Aviation Marker Balls

Electric power lines throughout the world are marked with aviation marker balls to make those lines more visible to pilots, thus reducing the chance of plane strikes. Prior to their use, plane strikes of powerlines were not uncommon, with several notable ones occurring in the 1940s in Arkansas. Though some sources state that aviation marker balls were in use starting in the 1950s, the later widespread popularity of the markers is credited to an incident involving Governor Winthrop Rockefeller of Arkansas.

Sometime in 1971, early in his second term, Governor Rockefeller and the head of the Arkansas Department of Aeronautics, Edward Holland, were flying back to Arkansas from a business trip. As they approached the airport in Little Rock (Pulaski County), Rockefeller was startled when he saw electric lines in the path of the plane. Rockefeller instructed Holland to find a method to make such power lines more visible. Holland searched the telephone directory in search of a company that could provide a solution. He settled on a not-so-successful Arkansas fiberglass boat manufacturing company operated by Jack Rutledge. Following Holland’s vague instructions, Rutledge’s company developed the now widespread cylindrical objects that are seen on power lines all over the world. The world’s pioneer in the manufacturer of the balls, Tana Wire Marker Company, was established by Rutledge in California, Missouri, in 1977. Rutledge died in 2009.

Since the late twentieth century, the Federal Aviation Administration (FAA) has provided the standards for the balls, which are to be placed on lines near canyons, lakes, rivers, and airports. Each ball measures up to thirty-six inches in circumference and weighs up to seventeen pounds. They are made of plastic or fiberglass, as neither of these materials conducts electricity. The color of the ball is selected to contrast best with the natural background. While orange is the most common color, white, red, yellow, and striped balls are also used. The balls are constructed in halves that are then clamped around the electric line and bolted together. Installation requires a specially trained crew.

Since the first aviation marker balls were installed, they have been credited with the prevention of many fatal plane crashes and have been described as “bright warning signs in the sky, protecting pilots, passengers and people on the ground.”

For additional information:
Amos, Rael F. “Marker Balls for Overhead Lines.” UPI, February 9, 1983. https://www.upi.com/Archives/1983/02/09/Marker-balls-for-overhead-lines/2851413614800/ (accessed September 16, 2026).

Bo, Rui. “What Are Those Orange Balls on Some Power Lines?” Popular Science, May 26, 2026. https://www.popsci.com/technology/what-are-those-orange-balls-on-some-power-lines/ (accessed September 16, 2026).

Nannestad, Chloë. “This Is Why You See Those Colored Balls Hanging on Power Lines.” Reader’s Digest, September 3, 2024. https://www.rd.com/article/what-are-the-balls-on-power-lines/ (accessed September 16, 2026).

“Obstruction Marking and Lighting.” U.S. Department of Transportation, Federal Aviation Administration. Advisory Circular 70/7460-1L, October 8, 2016. (accessed September 16, 2026).

Mike Polston
CALS Encyclopedia of Arkansas