Autopilot: elevator spikes during climbing turns

[teopereira 25]

I'm running P3D V3 and ActiveSky Next (with "enhanced turbulence" off)... The elevator spikes a lot when the autopilot is on and I'm in a climbing turn... This is something I noted long ago when I used FSX and the problem continues in P3D V3... I clicked "control spike elimination" in FSUIPC, but the problem continues... Any ideas?

 

Thanks!

[scandinavian13 5,192]

I'm running P3D V3 and ActiveSky Next (with "enhanced turbulence" off)... The elevator spikes a lot when the autopilot is on and I'm in a climbing turn... This is something I noted long ago when I used FSX and the problem continues in P3D V3... I clicked "control spike elimination" in FSUIPC, but the problem continues... Any ideas?

 

Thanks!

 

Have a hardware trim axis assigned?

[teopereira 25]

No, I have no hardware trim axis assigned.

I recorded a video showing the spikes... Spikes begin at 1:30...

 

https://www.youtube.com/watch?v=TlnXwUZ3pL4

[Budbud 227]

Hi,

 

It really looks like some turbulence effects. Have you tried to reproduce the same with no weather (active sky off and calm weather loaded in P3D)?

 

Also, maybe not related but you have a warning going off at 00:28 during the takeoff roll and that remains until the end of the video. What is it?

[scandinavian13 5,192]

 

 

No, I have no hardware trim axis assigned.
I recorded a video showing the spikes... Spikes begin at 1:30...

 

Looks very much like a hardware axis being assigned, honestly. These can occasionally be added without your knowledge, so it's worth a look.

 

If it's not that, then it might be hardware spikes. Unplug your hardware when it begins to do it. If it stops, then it's your hardware.

[teopereira 25]

Hi,

 

It really looks like some turbulence effects. Have you tried to reproduce the same with no weather (active sky off and calm weather loaded in P3D)?

 

Also, maybe not related but you have a warning going off at 00:28 during the takeoff roll and that remains until the end of the video. What is it?

 

Yes, it's due to the turbulence effect of Active Sky Next... The warning light was due to a bleed trip off...

 

Looks very much like a hardware axis being assigned, honestly. These can occasionally be added without your knowledge, so it's worth a look.

 

If it's not that, then it might be hardware spikes. Unplug your hardware when it begins to do it. If it stops, then it's your hardware.

 

After some experiments I concluded the overreaction of the elevators has to do with the Active Sky Next turbulence... I set realistic figures in the Active Sky Next turbulence. Don't know which one has fault in this case of overreaction, whether ASN or the NGX...

[scandinavian13 5,192]

Yes, it's due to the turbulence effect of Active Sky Next... The warning light was due to a bleed trip off...

 

 

 

After some experiments I concluded the overreaction of the elevators has to do with the Active Sky Next turbulence... I set realistic figures in the Active Sky Next turbulence. Don't know which one has fault in this case of overreaction, whether ASN or the NGX...

If you're handing it unrealistic scenarios then you can't expect the NGX to behave realistically. I know we included a write up on "turbulence" in the 777 Intro Manual, but I can't remember if it's in the NGX's as well. Either way, turbulence in the sim has the potential to hit the plane with forces in excess of 2Gs instantaneously. Adjust the sliders and you should be fine.

[teopereira 25]

If you're handing it unrealistic scenarios then you can't expect the NGX to behave realistically. I know we included a write up on "turbulence" in the 777 Intro Manual, but I can't remember if it's in the NGX's as well. Either way, turbulence in the sim has the potential to hit the plane with forces in excess of 2Gs instantaneously. Adjust the sliders and you should be fine.

 

Turbulence is set to 70% in the "turbulence scale effect" of ASN, which is realistic. Maximum downdraft/updraft rate is set to almost "2000 ft/min", although in the real world some updrafts and downdrafts can achieve 4000 ft/min or more...

 

Flying "by hand", the NGX doesn't oscillates at all... So I want to report this problem to the development team: the NGX autopilot, especially in the NAV mode, can't cope with ASN turbulence appropriately. Don't know whether it's a bug in NGX or in Prepar3d, but the thing is that an autopilot shouldn't behave this way...

 

And this is not the only problem between ASN and NGX: the NGX can't cope with the ASN "enhanced turbulence". It behaves weirdly...

 

Thanks!

[downscc 1,327]

My 'bump' effects in ASN are all set to 25%, not sure why you claim 70% is realistic.

 

The simulator does not have realistic turbulence, it is a shame but there's just no way the air behaves like it has no mass and moves instantly.

[teopereira 25]

My 'bump' effects in ASN are all set to 25%, not sure why you claim 70% is realistic.

 

The simulator does not have realistic turbulence, it is a shame but there's just no way the air behaves like it has no mass and moves instantly.

The default value of the "turbulence scale effect" of ASN is 70%... 70% is not a strong turbulence, is normal turbulence... Flying by hand goes without any "bumbs" or great anormal "Gs"...  But the NGX autopilot can't cope with this normal turbulence from ASN and the NGX's elevator overreacts a lot on climbing turns... Come on, guys, even the real 737 NG has some bugs, why the NGX wound't have any conflict with another software?