Cant get autopilot to function without the plane pitching up/nose diving?

[theskyisthelimit99]

Im sure my issue is probably because i'm still relatively new to this aircraft.  But i've watched tutorials and I was pretty sure i had been doing things correctly.

In this sample video I took off from Catalina airport after creating a flight plan in the g1000 (it seemed to save my fpl from my previous attempts) (flight to KFAT).  I go through the motions take off, get to about 5,000 feet then try to engage the auto pilot (after setting the altitude to around 11,000 feet).  immediately the plane pitches upward or usually does, until it stalls then nose dives of course.

I'm hoping there is a clue in the video as to what i'm missing.  AP Trim is set to on, i set the VS dial before turning on AP to +1500 feet per minute, then turn that button off, engage nav and press the yaw dampener and ap buttons to try to achieve and hold 10,000.

Any thoughts here, not sure if its just a glitch or something i'm doing wrong

 

 

Thanks

[Goran_M]

Check maintenance manager for any damage anywhere

[theskyisthelimit99]

30 minutes ago, Goran_M said:

Check maintenance manager for any damage anywhere

Each time I retest this I start with a new airframe to be safe. The flight plan is still there though 

[Goran_M]

Just took a quick look at your video.  The autopilot uses the trim tabs to control pitch, roll and yaw, and ur trim tabs are all good, and from what I can see, the trim is fighting against the controls.  It looks like you might have a calibration issue.  Did you double check hardware calibration and make sure you don't have any double ups in pitch control?

[theskyisthelimit99]

49 minutes ago, Goran_M said:

Just took a quick look at your video.  The autopilot uses the trim tabs to control pitch, roll and yaw, and ur trim tabs are all good, and from what I can see, the trim is fighting against the controls.  It looks like you might have a calibration issue.  Did you double check hardware calibration and make sure you don't have any double ups in pitch control?

Thanks for checking.  Yeah i was starting to think this is some sort of calibration issue (ch eclipse yoke and 2 logitech throttle quadrants with ch pedals), so i just now recalibrated everything, for a brief moment it seemed like the AP engaged properly, then about 15 seconds later it did the pitch up thing again.

I think I might try installing this to my bare install of xp11 and retest from scratch in case there is a plugin conflict of some kind.

[theskyisthelimit99]

On my clean install, the autopilot at least seems to be functioning normally.  I couldnt get it to track the flight plan magenta line, but i think I just wasnt doing it correct.

I guess i need to revisit my full install and figure out what is causing the issue, maybe starting with the joystick prf files (clearing them).

Thanks for the help to this point, i think i've narrowed it down at least, not really the planes fault of course

 

[Goran_M]

Out of curiosity, could you post your log.txt file so I can see what's going on when it's running.

[theskyisthelimit99]

Attached is a log file from a recent test i did.  I was able to do the reverse flight the other day after copying over the "clean install" joystick prf files, though there might have been a glitch i manually avoided even during that.. so this flight is a fresh test.

I also recorded the video for this flight.. i might edit this post to include it later, but basically it was cruising along fine (kfat to kavx flight plan).. i reached a set altitude of 18,000 feet.. it went to alt hold as expected.  Then a few mins later the trim wheel is seen spinning (i think towards nose down) but the aircraft pitches up.

In the log file there are various failures that occurred though (edit: i guess those showed up AFTER i did the replay, so not during the flight).  I started with a brand new air frame to be safe and had no issues getting airborn and establishing autopilot.

If you do a replay on the flight using the replay feature, you cant see any of the information screens, they are blank, hence I recorded the actual video of the flight though not sure how useful it will be.

There are some entries with "earth_nav.dat: malformed data on line 5563" in the log, possibly related to the antarctica addon area i installed which i think modified this file, not sure if its related, but maybe somewhere for me to start next time. edit: i dont think this was one of the files modified actually.  Looking at my clean install i also see this error BM900[navaiddb.c:512]: Error parsing M:\Program Files\X-Plane 11 CleanF\\Custom Scenery\Global Airports\Earth nav data\earth_nav.dat: malformed data on line 6386

I repeated this same test on the bare install with no issues.

 

Log - Copy (2).txt

Edited March 24, 2019 by theskyisthelimit99

[Goran_M]

3 hours ago, theskyisthelimit99 said:

Attached is a log file from a recent test i did.  I was able to do the reverse flight the other day after copying over the "clean install" joystick prf files, though there might have been a glitch i manually avoided even during that.. so this flight is a fresh test.

I also recorded the video for this flight.. i might edit this post to include it later, but basically it was cruising along fine (kfat to kavx flight plan).. i reached a set altitude of 18,000 feet.. it went to alt hold as expected.  Then a few mins later the trim wheel is seen spinning (i think towards nose down) but the aircraft pitches up.

In the log file there are various failures that occurred though (edit: i guess those showed up AFTER i did the replay, so not during the flight).  I started with a brand new air frame to be safe and had no issues getting airborn and establishing autopilot.

If you do a replay on the flight using the replay feature, you cant see any of the information screens, they are blank, hence I recorded the actual video of the flight though not sure how useful it will be.

There are some entries with "earth_nav.dat: malformed data on line 5563" in the log, possibly related to the antarctica addon area i installed which i think modified this file, not sure if its related, but maybe somewhere for me to start next time. edit: i dont think this was one of the files modified actually.  Looking at my clean install i also see this error BM900[navaiddb.c:512]: Error parsing M:\Program Files\X-Plane 11 CleanF\\Custom Scenery\Global Airports\Earth nav data\earth_nav.dat: malformed data on line 6386

I repeated this same test on the bare install with no issues.

 

Log - Copy (2).txt

Question:  Is your experimental flight model turned on?

[theskyisthelimit99]

43 minutes ago, Goran_M said:

Question:  Is your experimental flight model turned on?

Its not on, unfortunately (was hoping for something simple)

Here is the clip, around 10min or just thereafter is where it goes haywire (i need to get shadowplay or obs back on my system, the windows game dvr quality is rather poor).

 

I'm going to eliminate all plugins and retry, in case there might be an odd conflict there.

 

Edited March 25, 2019 by theskyisthelimit99

[Goran_M]

Please do. 

I'm racking my brain here trying to duplicate what's going on, and it's just not happening for me.

[theskyisthelimit99]

3 minutes ago, Goran_M said:

Please do. 

I'm racking my brain here trying to duplicate what's going on, and it's just not happening for me.

Im sure its a conflict of some kind and not really the tbm per say, but this is a crazy one.

I've taken out most of my plugins and mid flight, so far i've made it past the last point of failure and then some.  So I'd say either just random luck or maybe plugin related.

One thing i've noticed mid flight at least on this one, i noticed the gas caps are off (oops), nice effect of the vapor pouring backwards in the wing view.  I dont know if that was like this last time, but so far no ill effect haha

[Goran_M]

A bit of a drastic idea would be to delete your preferences and then restart X-Plane.  Downside is you would have to recalibrate everything.  

[theskyisthelimit99]

3 minutes ago, Goran_M said:

A bit of a drastic idea would be to delete your preferences and then restart X-Plane.  Downside is you would have to recalibrate everything.  

Ive kinda already done that to a degree.  I deleted the xplane.prf and replaced the joystick config ones with the clean ones from the clean install.

Just a few moments ago my pc froze completely, black screen/loss of video signal, this could be a much deeper issue.  I've lowered my overclock down a notch though it was stable 18 hours P95 with the settings i had (havent had any stability issues previously, maybe a fluke).  Will have to retest again.  EDIT: strangely after this, upon loading up the tbm again, the intro tutorial played again.

Edited March 25, 2019 by theskyisthelimit99

[Goran_M]

Another idea.  Check the maintenance manager to see you haven't got accelerated wear checked.  Check all circuit breakers.  (I'm just trying to cover all bases here)

Make sure you follow the checklists in the G1000 to make sure everything that's supposed to be on, IS on and everything that's supposed to be off, IS off.

To see it fly smoothly with no problems, and then suddenly things go haywire, tells me something is going on mid flight.

[theskyisthelimit99]

On 3/24/2019 at 11:28 PM, Goran_M said:

Another idea.  Check the maintenance manager to see you haven't got accelerated wear checked.  Check all circuit breakers.  (I'm just trying to cover all bases here)

Make sure you follow the checklists in the G1000 to make sure everything that's supposed to be on, IS on and everything that's supposed to be off, IS off.

To see it fly smoothly with no problems, and then suddenly things go haywire, tells me something is going on mid flight.

Sorry on the delays, limited time lately, but I do want to update this thread once a final conclusion is made.  I have to say i'm getting pretty solid on this same route over and over though haha

I checked and accelerated wear isnt checked.  After i had the weird hardware failure I set my clock speed back a notch on both ram and cpu (5.0 vs 5.1 and 3000 vs 3200 etc).. i also turned off all plugins i thought could be conflicting.  2 variables at once.

Had successful flights nothing weird.  Turned back on those plugins (at least the ones i think are causing issues).. 1 successful flight out of 1 so far.

Ill test one more time, if all goes well I will conclude it was overclock related (though i cant say i ever recall seeing anyone having autopilot issues due to overclocking before?).

Side question, really for another thread but, with the ch pedals i still rather struggle taking off on runway moving all over the place.  I have all 6 sliders in joystick settings at 25% and often try the rudder trim to the right a tad, either way it still can be a handful, maybe thats just realistic or maybe i need to bump the % on the settings.

 

Edited March 29, 2019 by theskyisthelimit99

[vladd148]

Make sure the stability augmentation is set to 0% on the yaw. I had the same issue prior. Additionally, Set the yaw curve on your pedals so that it's a bit more fine on the small movements. Should solve it. I am able to take off without too many issues and I am using the paddles on my T16000M for rudder, so you shouldn't have any issues with the pedals once your make those changes.

[ebbsy1]

hi ive noticed on the 1st vid you posted you armed the auto pilot and nav but you did not select the vs button.you can delete the flight plan by pressing the flight plan button then the menu button you will then get a list of commands one is delete flight plan just push the fms knob then use the outer dial on the fms highlight delete flight plan then enter.i also use auto pilot to climb out some time and what i do is select the alt before take off lts say 10000 i also input the flight plan on the ground then after i take off press auto pilot click nav then i click vs then i use the vsdial at the side of the button and select the fpm i require 

Edited March 29, 2019 by ebbsy1

[ebbsy1]

sorry just seen the 2nd vid dont know whats going on there.do you use a saitek multi panel for auto pilot as i have 1 and it can mess up on certain payware aircraft

[theskyisthelimit99]

22 hours ago, vladd148 said:

Make sure the stability augmentation is set to 0% on the yaw. I had the same issue prior. Additionally, Set the yaw curve on your pedals so that it's a bit more fine on the small movements. Should solve it. I am able to take off without too many issues and I am using the paddles on my T16000M for rudder, so you shouldn't have any issues with the pedals once your make those changes.

Thanks.. Any ideas on how to adjust the response curve as you mentioned, not sure if i should increase the curve at certain parts or how to adjust.  Ill try the 0%, do you have the rest of the settings set to any certain values

[theskyisthelimit99]

4 hours ago, ebbsy1 said:

sorry just seen the 2nd vid dont know whats going on there.do you use a saitek multi panel for auto pilot as i have 1 and it can mess up on certain payware aircraft

No, i dont have a saitek panel anymore, i used to before VR, though all these tests are just 2D.

I still think the large issue was my overclock (somehow causing this), but maybe not, need a few more tries.

[theskyisthelimit99]

In this test i missed the magenta line or didnt intercept it correctly i think, unsure.. If its not locking on, do you just aim the aircraft at any part of the fpl lines and it should lock on?  In this case it just kept going and yeah i tried a hard turn at too high of a speed and couldnt pull up in this fast test.  First one in a while i've had that ended in misery, though i dont think quite the same as previous.

 

[Hoekstes]

I had this same problem and realised I was trimmed almost completely nose down before engaging the autopilot.  Looking at your screen, you're trimmed almost completely nose down as well.  Centre your yoke pitch and trim the plane before engaging autopilot.

[ebbsy1]

12 hours ago, theskyisthelimit99 said:

No, i dont have a saitek panel anymore, i used to before VR, though all these tests are just 2D.

I still think the large issue was my overclock (somehow causing this), but maybe not, need a few more tries.

have you tried just flying with mouse and keyboard and just using the tbm ap controls or flying another plane just to make sure it not hardware related  .i had a go on my to try replicate what was happening when i got to alt and leveled off everything was ok and following  the magenta line, then i nudge my trim wheal on the saitek panel soon as i touch that all ap went off and it started to pitch up just like yours.