<span style="font-size: larger;"><span style="font-family: Comic Sans MS;">I don't get why you need to measure it at the wing tip and then take it to the root of the wing to find there is a difference? The Edge 540 has a straight leading edge, so it should be the same. What does manul say to measure it from? For small planes its always at the root, only on the big planes is it sometimes measured at the wing tip. I hope I am reading you right ...</span></span>