So, this is not my first run-in with this issue and I'm out of ideas on how to eliminate it. During most flights with the 777 I configure the aircraft while at a gate, setting all criteria including CoG. Usually while taxiing or on the runway I'll see the pitch trim lever spike to full nose down. Sometimes I can click the lever back to centered and it will remain, sometimes I literally need to fight with it until it stays centered. Frequently this occurs during my TO run, causing the MFD warnings and spoiling the experience.

I have:

Purged any custom configurations, panel states, etc

Deleted the trim axis from my flight controller setup for ALL aircraft (in the sim general settings)

Removed elevator trim from FSUIPC, as well as creating an aircraft specific profile that disables elevator trim axes.

 

My trim lever still jumps on its own. Typically during cruise I will see this again, as evidenced by porpoising during cruise.

What I cannot figure is what is sending these signals to the sim; I experienced this both in my FSX installation and now in P3dv4.1, so I am convinced it's not the 777 but something on my pc or hardware. 

I'm open to any and all suggestions 

Did you try disconnecting your controls and flying with the keyboard to see if your controls may be causing the issue?

Agree with Kevin, something is creating the trim nose up/down signal.  Double check also the key command assignments in P3D to verify only the default commands exist.

Also, I am a little worried when you say "trim lever" in the 777.  One does not normally use the trim levers, only in abnormal conditions, otherwise all trim inputs are with the yoke trim buttons.

In addition to this I have seen other things interacting with the airplane:

first as you use fsuipc: the safest way to get rid of all unwanted settings (happens easily if you forget to click aircraft specific) is to remove the fsuipc.ini from the modules folder. It will rebuild a default file. 

Second: by any chance, do you use VOX ATC or other programs that use to interact with your autopilot or airplane „simulating“ a first officer?

Third: As Kevin and Dan have pointed out, check your controllers. P3D and FSX both use to assign all kinds of controls to every controller they can find. Also to virtual mouse axes and so on.. go through aaaall the controllers set in the P3D options. There are some you might don‘t even know to have :D

 

good luck :)

Thanks all for the replies, been slammed at work so didn't have a chance to test further (and yes, it's the hands-off-don't-touch-that trim lever on the pedestal that's moving on its own  ). My controller command is mapped (or was before I deleted it for testing) to the yoke trim switches that move appropriately when used, rarely.

I've been able to review/confirm/eliminate assignments that might be causing this and had some limited success flying without my trim level spiking, but still occurs occasionally. It's odd that it seems only to occur at certain phases of flight, but of course those are the phases where the controller is being manipulated most.

Seems likely to me that my venerable old Saitek setup may be soon for retirement; I've gotten MANY years out of it but the erroneous inputs are now IMO the only reliable possibility. 

Edited April 13, 20188 yr by sddjd

I had this happen to me this morning in another aircraft with the gear lever. It was just bouncing around like it was having a seizure. I unplugged my controller and then plugged it back in. That fixed it.

Ted Striker