Orange balls float on power lines as safety markers. Under Federal Aviation Administration guidelines, these orange balls, commonly called aviation balls, make power lines highly visible to helicopters, low-flying planes, gliders and other aircraft.
Aviation balls mark hanging wires, such as power lines or suspension cables. The spherical markers vary in color and size.
According to FAA guidelines, aviation balls should be clearly visible to approaching aircraft from at least 4,000 feet.
Markers are solid colors in aviation orange, white or yellow. The aviation balls are evenly spaced along wires to highlight the cable profile.
Spheres or cylinders 36 inches in diameter mark long cables over water features, such as rivers and lakes. Smaller spheres 20 inches in diameter mark power lines less than 50 feet above the ground.
Aviation balls protect wildlife as well as aircraft from wire strikes. The Department of Transportation reports that aviation balls placed on power lines keep migrating birds from hitting the lines as the birds approach wetlands.
