The FAA recently issued a revised Advisory Circular 70/7460-1L that updates guidelines for the proper way to light and mark obstructions affecting navigable airspace.
Among the changes include the requirement for the FAA to determine whether a structure that is 200 feet above ground level (AGL) or higher, or near an airport, does not pose an airspace hazard. Also included are new lighting specifications for wind turbines, new lighting and marking standards for reducing the impact on migratory bird populations, and standards for voluntary marking of meteorological evaluation towers lower than 200 feet.
» Advisory Circular AC 70/7460-1L
