First, when on an easterly or westerly heading and the aircraft accelerates, the center of gravity of the bowl lags behind the pivot, making it tilt forwards. Because of magnetic dip the compass will show a false turn towards the north if in the northern hemisphere or vice versa a false turn towards the south if in the southern hemisphere. Also if the aircraft is decelerated the compass will show a false turn towards the south in the northern hemisphere and false turn towards the north in the southern hemisphere. The error is neutralized when the aircraft has reached its velocity and the magnetic compass will then read the proper heading. Pilots in the northern hemisphere remember this by the acronym "ANDS"; accelerate north, decelerate south. The opposite occurs when flying in the southern hemisphere. This error is eliminated while accelerating or decelerating on a heading of exactly North or exactly South.