RE: Viper500 Tips Before I maiden it ?
That change of trim when you flip your triple rate switch could quite possably be in your transmitter (? ) not the plane...
I encountered the same thing years ago with a Hitec Flash 5 Tx. so I sent the Tx. back and they "recalibrated" it...
Try a test while on the ground...watch for change in elevator trim as you flip the switch.