RE: Viper 500 plane issues
Make the tail even with the wing... period. It will never track correctly otherwise. You need more lift so either set the tail with a 1 degree incidence that will create lift or shim the wing to raise the leading edge as previously so well described to create the needed lift so it will fly level with no up elevator trim. One thing you will notice about this wing is that it will seem to glide almost forever when landing so manage your speed in a consistent manner during your landing approach. You get this plane setup right and you will be amazed at how well a $119 dollar ARF racer can fly! It is no $500 composite, but, it is competitive or can flat out whip one heck of a lot of the kits and ARFs used over the last 25 years with a good pilot. Good luck.