On two purchases i have discovered goofs which left un tended would lead to a crash on one the esc wires werent properly soldered to the contacts. On another the wing servo was loose, i attempted to adjust the throw on the aileron arm and the servo moved side to side. On one plane the servo arm was out of center i didnt want to use sub trim and the servo was buried under the skin. Took out a knife cut the servo out which was glued in with gobbits of of glue