John, while you are flying paralell to the runway in either direction the inside wing is low. When you pull vertical it is going the direction of the low wing. It's kind of an optical illusion thing. Try flying directly away from yourself so you can see that the wings are level and see what it does. You will need a little right rudder as you round the corner to the vert but ease off once vertical and it should go true for about 100 ft. If not then adjust thrust angle accordingly.