What are the orange balls on power lines and why are they so important?

On highways, in rural areas, and near airports , orange, red, or white spheres hanging from power lines serve an essential function in aviation safety and environmental protection.

Its purpose is not decorative, but preventive: to avoid collisions with low-flying aircraft , such as rescue helicopters, agricultural planes, hot-air balloons or light aircraft.

According to the Spanish National Aviation Safety Agency (AESA) , the installation of these spherical visual signaling beacons is mandatory at strategic points defined by collision risk. The suspended cables are practically invisible from the air in low-visibility conditions, and these beacons improve their identification from a distance.

Spanish regulations, based on ICAO Annex 14 and Regulation (EU) 139/2014, establish the requirements to ensure the safety of pilots and passengers in critical areas.

According to Royal Decree 223/2008 published in the Official State Gazette (BOE) and the AESA Obstacle Signaling and Lighting Guide, the installation of spherical beacons is mandatory in areas where power lines, cables, or structures may interfere with air navigation.

This includes crossings over valleys, rivers, reservoirs, roads, mountainous areas, and near airports. Furthermore, Royal Decree 862/2009 establishes that any facility located within areas protected by aeronautical easements must have signage visible from long distances.

The diameter of the beacons ranges from 60 to 90 centimeters, with an approximate weight of 5 to 7 kilograms, allowing their installation without compromising the stability of the cables.

To ensure maximum visibility , approved aviation colors are used: orange, red, and white. The maximum distance between spheres is 60 meters, which is reduced to 30 meters in high-risk areas such as approaches to runways or frequent air routes, according to AESA specifications.

The materials used, such as high-density polyethylene or fiberglass-reinforced polyester, meet the requirements of the BOE and are designed to withstand solar radiation, wind, rain and sudden changes in temperature.