While the Federal Aviation Administration (FAA) requires all structures exceeding 200 feet above ground level (AGL) to be marked with tower lights or tower paint, the rules vary for structures below that height. Unmarked towers are extremely difficult for aerial applicators to see as they conduct their work at speeds up to 160 mph just 10 feet off the ground, and accidents (too many, fatal) occur every year as a result. All Meteorological Evaluation Towers (METs) between 50 and 200 feet in rural areas with an above ground base of less than 10 feet in diameter must be both properly marked and logged into a designated FAA database. Well-funded lobbying from the telecommunications industry loosened the requirements for all other towers (cellular, TV, radio, RTK, etc.) meeting these same specifications to only need marked or logged. Though congressionally mandated in the 2018 FAA Reauthorization, the FAA has yet to follow through with generating this database. NAAA maintains that all towers should be marked and logged. Alongside its state association partners, NAAA will continue to push to make towers more visible for low-altitude pilots and to develop policies that consider aviation safety. 

NAAA, state agricultural aviation associations and their memberships have been advocating for obstruction marking, including towers and their associated guy wires for decades. The telecommunications industry’s densification of its tower networks (driven by higher bandwidth, shorter range frequencies) continues to increase risk to aerial application operations.

Here are some communications on this topic from the last several years:

Tired of towers being erected in your area without any type of notification to fight back?  Using the FAA’s Obstruction Evaluation / Airport Airspace Analysis (OE/AAA) website, users can now be notified when a structure is proposed in an area that might impact operations allowing you to petition the local zoning authority to build the tower(s) elsewhere or mark it to ensure it will be easily visualized for low-flying aviators.

To receive these notifications, simply complete the following steps:

Once your account is created:

  • Under “My Account and Email Notifications” click “Subscription Preferences”
  • Add a new subscription, and set a radius of your choosing from your home airport

You will then be notified anytime the FAA’s OE/AAA conducts a study for a proposed obstacle in that area. You can then work with your city or county governments and the entity constructing the obstacle to ensure it doesn’t affect your operations.

While no national database of low level towers has been constructed just yet per federal legislation NAAA was instrumental in urging Congress to enact, there are some resources ag aviators can utilize. The FAA’s Digital Obstacle File (DOF) can provide you information about potential obstacles in your flight path before you even take off.

The FAA receives obstacle information from a variety of sources both inside and outside the FAA. The FAA then evaluates the obstacle data based on their analysis of supporting documentation and assigns an accuracy code. The DOF is updated every 56 days, but you can alternatively download the Daily DOF to get more up-to-date information.

These include many obstacles of interest to aviation users above 200 feet as well as lower obstructions mainly near airports. Structures below 200 feet not near airports are only submitted to this database voluntarily. The FAA’s Obstacle Team is working on new techniques to improve the accuracy of obstacle data accessible to the public.  The FAA is interested in learning about obstacles (include the coordinates and height if known) not in the DOF, of interest for flight safety.  If an obstacle is listed as existing in the database when that is not the case, please notify their office.

For more information, email 9-AJV-532-OBSTData-REQ@faa.gov.

The University of Nebraska Lincoln Extension program and the Nebraska Aviation Trades Association (NATA) produced this video in 2012 to highlight the importance of marking METs. The FAA/FCC has since mandated the marking of METs, however, the video still provides helpful insight into why NAAA believes that all towers should be marked and the hazard they pose to aerial applicators.

In 2014, the wrongful death action filed by the family of a California agricultural aviator was settled in the amount $6.7 million against a group of defendants representing tower manufacturing, wind energy, land-owning and farming interests for not marking or making aware the location of an unmarked meteorological evaluation tower (MET) to protect the pilot. The settlement establishes a standard of care as to the use of METs for wind prospecting in agricultural areas.

The case stems from a Jan. 10, 2011, aviation fatality whereby Northern California agricultural pilot Steve Allen struck a MET resulting in his death. The MET had been erected in April 2009. The tower was an eight-inch galvanized, unmarked, unlit structure manufactured by NRG Systems Inc. It was installed by Echelon Environmental Energy and PDC Corporation, which had been hired by Renewable Resources Group, the agent and representative of ZKS Real Estate Partners and Delta Wetland Properties, to monitor wind levels to prospect for the potential to generate wind energy around the tower’s location. At 60 meters (197 feet), the tower’s height fell just short of the 200-foot threshold whereby FAA regulations would have required it to be marked in a more visible fashion to low flying aviators. Allen had been hired by Bouldin Farming Company to spread winter wheat on one of the fields in Webb Tract Island, located in California’s Contra Costa County. The defendants were mindful that the FAA had a requirement of marking and lighting such a tower if it exceeded 200 feet. By attempting to erect a tower literally inches under 200 feet, they believed the tower was not required to be evaluated or registered with the FAA, nor compliant with the requirements that it be marked and made visible if over 200 feet. The defendants, through their insurance carriers, have contributed to settle this matter for the sum of $6.7 million.

This above is not intended for publication. NAAA requests that should any party desire to publish, distribute or quote any part that they first seek the permission of the Association.