This is normal for most plane. The spin of the propeller usally causes the plane to pull to the left (when viewed from behind the plane). To counteract this many planes build some right thrust (once again, viewed from behind the plane) into the plane. Also, many planes will build in some down thrust as well. If you look at the plane from the side you may notice that the motor may be pointing slightly down. This is not set in stone and not all airplanes have these built in. But if you have them they are there to make the plane handle a little bit better and you should leave them setup that way.

Ken
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