Hi Coimbra,it seems there are two unrelated issues being discussed in this thread. First, the size of the trim increments. These seem rather large, when you control trim manually, so I changed the value in the airfile to make them smaller. However, this does not affect the plane's behaviour in autoflight mode at all.The other issue here, is the plane 'bobbing' up and down, when in A/P mode. This is not a trim/airfile problem, but seems more like joystick noise (which could explain your sound problems as well). Try uninstalling and reinstalling your joystick/yoke, and check the manufacturer's website for updated drivers before you do (also look for new drivers for your on-board sound). If that doesn't fix it, enable 'control spike elimination' in FSUIPC. You'll need the registered version, or (in the case of FS2002), version 2.975 or earlier.Cheers,Gosta.http://hifi.avsim.net/activesky/images/wxrebeta.jpg

I fix the bobbing up and down by moving my trim way forward, after reaching a reasonable height... It's on the the very edge of the green band. I have my CH Yoke mixture level set to be used as the elevator trim.It seems some of us are talking across issues.1. Using trim adjustments has a big effect. I have nearly always had that issuein FS2002 and now in FS2004, it doesn't seem to have changed for me. I have been able to descrease sensitivity using the FS joystick sensitivity adjustment.2. During A/P operation translating from level flight to a climb there can be a jump in pitch. I do get this but it doesn't cause any in-flight difficulties so I am happy to wait for it to be patched.

Tried to eliminate control spike of rudder, aileron and elevator. No help ...Askinf for other solution. thankscoimbra

Did you also check 'fix control acceleration?Cheers,Gosta.http://hifi.avsim.net/activesky/images/wxrebeta.jpg

yescoimbra