I only ever saw a very slight deflection, especially at higher speed. I guess most of the negative pitch handling for the amount I was pulling was done by wing slats, hence why the horizontal surfaces didn't deflect much.

 

I guess the limits I was experiencing were mainly caused by the somewhat insensitive FSSB stick which I'm afraid to push too much as it's not mounted, plus the TM grips have a weak point there at the base. When I tried it with the keyboard, I could achieve noticeably higher deflection by somewhat longer presses of the pitch down key.

 

But, I haven't experienced the same complete lack of negative pitch control as yesterday yet, so have no screenshots to post.

Edited October 16, 2018 by Dudikoff