Ground-breaking research from the University of Kansas is bound to catch the attention of any city or county in Kansas looking to jump on the wind-power bandwagon. As wind farms proliferate throughout the state, it appears consideration of their proximity to airports is important beyond the obvious obstacle presented by the turbines' height.
Researchers at KU's School of Engineering concluded small aircraft can be affected dramatically by the turbulence produced by wind turbines.
"We're really looking at two potential threats," said Tom Mulinazzi, professor of civil, environmental and architectural engineering. "These turbines can set up a circular vortex that can roll a plane if it gets in there. And they can increase crosswind speeds above what's expected, which can be a real danger to small aircraft, which don't typically take off and land with crosswinds stronger than about 12 miles per hour."
The KU team said the turbulence created can stretch out nearly 3 miles, depending on wind speed.
The potential danger strikes us as real. There have been many alleged nefarious outcomes attributed to wind turbines; hardly any withstand the scrutiny of peer-reviewed scientific research. The circular vortex was measured utilizing advanced aerodynamics modeling, as were rotational vortices generated by the spinning blades.
Kansas has about 140 public-use airports and many more private-use airports. There are 16 wind farms operating in Kansas today, but there are proposals for an additional 58, with some planned in close proximity to existing airports.
Researchers are hoping their findings will make their way in planning and zoning regulations in any locale considering a wind farm.
"So as state and local leaders consider these proposals for new wind farms, we're hoping to provide them with specific information they can use to create guidelines to ensure aircraft safety," Mulinazzi said. "Right now, there's really nothing on the books."
We believe there is an easier fix, particularly if this research is accepted by the Federal Aviation Administration. The KU team did point out FAA currently only evaluates vertical structures from a static perspective within an airport zone.
But federal regulations instruct the FAA to determine "the potential hazardous effect of the proposed construction on air navigation" and "identifying mitigating measures to enhance safe air navigation." There appears to be room for interpreting these words to include measurable vortices generated by wind turbines.
Already, the FAA must be notified about any proposed 200-plus-foot-tall structure within 10,000 feet of a public-use airport with runways shorter than 3,200 feet, or within 20,000 feet if the runways are longer. Cities or counties attempting to allow wind farms anywhere close to an airport already would run afoul of federal law if they didn't notify the FAA.
The KU team is to be congratulated for potentially saving lives with their research. However, it is up to the FAA to incorporate the findings into its safety inspections. Local and state officials shouldn't have to amend all existing ordinances. Still, it wouldn't hurt to be aware of what wind turbines can do.
Editorial by Patrick Lowry