dihedral

Most wings, especially trainer wings, are not straight along the wings span, or length. There is usually a crease in the middle, with both wing halves pointing upwards from the center crease. This is called dihedral and is used to help stabilize the aircraft’s level flight. Dihedral may also help the aircraft to regain level flight from a banked attitude. Too much dihedral can make the aircraft too stable to perform aerobatic maneuvers well. Too little means the aircraft may be neutral when level and require constant pilot attention to remain in level flight.