Evaluation of a Prototype Lighted Ball Marker for Powerline Obstructions

The purpose of this project was to evaluate a prototype lighted ball marker. The lighted ball marker is a powerline obstruction marker that is designed to illuminate when it is placed directly on a high voltage powerline. Three of these ball markers were installed on a powerline near the Federal Aviation Administration (FAA) Technical Center and were tested for conspicuity during nighttime, Visual Flight Rules (VFR) conditions. Results of the evaluation indicate that the lighted ball markers provide a pilot with adequate advance warning that a powerline obstruction is being approached. Complete and partial failures of the prototype markers under evaluation indicated that reliability problems may be anticipated unless design corrections are made to production units.

Author: Eric S. Katz