Harvesting Safety in the Skies
Navigating Risks in Agricultural Aviation
By Tom Hoffmann, FAA Safety Briefing Magazine
It all started with a particularly nasty caterpillar infestation at a catalpa tree grove four miles outside of Troy, Ohio. Shortly after noon on Aug. 3, 1921, Army 1st Lt. John A. Macready made history when he departed in a Curtiss JN-6 “Jenny” outfitted with a 32-gallon hopper designed to dispense powdered lead arsenate and hopefully protect the besieged trees from further damage. Spreading 175 pounds of the insecticide during six low-altitude passes over the grove, Macready was successful in eradicating the greedy grubs that were quickly decimating a prime source of timber for posts and poles. It was estimated that 99% of the catalpa sphinx caterpillars were destroyed after the operation. With that flight, the agricultural aviation industry was born.
Fast-forward more than 100 years, and agricultural aviation has grown leaps and bounds to include more rugged, powerful, and purpose-built aircraft with payloads that far eclipse those of the early crop dusters. The largest of these boasts a 1,200-horsepower turbine engine and nearly 10,000 pounds of payload. The agricultural aviation industry has also grown to include helicopters, and more recently, an expanding array of unmanned aircraft systems (UAS), or drones. As of June 2025, there were more than 3,400 certificated part 137 operators (both crewed and unmanned).
Providing aerial application of crop protection products has proven to be an invaluable tool for farmers in all 50 states. According to the National Agricultural Aviation Association (NAAA), aerial applicators treat 127 million acres of cropland annually, an estimated 28% of cropland in current production. The NAAA also estimates that an area the size of Tennessee would be needed to replace the yield lost if aerial application were not available for five commonly treated crops in the U.S. This greater crop yield results in less land needed for farming and, in turn, preserves more wetland and forest ecosystems.
High Stakes at Low Altitudes
While there are many clear benefits of using aircraft to treat crops, agricultural aircraft operations do present a multitude of risk factors for pilots. These pilots operate in a low-altitude environment with multiple terrain and obstruction hazards, deal with the complexities and nuances of loading and dispensing chemicals, and face the reality of fatigue from working 13-plus hour shifts. That’s on top of having to deal with weather and wind constraints, the potential for mechanical difficulties, the constant monitoring of land boundaries and GPS data, the cumulative effects of noise and vibration, dehydration — the list goes on.
In fiscal year 2024, there were 15 fatal accidents involving agricultural operations. Prior to that, the fatal accident rate has remained stubbornly consistent at 11 accidents in the previous four years. However, there are efforts by the FAA and industry to try to correct that trend by providing pilots with better educational resources and instilling safer practices. Let’s take a closer look at some of these resources and how they can help you better navigate the challenges of aerial application.
Agricultural pilots should survey and perform a thorough reconnaissance of the area to be treated prior to flight, even if it’s a field they’re familiar with.
Sowing the Seeds for Safety
A good starting point for safety is with the regulations. Agricultural aircraft operations are covered under 14 CFR part 137, which defines it as the operation of an aircraft for the purpose of (1) dispensing any economic poison, (2) dispensing any other substance intended for plant nourishment, soil treatment, propagation of plant life, or pest control, or (3) engaging in dispensing activities directly affecting agriculture, horticulture, or forest preservation, but not including the dispensing of live insects.
Subpart B of this rule covers the certification requirements for obtaining an agricultural aircraft operating certificate, while subpart C covers the operating rules. Agricultural pilots must have a commercial certificate to work for hire and meet the requirements of part 137. That includes demonstrating to the operating certificate holder that they meet the knowledge and skill requirements prescribed in section 137.19 (e). In general, this ensures the pilot is familiar with safe handling of the economic poisons used, the aircraft’s performance capabilities, and how to safely execute the maneuvers required for the operation. Typically, an agricultural operator will have a chief supervisor who, once they pass the FAA’s knowledge and skills test, is issued an endorsement to supervise agricultural operations. The chief supervisor can also administer the knowledge and skills tests for pilots hired under that certificate. For more information on the test, see the NAAA’s Agricultural Airman Guidelines.
Keep in mind that while part 137 does offer some relief from part 91 to perform these specialized operations, part 91 still provides governing authority. For example, section 137.49 authorizes pilots to perform maneuvers below 500 feet above the surface that are necessary for the operation and that do not cause undue hazard to persons or property. However, 14 CFR section 91.303 restricts all pilots from performing aerobatic maneuvers below 1,500 feet (i.e., banks greater than or equal to 60 degrees, or nose up/down attitudes greater than or equal to 30 degrees relative to the horizon). Additionally, an agricultural aircraft pilot should pay particular attention to section 91.103 (Preflight Action), which requires them to be familiar with all available information concerning that flight. That includes everything from assessing runway lengths and weight and balance calculations to reviewing airspace restrictions and weather conditions.
Mapping Danger
“Preparation is important,” says Charles Grabill, an aviation safety inspector and part 137 subject matter expert with the FAA’s General Aviation and Commercial Division. Grabill suggests agricultural pilots survey and perform a thorough reconnaissance of the area to be treated prior to flight, even if it’s a field they’re familiar with. “Look carefully at the environment for obstructions like towers, power lines, wind turbines, or any uncharted obstacles.” This may involve both aerial and ground surveys.
Grabill recalls one accident investigation where an ag operator flying a rotorcraft saw and struck a wire he assumed was going in a different direction from a pole. The pilot involved in the accident survived but stated that if he had just made another pass and studied where that wire went from the pole, he would have been able to avoid it.
To supplement your situational awareness before flight, have a look at these resources:
- FAA SAFO 10015, Flying in the Wire Environment
- NTSB Safety Alert 35, Preventing Obstacle Collision Accidents in Agricultural Aviation (PDF)
- NTSB Safety Alert 16, The Hazards of Unmarked Towers (PDF)
Another excellent reference for shoring up safety practices and risk mitigation strategies is FAA Advisory Circular (AC) 137–1B on agricultural aviation operations. One key pointer in the AC is to exercise caution when flying over sloping terrain: Flying up the slope may result in stalling the aircraft before reaching the end of the swath run or contribute to an inadvertent stall during the pullup or turnaround.
The AC also mentions the helpfulness of using a flight risk assessment tool (FRAT) during your preflight prep. Echoing the importance of this tool, NAAA recently released a FRAT (PDF) specific to the agricultural aviation industry. The 24-question FRAT breaks down questions to be considered annually, monthly, daily, and before each flight. Answering “no” to any of the questions should be a hard stop for a pilot to either reconsider the flight or find ways to mitigate the risks identified.
Focus on Fatigue, Please
While fatigue is covered on the FRAT, it is a risk to the agricultural aviation industry that should be heeded with added attention. Beyond the accident risk factors mentioned earlier, agricultural pilots must also contend with having a finite “spray season” when almost all dispensing operations occur. This is typically June to August in the North and April to August in the South. These short windows of time to work in often mean long, grueling days. A 2019 survey conducted by NAAA reported that more than half of agricultural operators (55%) work 8 to 12 hours per day during the application season, with more than a third (35%) averaging 13 to 16 hours per day.
NAAA’s new 24-quesiton FRAT breaks down questions to be considered annually, monthly, daily, and before each flight.
Given the focus on fatigue, it’s no surprise that the subject is front and center within many industry/government educational materials and reports, such as:
- NAAA’s brochure on combating fatigue (PDF)
- Fly Safe messages developed by NAAA’s Professional Aerial Applicators’ Support System (PAASS)
- NTSB special investigative report (SIR) 14/01 on the safety of agricultural aircraft operations. The report advocates for guidance that could “help operators and pilots develop effective strategies to reduce the likelihood of fatigue, dehydration, hunger, and other physiological factors that can negatively affect a pilot’s concentration, decision-making, and performance.”
- FAA Safety Alert for Operators (SAFO) 20004 on agricultural aviation safety. The SAFO reinforces the importance of proper rest to combat fatigue and encourages agricultural pilots to establish a regular routine of uninterrupted sleep and to take breaks or 30-minute naps, if possible.
- FAA AC 120–100, Basics of Aviation Fatigue
High-Tech Harvesting
With a recently streamlined certification process in place, the use of drones in the agricultural aviation industry has grown significantly. In fact, the number of unmanned part 137 operating certificates as of June 2025 is at 1,710, nearly equal to the number of crewed operators at 1,750. “This rapid growth has improved accessibility to aerial application services across a wider geographic and economic spectrum, providing more flexible and timely solutions for growers of all sizes,” says Ryan Smith, an aviation safety inspector with the FAA’s Emerging Technologies Division. This versatility makes drone use particularly beneficial for small-scale farmers and niche markets that previously couldn’t justify or afford manned aerial services.
Drones also offer some unique operational advantages, like performing precision spot treatments in sensitive or hard-to-reach areas, accessing narrow waterways, and navigating steep or technically challenging terrain that would be unsafe or impractical for manned aircraft. “These capabilities open the door to targeted applications, such as invasive species control and selective weed management in areas that were previously underserved or unreachable,” adds Smith.
Agricultural pilots must stand committed to a culture that encourages continued learning and promotes safety above all else.
Agricultural drones have had a stellar safety record with no fatalities or serious injuries reported to date. That’s due in part to the FAA’s robust authorization process and the conditions and limitations set forth in the operator’s letter of exemption. These specific conditions and limitations (e.g., safe operating distances, weight limitations, flight planning requirements, lost link procedures, etc.) provide mitigations to maintain safety for operators, persons, property, and other aircraft. They also form the basis of the operations and training manual that all part 137 drone operators are required to have and comply with.
You Reap What You Sow
It’s clear that agricultural aviation plays a vital role in modern farming and has a positive impact on many of the products we purchase and consume. However, the numerous unique hazards that exist with this type of operation make it an inherently risky activity. While advancements in technology, such as GPS navigation, collision-avoidance systems, and improved aircraft design, have greatly benefited operators in this environment, these tools alone can’t guarantee safety. Agricultural pilots must also commit to a culture that encourages continued learning and promotes safety above all else. Together, these practices can establish a foundation for minimizing risk and keeping the agricultural aviation industry both prosperous and safe. That’s certainly something to make hay about.
Safety Tips for Aerial Applicators
Focus on pre-flight decisions; assess hazards during takeoff and during application (e.g., wire hazards and towers).
Become familiar with your field — do your reconnaissance prior to each application.
Consider terrain, congested areas, and the applicable plans, type, and quantity of product being applied for proper weight and balance.
Thoroughly assess the weather, including any potential changes to wind and density altitude.
Use the IMSAFE checklist and consider any human factors that could impact safety (e.g., dehydration, fatigue, noise, complacency).
Maintain constant communication with your ground crew and brief yourself as you go, even talking to yourself aloud.
Be sure your aircraft is airworthy and is in compliance with all Airworthiness Directives, Service Bulletins, and required inspections.
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Tom Hoffmann is the editor of FAA Safety Briefing. He is a commercial pilot and holds an A&P certificate.
