Regulations and Government
NTSB Calls for Marking Wind Evaluation Towers

After investigating three accidents in which airplanes inadvertently collided with meteorological evaluation towers (METs), resulting in four fatalities, the NTSB has recommended that the FAA require that all METs be registered, marked and lighted where feasible.

METs are temporary structures used to measure wind speed and direction during the development of wind energy generator facilities. They can be erected quickly and, depending on their location, without notice to the local aviation community.