Abstract: Apparatus for use by the operator of an aircraft in guiding the aircraft, in areas where electric power lines are in operation. Pickup means are located at three or more locations on the aircraft and are used to detect three orthogonal components of the "near field" of the power line, the radiation field at 60 cycles per second being negligible. These components are fed through suitable computing and indicating means to direct the operator in flying the aircraft so that it approaches and then follows the power line, by displaying the angle between craft heading and power line direction, and the craft distance from the power line.