New regulations enacted for meteorological evaluation towers

Gov. Rick Snyder signed into law on March 1 Public Act 28 of 2016 that regulates meteorological evaluation towers (MET). Usually less than 200 feet high and erected quickly, these towers are used to evaluate locations for electricity-generating wind turbines. The new law comes after a recommendation from the National Transportation Safety Board (NTSB) requesting states to enact MET regulations and register their locations in a directory.

“We are very pleased the governor and Legislature passed this law quickly,” Mike Trout, Michigan Aeronautics Commission director, said. “An MET can be very problematic for agricultural, balloon, and helicopter pilots to see, and could cause a crash.”

Effective May 30, 2016, the law requires tower owners to register towers that are 50 feet or higher with the Michigan Department of Transportation (MDOT) Office of Aeronautics. Tower locations will be recorded in MDOT’s database of tall structures. Requirements for the towers include :

Painted in equal, alternating bands of orange and white, with orange at the top of the tower and ending with orange at the bottom of the tower.

Attach at least one orange marker ball to the highest point on each guy wire.

Place one or more 7-foot safety sleeves at each anchor point on each guy wire.

For information on applying for a Michigan tall structures permit, please visit the Office of Aeronautics website at, contact Hilary Vanderstow at, or call 517-335-9418.

The University of Nebraska-Lincoln has a helpful YouTube video that illustrates the issues with unmarked METs and examples of marking the towers: