Aerial Application Regulations and Special Local Need (SLN) Permits

Aerial Application Regulations and Special Local Need (SLN) Permits

Exam Focus: Understanding FAA Part 137 coordination, Category 11 Aerial Application certification, aerial drift dynamics, aircraft security rules, and special registration mechanisms under FIFRA Section 24(c) (SLN) and Section 18 Emergency Exemptions is essential for high scores on the Florida exam.

Aerial pesticide application allows rapid treatment of vast agricultural acreage, forestry tracts, and aquatic sites. However, due to high speed, flight elevation, and potential for off-target drift, aerial operations are subject to intense federal and state regulatory scrutiny. Additionally, special regulatory mechanisms permit Florida to issue custom product registrations during local pest emergencies.

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Dual Jurisdiction: FAA Part 137 and FDACS Category 11

Aerial pesticide application in Florida operates under dual federal and state jurisdiction:

1. Federal Aviation Administration (FAA) - 14 CFR Part 137:

   • Regulates Agricultural Aircraft Operations.
   • Governs pilot flight qualifications, agricultural aircraft airworthiness certificates, low-level flight waivers, and congested area flight permits.
   • Mandates that agricultural pilots hold a valid FAA Commercial Pilot Certificate and Part 137 Agricultural Aircraft Operator Certificate.

2. FDACS - Chapter 487 Category 11 (Aerial Application):

   • Regulates the chemical application aspect of aerial operations.
   • Mandates that any pilot applying pesticides by fixed-wing airplane or rotary-wing helicopter in Florida must pass the General Standards (Core) exam and the Category 11 Aerial Application exam (min 70% passing score).

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Aerial Application Spray Physics, Calibration, and Drift Mitigation

Off-target movement (drift) is the single greatest liability facing aerial applicators. Understanding spray droplet physics and atmospheric factors is critical.

Droplet Size Dynamics and Volume Median Diameter (VMD)

• Volume Median Diameter (VMD): Represents droplet size spectrum. Small droplets (<200 microns) remain suspended in air currents for extended periods, creating severe drift hazards.
• Nozzle Configuration: Nozzle orifice size, spray angle, and orientation relative to the aircraft slipstream control droplet size. Orienting nozzles straight back (0 degrees) produces larger droplets; angling nozzles forward into the slipstream shears droplets into fine, drift-prone sprays.

Boom Length and Wingtip Vortex Entrainment

To prevent wingtip vortices (fixed-wing) or rotor downwash vortices (helicopters) from trapping fine spray droplets and lifting them high into air currents:

• Fixed-Wing Aircraft: Maximum boom length must not exceed 75% of the total wingspan.
• Rotary-Wing Aircraft (Helicopters): Maximum boom length must not exceed 85% of the rotor diameter.

Fixed-Wing Wingtip Vortex Trapping Prevention:
|<------------------------------ Total Wingspan ------------------------------>|
|=====[=================== Maximum Boom Length (75%) ===================]=====|

Thermal Inversions and Wind Boundaries

• Ideal Wind Window: Apply when surface winds are between 3 mph and 10 mph blowing away from sensitive non-target areas.
• Thermal Inversions: Extremely calm conditions (<3 mph) during early morning or late evening often signal a thermal inversion, where warm air caps cool surface air. Small spray droplets become trapped in the stagnant cool layer and float laterally for miles off-target. Aerial applications are strictly prohibited during thermal inversions.

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Agricultural Aircraft and Facility Security Regulations

Under Florida Statute 487.0437 and Rule Chapter 5E-9 F.A.C. (enacted following post-9/11 security mandates), aerial applicators must adhere to strict security protocols:

• Aircraft Physical Security: When agricultural aircraft are unattended, pilots/operators must secure aircraft controls using locking devices (e.g., propeller locks, control column locks, or locked hangars) to prevent unauthorized operation.
• Chemical & Mix/Load Security: Bulk pesticide storage tanks, mix/load pads, and aviation fuel storage facilities must be locked and secured.
• Suspicious Activity Reporting: Aerial applicators are required by law to report suspicious inquiries, unauthorized individuals near aircraft, or stolen chemical inventory immediately to FDACS and local law enforcement authorities.

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FIFRA Section 24(c) Special Local Need (SLN) Registrations

Under FIFRA Section 24(c), states possess statutory authority to issue Special Local Need (SLN) registrations for existing EPA-registered pesticides to address regional agricultural or environmental pest problems within state borders.

  [Special Regional Pest Problem Arises in Florida (e.g., Citrus Canker)]
                                  |
                                  v
  [Manufacturer / Commodity Group Petitions FDACS for Section 24c SLN]
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                                  v
  [FDACS Evaluates Efficacy, Residue & Environmental Safety Data]
                                  |
                                  v
  [FDACS Issues Supplemental 24c SLN Registration (Valid in FL Only)]
                                  |
                                  v
  [Submitted to EPA within 90 Days for Federal Concurrence]
                                  |
                                  v
  [Applicator MUST Possess Supplemental 24c Label During Application]

Key Requirements of Section 24(c) SLNs

• Purpose: Authorizes additional application sites, higher dosage rates, modified application methods, or new target pests not listed on the national EPA label.
• Supplemental Labeling: The applicator must possess a physical or digital copy of the approved 24(c) SLN label at the application site at the time of application. Applying under an SLN without the supplemental label in hand is a statutory violation.
• Duration: SLN registrations are state-specific and typically valid for a specified term (up to 5 years).

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FIFRA Section 18 Emergency Exemptions

Under FIFRA Section 18, the U.S. EPA may exempt a federal or state agency (such as FDACS) from provisions of FIFRA to allow the unregistered use of a pesticide during an unforeseen emergency pest situation.

Primary Section 18 Exemption Categories

1. Specific Exemption: Issued when an unexpected pest outbreak occurs, no registered pesticides are available, and significant economic loss will result without treatment. (Valid for max 1 year).
2. Quarantine Exemption: Issued to control or eradicate invasive non-indigenous quarantine pests.
3. Public Health Exemption: Granted during public health emergencies (e.g., vector-borne virus outbreaks like Zika or Eastern Equine Encephalitis).
4. Crisis Exemption: Declared directly by FDACS in urgent situations where immediate action is required before formal EPA review can occur. Valid for a maximum of 15 calendar days unless a formal Specific Exemption petition is submitted to EPA.

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Section 25(b) Minimum Risk Pesticides

Pesticides containing active ingredients listed on EPA's 25(b) list (e.g., peppermint oil, clove oil, garlic extract) and inert ingredients on List 4A are exempt from federal FIFRA registration.

Florida Regulatory Mandate: Although Section 25(b) products are exempt from federal EPA registration, Florida law requires all 25(b) minimum risk pesticides to be registered annually with FDACS before they can be legally distributed or sold within the state of Florida.

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Comprehensive Florida Scenario: Emergency Aerial SLN Application

An invasive fungal pathogen threatens commercial sweet corn acreage in Palm Beach County. No federally registered fungicides effectively control the pathogen. The Florida Sweet Corn Council petitions FDACS for a FIFRA Section 24(c) Special Local Need (SLN) registration to allow aerial application of an existing fungicide at a modified rate.

FDACS approves the Section 24(c) SLN registration and submits notification to EPA. A commercial aerial applicator holding a Category 11 Aerial Application license is hired to spray the corn fields. Before taking off in an Ag-Cat fixed-wing aircraft:

1. The pilot verifies surface winds are 6 mph (no thermal inversion) and that the spray boom does not exceed 75% of the total wingspan.
2. The pilot ensures a physical copy of the approved Section 24(c) SLN supplemental label is secured inside the cockpit.
3. Upon returning to the airfield, the pilot locks the aircraft ignition controls and secures the mix/load site pursuant to Florida agricultural security laws.

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Key Takeaways Summary

• Aerial applicators must comply with FAA Part 137 flight rules and hold FDACS Category 11 certification.
• Fixed-wing spray booms must not exceed 75% of wingspan; rotary-wing booms must not exceed 85% of rotor diameter.
• Aerial applications are strictly prohibited during thermal inversions (<3 mph calm winds).
• Florida law (F.S. 487.0437) mandates securing agricultural aircraft and mix/load facilities.
• Section 24(c) SLNs allow state-specific product uses; applicators must possess the 24(c) supplemental label during application.
• Section 18 Exemptions address emergency pest outbreaks; Section 25(b) minimum risk products must still be registered with FDACS.