by Justin Hetland
Airspace Engineering Specialist WisDOT Bureau of Aeronautics
When you think about protecting airspace from tall towers and other obstructions, does the Wisconsin Department of Transportation (WisDOT) come to mind? Certainly the Federal Aviation Administration (FAA) must have a role in airspace protection, but what role does WisDOT have in protecting Wisconsin’s airspace? To understand the department’s role, we must first understand the FAA’s role.
For several years, the FAA has done studies on tall towers – issuing determinations of either ‘hazard to air navigation’ or ‘no hazard to air navigation.’ These determinations, while advisory in nature, give the proponent guidance on issues such as marking and lighting; ways to make a hazard to air navigation become a non-hazard to air navigation; and when to file a Notice To Airmen (NOTAM), if necessary.
It is important to remember that FAA airspace determinations are not building permits, approvals or denials; they are advisory only! FAA airspace determinations are designed to assist tall structure proponents and permitting authorities to better understand the safety implications of the proposed structure, and ways to ensure the structure is safely compatible with the national airspace system. The entire process is completed online at the FAA’s Obstruction Evaluation website: https://oeaaa.faa.gov/oeaaa/external/portal.jsp.
This website offers valuable information, including a ‘Notice Criteria Tool,’ which allows a proponent to self-determine whether they are required to file a study under Part 77.9 of the Code of Federal Regulations. The proponent can simply plug in a few key pieces of information – latitude and longitude, site elevation and structure height – and the Notice Criteria Tool will inform the proponent if they are required to file an airspace study with the FAA.
https://oeaaa.faa.gov/oeaaa/external/gisTools/gisAction.jsp?action=showNoNoticeRequiredToolForm.
So what role does the state have in issuing permits for tall towers?
Wisconsin Statute 114.135 lays out the rules for when a permit is required from the Bureau of Aeronautics (BOA). This power does not apply to objects that are less than 150 feet above the surface at the location of the object or to objects that are located within areas that have locally enacted height limitation zoning ordinances (HLZOs). Upon receipt of an FAA determination on a tall structure, BOA will issue permits to those towers IF they have determinations of ‘no hazard to air navigation’ and meet the requirements stated in Wisconsin Statute 114.135. It is important to remember that it is the proponent’s responsibility to know whether their proposal will meet any of the requirements stated in Wisconsin Statute 114.135, and should contact BOA for a WisDOT Tall Structure Permit Application.
Beyond state-issued permits for tall structures, height limitation zoning ordinances (HLZO) are the most effective tool to control the height and placement of towers close to public-use airports. Wisconsin Statute 114.136 Airport Approach Protection, authorizes municipalities owning airports to enforce and maintain HLZOs, controlling the height of structures within three (3) miles of their airport’s boundary. With the passage of the new state budget on July 1, 2013, a provision to loosen restrictions on cell tower placement was added. The new law makes it easier for cellular companies to place new towers in locations they would not have been able to in the past. It also makes it more difficult for local municipalities to deny the placement of a cell tower due to poor aesthetics. However, this new law does not affect already existing airport and airspace protection laws such as Wisconsin Statute 114.135 or locally enacted height limitation zoning ordinances. These laws are independent and exclusive of any other authority granted in the state statutes.
Ultimately, there are three ways to protect airspace from the federal level down to the local level, and they all rely on each other to be successful. Without HLZOs, public airports would have their airspace encroached by hazardous obstructions. Wisconsin state law requires public airports to adopt and maintain HLZOs to be eligible for state and federal airport improvement dollars. In addition, Wisconsin’s state law works with FAA obstruction studies to protect airspace outside the limits of locally enacted HLZOs.
