Low-Level Towers and Ag Aviation

Unmarked, low-level obstacles have been a top concern of the aerial application industry when it comes to aviation safety. Wind energy turbines, “flying” wind turbines, meteorological evaluation towers (METs), real time kinematic (RTK) towers, and other ground-affixed obstructions are, in many instances, not marked or lit in or near agricultural areas where aerial applicators are flying.  This can result in them being difficult if not impossible to see when flying around them. Sadly, from 2008 to 2019, nine agricultural aviators were killed in tower related accidents. Wind energy towers pose the greatest safety and accessibility threats to agricultural aviators not only because of their size, but also because they are expected to become more widespread in the coming years. These towers are often clustered closely together, creating ominous obstacles for pilots. One of the easiest and most cost-effective ways for legislators to save lives is by setting safety standards for these towers by requiring they be marked, lit and their coordinates logged in a publicly accessible database.

NAAA has been aggressively tackling the unmarked, low-level tower threat (including METs) the last several years, including working through both Congress and the FAA.

Marking Efforts Through Congress— NAAA was successful in working with Congressman Sam Graves (R-MO), co-chairman of the House GA Caucus, to include legislative language in the 2016 FAA funding extension bill to require the marking of towers between 50-200 feet with an above-ground base of 10 feet or less in diameter so long as the towers are on undeveloped land, among other conditions. The bill also requires that towers be logged in a FAA database accessible to agricultural aviators.
The telecommunications industry claims to have been taken by surprise by these changes and successfully pushed to lighten their marking requirements in the 2018 FAA reauthorization. The telecommunications industry claims unmarked towers don’t pose a threat to low-level aviators and the cost of marking towers is too high, as is the risk to tower workers who would mark existing towers. At the request of Congress, NAAA worked to find a more cost-effective alternative to the marking requirements. NAAA developed an alternative that in lieu of painting, a tower could be marked by strategic placement of fluorescent ball markers and/or the installation of lights. This approach was not accepted by the telecommunications industry, so Congress developed its own compromise and the 2018 FAA Reauthorization contained language that solely requires marking or the logging into a database of non-MET towers in rural areas between 50 and 200 vertical feet and an above-ground base up to 10 feet in diameter. METs, still must be both marked and logged.

Additionally, in the summer of 2019 NAAA conducted a thorough analysis of tower -related accidents across all sectors of aviation and discovered from 2008 to 2018, there were 40 accidents and incidents from collisions with METs, communication towers, towers supporting power lines and wind turbines resulting in 36 fatalities. This includes 22 Part 137 accidents and nine part 137 fatalities. NAAA used this startling new data to encourage landowners and tower companies to properly mark their towers and will take this information to Congress as further evidence all towers need to be properly marked.

NTSB Recommendations – In addition to NAAA’s tower marking efforts, the National Transportation Safety Board (NTSB) made recommendations to the FAA in 2013 to: (1) create and maintain a publicly accessible national database for the required registration or all meteorological evaluation towers; and (2) amend 14 Code of Federal Regulations Part 77 to require all meteorological evaluation towers be registered, marked, and—where feasible—lighted. In late 2018 the NTSB issued newly revised Safety Alert SA-016 titled “The Hazards of Unmarked Towers,” urging pilots to be vigilant for unmarked meteorological evaluation towers (METs) and other unmarked towers such as GPS functionality and telecommunications towers. 

Emerging Hazards – A more recent potential hazard in some parts of the country is the erection of RTK towers for use with farm and construction equipment auto-steering that can likewise be deployed at any location in a matter of hours. The RTK towers are like METs in their difficulty to see, but usually measure only 105 feet in height and are supported with guy wires. Communication with one of the primary owners of these towers in the Upper Midwest told a representative of NAAA they did not intend to mark or light their towers because regulations did not require it. In some areas, ag operators have been reluctant to openly oppose these towers because they are desired by their farmer customers. Regardless, safety dictates the towers should be marked for maximum visibility to low level aviation.

Without sensible placement and proper marking of all types of towers and other obstacles occurring in low-level airspace in agricultural areas, farmers may be at risk of losing important aerial application services performed on their cropland. Towers erected directly in the flight path of aerial applicators’ landing strips and/or hampering the accessibility of treatable cropland could literally shut down aerial application operations. This would detrimentally affect, in some instances, the only method farmers have available to them when the time comes to apply seeds, fertilizers and crop protection chemicals, necessary to foster crop growth, let alone other services low-level aviators contribute to benefit the public. In that vein, NAAA launched the “Towers Policy” section of its website, which provides tools to educate the public on the dangers of unmarked towers to pilots of low-flying aircraft; and addresses the safety and accessibility concerns associated with wind turbines. The tools illustrate how poor tower marking and improper wind turbine siting put pilots’ lives and farmers’ livelihood at risk. NAAA has urged federal agencies that help to subsidize and promote wind energy, such as the USDA and DOE, to help in its campaign to inform the public that improper placement of wind towers may pose significant dangers to low-level aviation operations and may negatively affect agricultural production.

USDA Rural Broadband Grant Recipients- as the USDA develops financing, policy and other aspects related to rural broadband development, the conference report of the enacted legislation directs the USDA to take into account existing FAA requirements for marking towers, specifically the law requiring towers below 200 feet in rural areas be marked or logged into a database. NAAA worked to have this provision included in the report.  The report recognizes this is important “to protect the safety of aerial applicators, aerial firefighters, public health applicators, medevac units, law enforcement and other low-flying aircraft.” This is particularly important not just for rural broadband programs specified in the 2018 Farm Bill, but also for any potential infrastructure packages Congress might consider. NAAA created education materials detailing tower marking laws and best practices that USDA will distribute to recipients of loans and grants awarded by under the USDA’s Re-connect program.

While the national database of low-level towers has yet to be completed, there are some resources ag aviators can utilize. Both the Daily Digital Obstacle File (published every business day) and the Digital Obstacle File (published every eight weeks) can provide information about potential flight path obstacles before takeoff.

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 its analysis of supporting documentation and assigns an accuracy code.

These include many obstacles of interest to aviation users, including obstructions above or below 200 feet AGL, mainly near airports. Thanks in part to a new automated process, low-level obstacles can be added to this database more quickly making it a valuable resource for agricultural aviators, and as a result a backlog of 75,000 obstructions below 200 feet spread throughout the country were added in January (even if they are not in the vicinity of an airport).

However, for now all structures below 200 feet not near airports are only submitted to this database voluntarily. The tower marking requirements for communications towers under 200 feet in rural areas will make this database far more robust.

Additionally, FAA’s Obstruction Evaluation / Airport Airspace Analysis (OE/AAA) has developed a system 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. You can sign up for alerts here.

In November 2019, the FAA began using aerial applicators and NAAA staff to beta test the database that will contain towers between 50 and 200 feet in rural areas. Another meeting was held in December to get additional applicator feedback to ensure the database is a useable tool for applicators to easily incorporate into their daily work.

During the summer of 2020 NAAA was contacted by GE wind and AWEA regarding concerns they have regarding the safety of employees working on turbines while aerial applicators are operating in the area. They cite concerns about drift to workers and mention the incident in Texas were an ag plane hit a tag line injuring a worker.  The tag line incident was explained as a buzzing accident not related to the spraying of any field and could have happened with any aircraft doing a “buzz job”.  It was further explained that buzz jobs are frowned upon in our industry.  It was also explained that drift to people is a concern that is taken seriously, they were reminded that when procuring sites to set up a wind turbine, the owners and farm operators of the land are reassured that farming operations will be able to proceed unhindered by the operation of the wind energy generation site.  GE expressed interest in finding a solution agreeable to all entities but left open the possibility of taking a regulatory route to address their concerns. 

Updates since 2020 October Board Meeting:  The FAA informed NAAA at the 2019 convention that it expected an NPRM for the low-level tower marking and logging requirements to be published in April of 2020, however, as of January 2021, NAAA, in correspondence with the FAA was told that an NPRM for low level tower marking and logging requirements is still in the lineup, but is considered to be a low priority and no date for the expected NPRM has been set.

In early December of 2020 NAAA had contact with Balmoral Engineering, an Australian company that manufactures a rotating multi color wire marking device.  Preliminary discussions with their US distributer, Sicame USA,  indicated that they were willing to work together on some type of strategy to promote the use of the device with power distribution companies.  Balmoral Engineering is also researching to see if their device would work with angled wires such as tower guy wires. 


Updated February 2021.

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