NGX in uncontrollable spin when loading saved flight

[jarmstrong 0]

Hi, all -

I am having an issue when trying to load saved flights in the 737 NGX. I am using FSX:SE and have been flying the 737-800 WL Delta livery.

First off, the plane loads up and flies perfectly. I have had zero issues when starting a new flight on the ground or during a flight. I have been trying to save and reload flights in order to free up some VAS. My current process has been to start a flight with a cold and dark cockpit, get the plane running and in flight, and get to TOC. Once stabilized in cruise I would save the game (have tried both through the FSX file menu as well as using FSUIPC autosave). Then I quit FSX completely and restart. When FSX loads I click Free Flight (my default flight is still the base trike flight), and then click Load. Selecting the save, it loads up and I see the plane in the right spot in the sky and the right attitude -- however, the second the panel configuration loads, all heck breaks loose.

Once the green bar appears and I actually see the panel state restored, the plane begins violently oscillating, both side to side and up and down. Immediately the "BANK ANGLE" annunciator is going off, and the plane is all over the place. Once the countdown stops, the plane is just uncontrollable and usually results in an overstressed failure within seconds.

I've tried to hit slew once the flight loads, which does hold the plane in position...however, once the countdown is over the plane is inoperable, the engines are not started and the displays are dark.

I'm not really sure what to do at this point -- I don't know what would send the plane into such violent maneuvers -- it isn't that the engines haven't started yet and the plane has started to nose down and glide (which seems to be normal for most users loading a flight), but rather it is as if there is some crazy control input being sent to the plane. I've tried loading with my yoke and pedals disconnected to make sure they weren't sending some bad signals, but same thing. I've uninstalled/reinstalled the NGX, same result.

When I get home today I will try a few things - first, saving and loading a flight while on the ground and seeing how the plane reacts. Two, trying a different livery and seeing if that helps anything.

If anyone has any ideas for how I can get this to work I would be very appreciative. I'm happy to send logs/save files or any other info you need to help troubleshoot this.

Thank you for the help,

Jim Armstrong

[KrisJ 43]

I used to have this issue with FSUIPC autosave. it does not appear if i save via P3D menu. I also save NGX panel state at the same time which i load after i load the flight save - not sure if its needed but i do it just in case :)

[jarmstrong 0]

Thank you for the reply, Kris. Unfortunately I'm having the problem even when saving only with FSX and not FSUIPC. I'll try and manually save the panel and see if that makes any difference...

Edited to add: This gave me some more things to test...right now I use FSUIPC to control my yoke/pedals ("Enable Controllers" is turned off in FSX). I'm wondering if that could be causing the issue. I will mess around with this tonight and report back.

Edited August 17, 2017 by jarmstrong

[downscc 1,327]

I frequently saved before TOD and sometimes after TOC, quit and restarted to control VAS. I never had a problem, I always used the menu save item and I have never used FSUIPC autosave.  A few things I do before I save is first keep the time rate at x1, aircraft straight and level and on A/P and A/T and I'm at least 10 nm before a change in heading or altitude. 

Review the PMDG Introduction on the use of FSUIPC, it's best if you don't have to but if you must they have a few constraints.  However, unless your controller is knocking it out of A/P when loading there is no reason you should be losing control.

[spearmint_flyer 578]

Have you updated to the latest FSUIPC? That was what fixed my problem. 

[mcx1000 2]

I load the 737 in the default startup scenario, and when all is stable, I load the saved flight, and there is some issues, but nothing that can't be fixed in the air.

If I don't do that, things are all out of whack. 

[cannonplug 126]

I've noticed with saved flights that sometimes the panel state is saved with a hard over right aileron or rudder trim condition. When I restart one of these flights in the air, the effects are very similar to those described by Jim (OP): basically total loss of control.

The rudder trim hard over is sometimes difficult to spot because the arrow in the window will still be pointing to center until you actually rotate the knob. The hard over aileron trim is obvious because the yoke will be significantly off center when you start up. What I do in these situations when in flight is go immediately to slew mode, wait for the initialization to finish and then reset whichever trim is off. The airplane will usually come out of slew mode relatively stable after this.

For months (years even?) I've been trying to figure out under which conditions the panel state will save with either one of these hard overs. It doesn't happen every time I save. I used to think it had something to do with me accidentally not running the sim as administrator, but this is not the case. It occurs regardless. In P3D v3, I thought it was related to low VAS conditions, but now it happens in v4 as well. So no clue. For now, I'll just keep looking for a pattern and submit a ticket if I find one.

[downscc 1,327]

I've seen the hard aileron position a couple of times, but my flights number in the many dozens. I agree, don't know why.  The full aileron deflection has always been caused by full trim deflection, I don't think it can exist alone.  I've seen a few more cases of trim being just slightly off center, and that usually only impacts the flight once A/P is engaged and heading control is abnormal.  That one has happened to me in NGX and 777, and I don't know why.  In all cases there is a panel state in suspicion but I use saved panels states many more times without problem than with.  This must be part of the magic of flying.