Trim setting warning at TO

[Elio Saade 0]

Hello,

It's been two flights where a warning saying that my pitch trim setting is too high for TO (I don't know the proper wording) just after I set the throttles to flex then around 80knots the warning stops and after some seconds the aircraft pitch up without any command from me and lift off before even V1. During the flight just after I engage the autopilot some second after it disconnects alone (no warnings), and every time I reengage it, it disconnects after some seconds. I checked the pitch trim setting during TO and it is at the proper setting of UP0.7. I use the fuel planner X, I put the departure and arrival airports then choose random passenger and cargo, I check if all the values are in green and then I write down the trim setting. In FSX I load the loadsheet and in perf page I put 2/UP0.7 (or whatever setting I wrote down earlier). It worked perfectly for a year but now I don't know what's happening. Is there something I should do in the fuelplanner ? (adjust CoG or something else I never touch these settings) or is there something else I might be doing wrong ?

[Elio Saade 0]

So today I did a flight and I checked the pitch trim setting every minute before takeoff. Here is what I got :

The copilot sets the trim at the correct setting of UP0.4

During taxi the trim setting is still at UP0.4

When I got onto the runway, probably after the before takeoff checklist, the trim setting was UP17.1

 

I put the trim manually back to UP0.4 and I started rolling. The trim setting was going up alone so I put a little bit of pressure down on the stick so the plane won't pitch up by itself. At Vr I pitched up and I took off and the trim stabilized itself around the setting set for takeoff so the flight went smoothly.

 

Any idea of what is causing the pitch trim to change suddenly before and during takeoff ?

 

[Elio Saade 0]

Hello ?