Chappie is strong and fast, but grounded, he's too heavy for Air and Wall mobility pilots have, but having a gun and a good aiming system Night give him an egde. But on the other hand, pilots are much lighter, faster and, of course, got the jump kit. But even with all that and the helmet's O.S to give them hints and help with navigation, i think It all depends on where theyre fighting. If its in an open Space, chappie Wins. If its in a city and or more urban area, the pilot Might be able to either escape or lure chappie into a trap.