investigating Pure left rolling inputs also generate abnormal pitch down

[85th_Maverick]

Whenever you roll to the left, the plane also reduces it's AoA a bit or goes towars more negative, but if you roll right, your AoA stays the same. Yes, not a confusion or error due to how I handle the stick as I'm carefully applying pure roll inputs without any pitch (the small deadzone I have also helps proving it), as the keyboard commands give the same results. Don't need a track as everyone can test it and see it quite quickly, but if needed, I'll make a track which also show the inputs values.

[RuskyV]

Is this with a clean configuration?

[Furiz]

4 hours ago, 85th_Maverick said:

Whenever you roll to the left, the plane also reduces it's AoA a bit or goes towars more negative, but if you roll right, your AoA stays the same. Yes, not a confusion or error due to how I handle the stick as I'm carefully applying pure roll inputs without any pitch (the small deadzone I have also helps proving it), as the keyboard commands give the same results. Don't need a track as everyone can test it and see it quite quickly, but if needed, I'll make a track which also show the inputs values.

Best is to do what this thread says when reporting bugs, specially something like that:

 

[85th_Maverick]

4 hours ago, Furiz said:

Best is to do what this thread says when reporting bugs, specially something like that:

 

Copy that! Will do then.

[85th_Maverick]

Here it is:

left rolling generates more down pitching than right rolling.trk

I've done the test at high altitude (lower overall Reynolds number) because this strange effect is more obvious there.

This isn't a big FM issue, but shows something that shouldn't be normal! Cheers!

[Burt]

Yup ! A loose goose 

[85th_Maverick]

On 8/11/2022 at 12:27 AM, Burt said:

Yup ! A loose goose 

=))! Yeah..., something like that! And this loose goose in the FM gets more evident at higher altitude and heavier loadout (bombs, 3 CBU 97's, etc.). Test it yourself! I mean it was straight forward to notice it from the first flights I've done in the F-16 with higher loadout and higher altitude when simply rolling left and right. I thought that it was me also pushing when rolling left and not pushing when rolling right, but no..., it wasn't me as the same happens even when using the keyboard. It's not a big issue, but shows something wrong! Take your time ED, I love you!

Cheers!

[FusRoPotato]

I've been noticing the same starting from 3 patches ago. It's as if the right-hand side of the aircraft is abnormally heavy. 2 patches ago there was a note somewhere about fixing a weight issue, but seems an issue remains.

[85th_Maverick]

On 8/26/2022 at 3:55 AM, FusRoPotato said:

I've been noticing the same starting from 3 patches ago. It's as if the right-hand side of the aircraft is abnormally heavy. 2 patches ago there was a note somewhere about fixing a weight issue, but seems an issue remains.

Did you have the lantirn mounted? That's logic to have it roll right by itself due to the lantirn's weight the FCS doesn't compensate for that unless you select the ATT mode for the autopilot. The problem that I saw was about selft-reducing AoA when applying just pure roll inputs to the left which is different than rolling right. The left rolls reduce the AoA quite much compared to the right rolls. From how i see it there can be two reasons:

1. The FCS which is taught to reduce the AoA when applying rolls in order to reduce the inertia coupling effect. This being a pure flight control system design problem.

2. The aerodynamic part of the flight model (the nightmare of developers for correct and pure flight simulations) where the lift forces varying on the flight controls may also induce an abnormal shift in the total lift force towards the rear of the plane, thus bringing the pitching moment coefficient a little towards negative from which the AoA lowers a couple of degrees. I hope it's not an aerodynamic "bug" issue so to call it and that it's something much easier fixable regarding only the flight controls programming.

Cheers!

[FusRoPotato]

The problem exists with the aircraft completely stripped. You can get a more exaggerated effect by flying slow, putting something on the right wing, or almost cancel it out by installing pylon 4. I presume the right side of the aircraft is simply heavier due to a mistake, or color me super surprised if there exists something in the flight model generating more lift on the left side.

[RuskyV]

I’ve noticed with the latest patch that this is still present when rolling to the left. 
 

Loadout was:

lantern pod fitted

x6 mk82s 

x2 AIM120c 

x2 AIM9x 

ECM pod centrally mounted

x2 external fuel tanks 

 

Once all ordinance expended and external fuel empty, the downwards pitch was still present while rolling left. Rolling left and right quickly sees the pitch drop 2 or 3 degrees every time. I didn’t create a track as it was too big. 
 

if I have time I’ll see if I can add later.

[DummyCatz]

As far as I can tell, this is still present with 2.9.1.

[BIGNEWY]

Hi, 

we are taking a look at this internally. 

thanks