The Latest Hazard? Wind Farms

The latest hazard to safe helicopter flight in the United States comes in the form of wind farms. These collections of modern-day windmills, seen as an environmentally friendly energy option to gas, coal, and nuclear powerplants, are proliferating. The U.S. Energy Dept. projects wind farms could provide 20 percent of electricty in the country by 2030, compared to 1 percent today. Each of a farm's windmills typically includes a three-bladed rotor mounted on a straight pole. Many are mounted on ridgelines to better catch the wind. One problem is that the tower, even if it is illuminated in accordance with FAA obstruction rules, doesn't identify the top of the obstruction. A rotor blade at the top of its rotation may extend 80 ft or more above the top of its mounting pole, effectively extending a ridgeline (as an obstruction) by nearly 200 ft. Another problem is that wind farms can crop up faster than obstacle databases and aeronautical charts are updated.For related news