An apparatus and method for estimating the angle of attack of wheels, wheelsets, trucks and railway vehicles traveling over a track employing a wayside system having a plurality of sensors, adjacent to the rails of the track, for detecting the passing of each wheels et of each truck. Each sensor communicates its moment of activation and length of activation caused by a passing wheel to a sensor monitoring unit for use in determining the angle of attack of the passing wheel, wheelset, truck and railway vehicle. The estimated angle of attack of the wheelset at different locations along the track may be used to detect a hunting wheelset, truck or railway vehicle.