# Aerial Applicator’s

Manual

A national Pesticide a pp licator certification study Guide

# Aerial Applicator’s Manual

A N a tio na l Pesticide A pp lic a tor

C ertific a tio n S tudy Guide

Written By

Patrick J. O’Connor-Marer, PhD

Published by the
National Association of State Departments
of Agriculture Research Foundationii 

### This publication was developed under

Cooperative Agreement No. X8-83235401

awarded by the U.S. Environmental Protection

Agency to the National Association of State

Departments of Agriculture Research Foundation.

EPA made comments and suggestions on the

document intended to improve the scientific

analysis and technical accuracy of the document.

However, the views expressed in this document

are those of its authors and EPA does not

endorse any products or commercial services

mentioned in this publication.a c kn o wle d g m ents iii 

## T his manual was produced thanks to the support of the National Association of State Departments of Agriculture Research Foundation and the U.S. Environmental Protection Agency, Office of Pesticide Programs. The following people generously gave their time and contributed their expertise by serving on a Technical Advisory Committee and reviewing and contributing to the manual.

Ron Cline, Central Valley Helicopters, Ellensburg, Washington Adolfo Gallo, California Department of Pesticide Regulation, Sacramento, California Paul Liemandt, Minnesota Department of Agriculture, Pesticides, St. Paul, Minnesota Drew Martin, Purdue University, West Lafayette, Indiana Glenn Martin, Helicopter Applicators Inc., Gettysburg, Pennsylvania
Scott Schertz, Schertz Aerial Service Inc., Hudson, Illinois Russell Stocker, Bob’s Flying Service, Davis, California Dennie Stokes, Stokes Flying Service, Parkin, Arkansas Dale Thomas, Thomas Helicopters, Inc., Gooding, Idaho Mike Thompson, Arkansas State Plant Board, Little Rock, Arkansas Michael Weaver, Virginia Tech, Blacksburg, Virginia Robert Wolf, Kansas State University, Manhatttan, Kansas

The following individuals served as ad hoc members of the Technical Advisory Committee and contributed valuable information and made meetings with the committee possible.

Kenneth Degg, National Agricultural Aviation Association, Hillsboro, Illinois Richard Herrett, National Association of State Deptartments of Agriculture, Washington, DC Carol Parker, U.S. Environmental Protection Agency, Washington, DC Carolyn Schroeder, U.S. Environmental Protection Agency, Washington, DC Mike Walsh, U.S. Environmental Protection Agency, Washington, DC

Several individuals and organizations generously provided photographs used in this

manual.

Dennis Gardisser, WRK of Arkansas, Lonoke, AR Tom Hoffmann, Washington State Department of Agriculture, Moses Lake, WA Glenn Martin, Helicopter Applicators Inc., Gettysburg, Pennsylvania John Mateski, Western Helicopter Services, Newberg, OR Dale Thomas, Thomas Helicopters, Inc., Gooding, Idaho Michael Weaver, Virginia Tech, Blacksburg, Virginia Robert Wolf, Kansas State University, Manhattan, Kansas California Agricultural Aircraft Association Minnesota Department of Agriculture U.S. Department of Agriculture, Agricultural Research Service, Image Library

A special thank you to the following people who provided careful reviews, helpful suggestions, and additional information.

Scott Bretthauer, University of Illinois, Urbana, Illinois Joseph Spitzmueller, Minnesota Department of Agriculture, St. Paul, Minnesota 

# A cknowledgmentsivv CO NTENTS iv 

# C ontents

a ck n owled g me n ts

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

CO N TEn ts

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

i n troductio n

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

The National Examination

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Scope of this Manual

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

How to Use this Manual

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Detailed Content Outline

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

C HAP TER 1 La ws an d R e g ul a tio n s for t h e Aeri a l

A pp lic a tor Pilot

. . . . . . . . . . . . . . . . . . . . . . . . . . 9

Requirements for Pilot Certification

. . . . . . . . . . . . . . . . . . . . . . . . 10
EPA Requirements

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

The Pesticide Label

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Review Questions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

C HAP TER 2 Op er a tio n an d A pp lic a tio n Sa fety

. . . . . . . 17

Aircraft and Pesticide Security

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Evaluating Aerial Application Operation Security

. . . . . . . . . . . . . . 18 Timely Coordination with Authorities

. . . . . . . . . . . . . . . . . . . . . . 19 Protecting People and the Environment

. . . . . . . . . . . . . . . . . . . . . 19 Employee Training

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Employee Habits

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Application Safety

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 The Equipment

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Understanding the Work Order

. . . . . . . . . . . . . . . . . . . . . . . . . . 23 Scouting the Target Site

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Understanding Pesticide Label Restrictions

. . . . . . . . . . . . . . . . . . 25 Resolving Conflicts

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Reviewing and Documenting the Application

. . . . . . . . . . . . . . . . . 27 Planning for Emergencies

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Emergency Information

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Flight Hazards

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Plans in Case of Aircraft Crash

. . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Application Equipment Malfunction

. . . . . . . . . . . . . . . . . . . . . . . 29 Ground Crew Emergencies

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Overspray, Drift, and Other Misapplication

. . . . . . . . . . . . . . . . . . 29 Spray or Dust Contacting Bystanders or Vehicles

. . . . . . . . . . . . . . . 30co ntents vi Communications

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Review Questions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

C HAP TER 3 P RE V E N TI NG P ESTICIDE DRIFT

. . . . . . . . . . . . . . 33

Factors that Contribute to Drift

. . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Classification of Droplet Size

. . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Spray Mixture Physical Properties

. . . . . . . . . . . . . . . . . . . . . . . 36 External Factors Affecting Droplet Size and Drift

. . . . . . . . . . . . . . 37 Minimizing Off-Target Drift

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Application Techniques

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Smoke Generators

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Review Questions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

C HAP TER 4 Aeri a l Pesticide D is p ers a l S ystems

. . . . . . 43

Dispersal System Requirements

. . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Equipment and Component Factors

. . . . . . . . . . . . . . . . . . . . . . 44 Liquid Dispersal System Components

. . . . . . . . . . . . . . . . . . . . . . . 44 Spray Pumps

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Pesticide Tanks and Hoppers

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Filters and Screens

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Pipes, Hoses, and Fittings

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Spray Booms

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Flow Meters, Valves, and Pressure Gauges

. . . . . . . . . . . . . . . . . . . 48

Nozzles

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Nozzle Anti-Drip Devices

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Electronics

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
GPS Systems

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Computers

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Flow Volume Controllers

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Mapping Systems

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Positioning Booms and Nozzles

. . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Nozzle Adjustments

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Pattern Testing a Spray Boom

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Spraying System Operating Pressure

. . . . . . . . . . . . . . . . . . . . . . . 57 Dry Material Spreaders

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Ram-Air Spreader

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Centrifugal Spreader

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Review Questions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

C HAP TER 5 Ca libr a ti ng Aeri a l A pp lic a tio n E qui p me n t 63 Why You Need to Calibrate Equipment

. . . . . . . . . . . . . . . . . . . . . 64 Improper Application Rate

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Equipment Calibration Methods

. . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Calibrating Liquid Sprayers

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Calculating Sprayer Flow Volume per Mile (Rotary-Wing Aircraft)

. . . 67 Calculating Sprayer Flow Volume per Mile (Fixed-Wing Aircraft)

. . . 68 Calculating Acres Treated per Minute

. . . . . . . . . . . . . . . . . . . . . . 69 Determining Gallons per Acre

. . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Determining the Amount of Pesticide to Put Into the Tank

. . . . . . . . . 70 Calculating the Area of a Rectangular or Square Application Site

. . . . 71vii co ntents Calculating the Area of a Triangular Application Site

. . . . . . . . . . . . 72 Calculating the Area of a Circular Application Site

. . . . . . . . . . . . . . 73 Calculating the Area of an Irregularly-Shaped Application Site

. . . . . . 74 Calibrating Granule Applicators

. . . . . . . . . . . . . . . . . . . . . . . . . . 75 Computing Granule Application Rate per Acre

. . . . . . . . . . . . . . . . 76

Review Questions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

C HAP TER 6 Ma ki ng an Aeri a l Pesticide A pp lic a tio n

. . 81

Ferrying

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Checking the Application Site

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 What to Watch for During an Application

. . . . . . . . . . . . . . . . . . . . 83 Monitor Changes

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Importance of Onsite Ground Crew During an Application

. . . . . . . 84

Pilot Checklist

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Ground Crew Checklist

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Application Methods

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Application Speed

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Altitude

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Obstructions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Flight Patterns

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

The Turnaround

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Applying Granules

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Factors Influencing the Aircraft

. . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Estimating Density Altitude

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Density Altitude

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Operation S.A.F.E.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Review Questions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

R e v iew Q uestio n A n swers

. . . . . . . . . . . . . . . . . . . . . . . . . . 97

A pp e n dix 1: Pesticide R e g ul a tory A g e n cy C o n t a ct

In form a tio n

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

A pp e n dix 2: F AA R equireme n ts for A g ricultur a l

Aircr a ft Op er a tors

. . . . . . . . . . . . . . . . . . . . 101

A pp e n dix 3: He a t S tress

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

A pp e n dix 4: S te p s to F ollow i n C le an i ng Up a

Pesticide Sp ill

. . . . . . . . . . . . . . . . . . . . . . . . . . 107

A pp e n dix 5: Glob a l Positio n i ng S ystems

. . . . . . . . . . . . 108

Gloss a ry

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

In dex

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117viiiintroduction 

# I ntroduct i on

A pplying pesticides by air is an important part of many agricultural pest management activities. If you are a pilot and plan to engage in this type of work, you must become proficient in making safe, legal, accurate, and effective pesticide applications from an aircraft. However, before you begin applying federal restricted-use pesti

cides for hire, you have to demonstrate your skills and knowledge through a certification process administered by a pesticide regulatory agency. Pesticide regulatory agencies within states, tribes, and territories, as well as federal departments or agencies, are responsible for certifying pilots who intend to apply restricted-use pesticides to agricultural crops from aircraft. This federally-mandated certification process applies to pilots who make applications of restricted-use pesticides

for hire and those who work for com

mercial pest control operators. State, tribal, and territorial pesticide regu

latory agencies may require certification of pilots who apply other pesticides as well. Many state pesticide regulatory agencies in the U.S. have adopted the National Aerial Pesticide Applicator

Pilot Certification Examination as their tool for pilot certification.

In addition to the National Aerial Pesticide Applicator Pilot Certification Examination, state pesticide regulatory agencies may require pilots to pass a core examination and possibly one or more category-specific examina

tions (agriculture, forest, right-of-way, aquatic, etc.) as part of their cer

tification process. Check with the pesticide regulatory agency in whose jurisdiction you will be working for complete certification requirements. (See Appendix 1 for pesticide regu

latory agency contact information). Requirements may differ from one jurisdiction to another, and you may need to participate in separate certifi

cation processes for each jurisdiction. In addition to the aerial applicator pilot certification requirements, Chapter 1 of this book covers the general stan

dards set by Federal regulations for certifying all commercial pesticide applicator pilots and aerial pest controloperators who apply federal restricteduse pesticides for hire.

1 Robert Wolf—Kansas State University2 introduction 

## Ateam of experienced pilots and business owners who are actively engaged in aerial application of pesticides participated with an examination spe

cialist to develop the National Aerial Pesticide Applicator Pilot Certification

Examination. This committee iden

tified the essential knowledge and skills each entry-level pilot applicator needs to competently, safely, and legally perform all aspects of aerial pesticide application. The committee developed a Detailed Content Outline, included on pages 3 through 7, which serves as the blueprint for all examination questions and for this study manual. Before taking the examination, review this document so you understand the scope of knowledge and skills expected of you as you apply pesticides from an aircraft. The examination tests you on this knowledge and required skills. 

### The NATIONAL E x a m ination



## T his manual focuses on how to apply pesticides properly and safely

from an aircraft. It includes all the

content found on the National Aerial Pesticide Applicator Pilot Certification

Examination and consists of the fol

lowing six chapters:

1

— Laws and Regulations for the Aerial Applicator Pilot

2 — Operation and Application Safety

3 — Preventing Pesticide Drift

4 — Aerial Pesticide Dispersal Systems

5

— Calibrating Aerial Application Equipment

6

— Making an Aerial Pesticide Application Also included in this manual is a glossary of terms, an index, and several appendices that provide additional information that may prove useful as you prepare for the examination.



### H ow to Use this M anual

Since this is a study manual, the end of each chapter has a number of review questions to help test your understanding of the information you just read. These review questions are similar to the types of questions on the actual examination so they will help you become familiar with the examination style and process. Each chapter begins with a set of objectives corresponding to certain skills and knowledge expected of you as an aerial pesticide applicator pilot. 

### sc o pe o f t h i s m anual

John Mateski—Newberg, ORintroduction 3 Read a chapter and then test your understanding of the material presented by answering the review questions. Check your answers to these questions by turning to page 97. If you miss some questions, go back and review sections of the chapter that covers that information. Repeat this process for each of the chapters. Information of special interest is orga

nized into sidebars throughout the manual. You may find this information helpful in your work as an aerial appli

cation pilot.



# D E TAIL E D C ONT E NT OUTLIN E

f o r



### L i ce n se d / C er ti f i e d Aer ial App li c ato r p ilot s

I. O PER ATION S

A. Federal and State Regulation Compliance

1. Maintain requirements for a commercial pilot’s certification for aerial application (e.g., biennial flight review, medical)

2. Comply with all FAA regulations

3. Recognize an area that may be construed as congested by the FAA

4. Plan flight patterns to avoid passes over residences, schools, communities, field workers, or animals

5. Comply with state regulations regarding aerial pesticide applications

6. Operate according to government regulations while applying good judgment during each application

7. Maintain aircraft according to generally-accepted maintenance practices

8. Tailor application plans to the job situation and locale while addressing requirements of regulatory agencies

9. Obtain the required FAA Part 137 knowledge and skills endorsement from

the business owner/operator

10. For agricultural operations, communicate with the business owner/operator and

grower:

a. regarding job scheduling, rescheduling, and special considerations to meet Worker Protection Standard regulations

b. ensuring they have proper documentation (label) regarding the application as required by the Worker Protection Standard regulations

11. Ensure proper notification is given, including required field posting, before starting an application

B. Field Operations

1. Secure aircraft so it cannot be accessed or flown by unauthorized personnel

2. Ensure:

a. ground-support crew members can implement their job responsibilitiesintroduction 4 b. the area to be treated is clear

c. unplanned conditions have not arisen at the time of an application

3. Resist pressure to apply a product that presents unacceptable risk for the pilot, aircraft, public, surrounding crops, or wildlife

4. Refuse jobs that are unsafe or illegal

5. Participate in pre-application planning sessions and in post-application debriefings

6. Document special precautions required to protect sensitive areas or situations



### II. C O MM UNI C ATION S

A. Mixer/Loader Supervision

1. Review responsibilities of the mixing-loading crew at the base and satellite

locations

2. Ensure the proper product is loaded into the aircraft for each application

3. Perform minor in-field repairs on ground-support equipment

4. React in a positive and helpful way in an emergency situation (e.g., broken loading hose)

B. Pilot and Ground Crew

1. Use radio transceivers to communicate with the ground crew

2. Communicate information on work order changes in the field directly between the customer/field men and the business owner/operator or crew leader

3. Contact appropriate personnel when uncertain about any aspect of an application

4. Practice procedures and contingency plans to ensure necessary communications are detailed, quick, and accurate

5. Develop a strategy to notify a pilot when an aircraft should not be flown because of maintenance problems



### III. A PP LI C ATION S A FE TY

A. Emergency Planning

1. Anticipate types of accidents or incidents that can happen during the course of an aerial application or loading operation

2. Devise a contingency plan for evacuating the aircraft in case of emergency

3. Review pilot and ground crew procedures for an aircraft crash

B. Pre- and Post-Flight Preparations

1. Check aircraft fuel and oil levels

2. Seek local advice regarding topography and sensitive areas when an application

will occur in an unfamiliar location

3. Review an application job order to determine whether the job can be accomplished safely and adequately with reasonable precautions and work procedures

4. Inspect flight suits, safety harnesses, and flight helmets for proper operating

condition

5. Wear a proper aviation flight helmetintroduction 5 6. Check the operation of seat restraints

7. Inspect:

a. the fire extinguisher

b. dispersal equipment (e.g., nozzles, hoses, connections) for signs of leakage and mechanical damage

8. Develop a procedure to ensure contaminates are not carried on clothes into the cockpit

9. Maintain maps and aerial photos if available and mark any obstacles, hazards, and

sensitive areas

10. Survey a field before treatment noting sensitive situations including

• field crews • domestic animals and wildlife

• traffic or individuals	 • aquatic areas

• crops in the vicinity	 • private residences

11. Check each field for in-flight hazards (e.g., towers, power lines, guy wires, irrigation pipes, and vent pipes) before each application begins

12. Report equipment deficiencies to the business owner/operator

13. Ensure known equipment deficiencies have been addressed

14. Protect employees from chemical exposure while changing nozzles and spray equipment configurations

C. Scheduling

1. Implement work schedules that provide adequate rest periods

2. Perform the most difficult and sensitive jobs when rested

3. Help the business owner/operator plan equipment overhaul activities prior to periods of high demand

D. Pesticide Label

1. Comply with label requirements and restrictions for aerial application of pesticides including:

a. spray volumes (Gallons per Acre

— GPA)

b. buffers and no-spray zones

c. weather conditions specific to wind and inversions

2. Interpret labels that do not include a reference to aerial use



### IV. DI SPERS AL E QUI PME NT

A. Selection

1. Inspect dispersal system components for proper operating condition including hopper/tank, pump, filters, pipes, and fittings

2. Select proper nozzles for desirable coverage and drift minimization

3. Describe:

a. major components of an aerial application liquid dispersal system

b. desirable features of pesticide hoppers and tanks

c. primary ways pumps are powered, and requirements for location and output capacity6 introduction d. features, advantages, and disadvantages of a fan-driven pump

e. desirable features of pipes and fittings in an aerial dispersal system

4. List primary types of spray patterns produced by hydraulic nozzles

5. Describe:

a. features of filters and screens

b. hollow cone and flat fan patterns

6. Determine the number of nozzles for required sprayer output using manufacturer’s specified nozzle flow volume chart, aircraft speed, and

swath width

B. Position

1. Describe where:

a. filters/screens should be located in the system

b. pressure gauges should be positioned

2. Ensure

a. booms and nozzles are positioned to release spray into a laminar airflow

b. nozzles are placed to compensate for uneven dispersal from uneven

airflow from:

• wing tip vortices • high or low helicopter rotor speeds

• aircraft propeller turbulence

3. Drop nozzles to either side of, or below, airflow obstructions (e.g., landing gear, oil coolers, boom hangers, pumps and swath markers) to minimize distortion of the spray pattern

4. Place nozzles:

a. in the air stream to produce the appropriate droplet size consistent with boom pressure to give acceptable performance for each job while adhering to

label restrictions

b. along the boom to produce a uniform deposition on the target when the aircraft is flown at the normal spraying airspeed and altitude

5. Check swath pattern uniformity for each nozzle configuration used for

various flows

C. Maintenance

1. Check dispersal system pressure gauge accuracy

2. Maintain appropriate dispersal system filter cleaning schedule

3. Check nozzles for excessive wear

4. Correct leaking nozzles, fittings, and diaphragms on the ground during loading by cleaning or replacing parts as often as needed

5. Keep:

a. spray system connections and fittings tight and in good repair to minimize

leaks

b. the boom suck-back valve adjusted and in working order to ensure a positive shut-off and safeguard against leaking nozzlesintroduction 7 D. Performance Measurement and Adjustment

1. Change nozzle tips and orifices as required for various flows

2. Calculate required and actual flow volumes, and actual output

3. Verify flow volume using fixed timing, open timing, known distance, or a

flow meter

4. Adjust and calibrate:

a. the aircraft dispersal system prior to use on a job

b. after any modification is made to the aircraft or dispersal system



### V. A PP LI C ATION C ON S ID ER ATION S

A. Site-Specific Meteorological Criteria

1. Recognize application limits imposed by weather

2. Determine wind velocity, direction, and air density at the job site

3. Identify climatic conditions that:

a. can affect aircraft engine power, take-off distance, and climb rate

b. promote spray droplet evaporation

4. Anticipate air temperature and humidity effects on spray droplet size

5. Describe conditions associated with:

a. thermals

b. a temperature inversion

B. Minimizing Off-Target Product Movement

1. Assess risks of off-target movement

2. Refer to USDA Agricultural Research Service spreadsheet information and nozzle manufacturer fact sheets to facilitate nozzle selection and spray droplet size

3. Select proper nozzles, operating pressure, orientation, and placement to minimize spray drift

4. Relate:

a. volume-median-diameter (VMD) and relative span to desired deposition

b. physical properties of a product to on-target deposition

5. Using a smoke generator, determine if the spray has a potential to drift

6. Evaluate vertical and horizontal smoke plumes to assess wind direction, speed,

and concentration

7. Identify positive air movement away from critical areas

8. Relate dispersal equipment configurations to airflow around the aircraft

9. Select techniques (e.g., boom shut-offs, cross-wind applications, buffer zones) that minimize product movement out of the treatment area

10. Apply product to headlands and edges of fields when drift potential is minimal

11. Document special equipment configurations or flight patterns used to reduce off-target movementintroduction 8 Glenn Martin—Gettysburg, PA C. Making the Application

1. Select a flight altitude that minimizes streaking and off-target movement

2. Choose a flight pattern that provides the best performance and safety level for job conditions and operation mode

3. Engage and disengage spray precisely when entering and exiting a predetermined swath pattern

4. Utilize swath marking tools (e.g., GPS, flags)

5. Continuously evaluate an application to ensure uniform dispersal

6. Document the product(s) applied and application conditionsLaws and Regu l ations fo r the A e r ia l A pp l icato r pi l ot 

# L aws and 

# R egu l ations fo r

the 

# A e r ia l 

# A pp l icato r 

# P i l ot

A s an aerial pesticide applicator pilot, you must abide by all regulatory requirements and restrictions that pertain to pesticide handling and aerial pesticide application. Only under an extreme emergency, where the public or environment may be in danger, can you vary from any legal flight and air

craft handling requirements. Federal, state, tribal, territorial, and sometimes local laws and regulations address the handling and application of pesticides

in the United States. These laws and regulations help:

• Provide for the proper, safe, and efficient uses of pesticides essential for the production of food and fiber and protecting public health and safety. Studying this chapter will help you to:

• Understand why you must comply with federal, state, and local regulations regarding aerial pesticide applications while using good judgment, best management, and safety practices during each
application.

• U nderstand the requirements for applying for a private or
commercial pilot certification for aerial application of pesticides and

how to maintain a valid certificate.

• K now the requirements and processes for maintaining an aircraft according to applicable regulations, safety practices, and aircraft

manufacturer guidelines and recommendations.

• T ailor aerial pesticide applications to the job situation and locale

while following the requirements of regulatory agencies.

• R ecognize congested areas and the importance of planning flight

patterns that avoid passes over residences, schools, communities,

field workers, and animals.

• C omply with label requirements and restrictions for aerial application of pesticides and interpreting labels that do not include specific use directions for aerial use.

9 

# CHAPTER 1

LEARNING OBJECTIVES10 CHAPTE R 1 • Protect the environment by pro

hibiting, regulating, or controlling certain pesticide uses.

• Assure agricultural and pest control workers of safe working conditions where pesticides are

present.

• Assure that aerial agricultural pest control is performed by qualified, competent, and responsible individuals.

• Assure users that pesticides are appropriate for the use desig

nated by the label.

• Require that pesticide and service containers are properly

labeled.

• Encourage the development and implementation of pest management systems that stress the incorporation of biological and cultural pest control tech

niques with selective pesticide uses when necessary to achieve acceptable levels of control with the least possible harm to nontarget organisms and the

environment.

Federal regulations appli

cable to the certification of people who apply pesticides and to pesticide handling and application are part of the Federal Insecticide, Fungicide, and

Rodenticide Act (FIFRA). The U.S.

Environmental Protection Agency (EPA) and state, tribal, and territorial pesticide regulatory agencies enforce

the provisions of FIFRA. EPA regu

lations focus on applicator (pilot) job knowledge including pesticide han

dling and protecting people and the environment. State licensing, use, storage, handling, and disposal regu

lations, as well as tribal, territorial, and local regulations, often further regulate application procedures and pesticide uses in order to protect people and vulnerable sensitive areas or organisms.
The U.S. Federal Aviation

Administration (FAA) certifies agricultural aircraft operations and

enforces Federal Aviation Regulations (FARS) pertaining to aircraft oper

ation. FARS Section 14, part 137 of

the Code of Federal Regulations spe

cifically addresses agricultural aircraft operations. An agricultural aircraft operation is a business that operates aircraft for the purpose of:

• Dispensing any economic poison.

• Dispensing any other substance intended for plant nourishment, soil treatment, propagation of plant life, or pest control.

• Engaging in dispensing activities directly affecting agriculture, horticulture, or forest preser

vation.

FAA regulations concern such areas as aircraft operation, aircraft inspection and maintenance, fer

rying routes, operation altitude, pilot licensing, and medical exams. Appendix 2 provides a summary of

the FAA agricultural aircraft operator certification requirements and process.



## A pplicants for aerial applicator pilot

certification must hold and maintain a commercial pilot’s license and have a

current Class II Medical Certificate. If you work as a pilot-in-command for an agricultural aircraft operator, you also

need an endorsement letter from that operator or a person designated by that operator. The aircraft you fly must be equipped with approved and properly

labeled seat belts and shoulder har

nesses for each pilot station. 

### EPA Requirements

State-administered EPA pesticide applicator certification determines the competency of individual pilots who will be applying pesticides. You must demonstrate your knowledge of general aspects of pesticide handling and appli

cation as well as your knowledge of the specialized area or areas of application where you intend to work, e.g., agri

cultural crops, forests, rights-of-way, public health pest control. 

### REQUIREMENTS FOR PILOT CERTIFICATIONLaws and Regu l ations fo r the A e r ia l A pp l icato r pi l ot Determination of Competency

State pesticide regulatory agencies

use written examinations to determine your competency in using and handling pesticides. State competency standards must, at a minimum, conform to federal regulations. To prepare for examinations testing your knowledge of general aspects of pesticide handling and application,

obtain a copy of the National Pesticide Applicator Certification Core Manual published by the National Association

of State Departments of Agriculture

Research Foundation, Washington,

DC. You can download PDF versions of manual chapters at http://www.nasda. org/StaticContent/workersafety/. The manual covers the general standards listed below. States may also have addi

tional study materials available to assist in preparing for the exam.

General Standards for All Certified Commercial Applicators

To become a certified commercial applicator, you must demonstrate practical knowledge of the principles and practices of pest control and safe pesticide use and handling. General standards of competency include the following categories.

Label and Labeling C omprehension.
You must know the format and terminology of pesticide labels and labeling, including:

• Understanding instructions, warnings, terms, symbols, and other information commonly appearing on pesticide labels.

• Recognizing product classification: “general-use” or “restricted-use.”

• Adhering to the requirement to use pesticides consistent with their

label instructions.

S afety F actors. Regulations require you to understand:

• Pesticide toxicity and hazards to people.

• Symptoms of pesticide poisoning.

• The usual pesticide exposure

routes. • Types and causes of common pes

ticide accidents.

• The precautions necessary to guard against injury to applicators

and other individuals in or near

treated areas.

• The need for and proper use of pro

tective clothing and equipment.

• First aid and other procedures to follow in case of a pesticide

accident.

• Proper identification, storage, transport, handling, mixing pro

cedures, and disposal methods for pesticides and used pesticide containers, including precautions to prevent children from having access to pesticides and pesticide

containers.

E nvironment. You must recognize how the following factors possibly

influence the environmental fate of pesticides:

• Weather and other climatic condi

tions.

• Types of terrain, soil, or other

substrate.

• Drainage patterns.

• Presence of fish, wildlife, and other non-target organisms.

P ests. For effective pest control, you need to be able to identify relevant pests and recognize the common characteristics of pest organisms and their damage symptoms and signs. You must also understand pest development and biology relevant to identification

and control.

P esticides. Your knowledge of pesticides must include:

• Knowing the general types of pesticides.

• Being familiar with various types of formulations.

• Understanding compatibility, synergism, persistence, and animal and plant toxicity of the

formulations.

11CHAPTE R 1 • Recognizing hazards and residues

associated with use.

• Being aware of factors that

influence effectiveness or lead to such problems as pesticide resis

tance.

• Knowing the proper procedures for diluting pesticide concentrates.

E quipment. You must demonstrate your familiarity with types of application and mixing equipment and know the advantages and limitations of each. You must be proficient in calibrating and maintaining pesticide application equipment.

A pplication T echniques. Regulations require you to demonstrate proper application methods for various formulations of pesticides, their solutions, and choose the correct application technique to use in a given

situation. You must demonstrate how to prevent drift and pesticide loss into

the environment.

Laws and Regulations. You must also demonstrate your knowledge of applicable state and federal laws and regulations. States may require

certification (examinations) in additional categories over and above the general standards. These additional categories align with various pesticide uses, such as agricultural pest control, rights-of-way vegetation control, vector control, or forest pest control.



## T he pesticide container label and associated labeling are important legal

documents that contain directions and restrictions you must follow when making an aerial application. Some labels refer to other documents, such as endan

gered species area protection maps or

the Worker Protection Standard provi

sions of the Code of Federal Regulations applicable to agricultural operations (40

CFR part 170). These and other docu

ments referred to on pesticide labels become part of the pesticide labeling. Some labels and associated labeling contain information specifically applicable to aerial application. Other labels and associated labeling contain information pertaining to any type of application method and do not provide specific instructions or precautions for aerial application. Certain pesticide labels prohibit the aerial application of the labeled material, so you must never apply these materials by air, even when mixed with other pesticides approved for aerial application. Labels having specific aerial appli

cation information are usually easier to interpret than those that only provide general information. Examples of 

### t h e PEST ici d e label

12 The use of 80-degree or 110-degree flat-fan nozzles is highly recommended for optimum spray coverage and canopy penetration. To

achieve uniform spray coverage, use nozzles and pressure that deliver MEDIUM spray droplets as indicated in nozzle manufacturer's catalogs and in accordance with ASAE standard S-572. Use screens that are 50 mesh or larger.

AERIAL APPLICATION

Herbicide should be applied in a minimum of 5 gallons of water per broadcast acre. Weed infestations should be treated before they

become competitive with the crop.

To achieve uniform spray coverage, use nozzles and pressure that deliver MEDIUM spray droplets as indicated in nozzle manufacturer's catalogs and in accordance with ASAE standard S-572. DO NOT use raindrop nozzles.

Aerial applications with this product should be made at a maximum height of 10 feet above the crop with low drift nozzles at a maximum pressure of 40 psi. Avoid application under conditions where uniform coverage cannot be obtained or where excessive

spray drift may occur.

Flagmen and loaders should avoid inhalation of spray mist and prolonged contact with skin.

See the SPRAY DRIFT MANAGEMENT section of this label for additional information on proper application of herbicide.

MIXING INSTRUCTIONS

Herbicide must be applied with clean and properly calibrated equipment. Prior to adding herbicide to the spray tank, ensure that

the spray tank, filters, and nozzles have been thoroughly cleaned. In-line strainers and nozzle screens should be 50 mesh or coarser.Laws and Regu l ations fo r the A e r ia l A pp l icato r pi l ot aerial-specific information covered in labels may include:

• Statements that refer to or allow aerial application.

• Specific use directions, such as for rate and dilution that apply directly to aerial applications without inter

pretation or calculations.

• Allowable weather conditions for applications.

• Restrictions pertaining to spray

volume and dilution.

• Droplet size information based on

ASABE S-572.1 (see Page 37) Spray

Nozzle Classification by Droplet Spectra.

• Drift management requirements.

• Off-target and especially sensitive area precautions.

• Buffer zone requirements.

Manufacturers must register pes

ticide products with the EPA before

anyone can buy or use them. The EPA registers specific products, not generic pesticide materials. This registration procedure protects people and the envi

ronment from ineffective or harmful chemicals. The registration procedure

includes an evaluation of each chemical

and establishes how the EPA classifies

the material at the federal level. This

evaluation determines whether the EPA classifies a pesticide as restricted-use or general-use. Only certified pesticide applicators can buy, use, or supervise the use of a federal restricted-use pesticide (RUP). States may also have specific reg

istration and labeling requirements and may restrict the use of other products not classified as restricted-use by the

EPA. Regulations set the format for pesticide labels and prescribe what information they contain. Some pes

ticide containers are too small, however, to have all this information printed on

them. In these cases, the EPA requires registrants or manufacturers to attach additional labeling. On metal and plastic containers, registrants or manufactures put such packets into plastic sleeves glued to the sides of the containers. Paper packages usually have label direc

tions inserted under the bottom flaps of the package. States or local regulatory agencies may impose additional restrictions or prohibitions on aerial applications that may or may not be included on the pesticide label. For example, local regulations may be more restrictive on requirements such as buffer areas, no-spray zones, and dilution rates. Always follow the requirements that

are most restrictive in the location where you are making an application. For example, local agencies might prohibit aerial applications regardless of label use directions, or they might prohibit fixed-wing applications under certain circumstances and require that only rotary-winged aircraft make aerial applications in these situations.



### P rofessional A erial A pplicator’s S upport S ystem ( PAASS )

A pesticide drift mitigation and education project initiated in 1996 by the National Agricultural Aviation Association (NAAA). PAASS is an industry-based collaborative educational effort that focuses on outreach to pilots and operators of aerial applicator businesses. The program’s primary goals are to reduce the number of pesticide agricultural aviation accidents, improve pilot safety, and reduce pesticide drift incidents by fostering professionally-sound decision-making. The PAASS interactive program improves critical decision-making skills sen

sitive to environmental factors. The agricultural aviation industry regards the PAASS program as the single relevant recurring training source for modern agricultural aviation pilots. Many companies providing insurance to agricultural aviators require pilots to participate in this training as a condition of insurability. Statistics show that aerial application accidents and drift incidents have notably declined since the PAASS program first began.

13CHAPTE R 1 14Laws and Regu l ations fo r the A e r ia l A pp l icato r pi l ot 15 1. Pesticide laws and regulations help to:

A

. Encourage pesticide use.

B. Protect the environment.

C

. Avoid dependence on alternative pest control

methods.

D

. Prevent pests from developing control

resistance.

2. Knowing the proper procedures for diluting pesticide concentrates is:

A

. An FAA requirement.

B. The requirement of local pesticide regulatory agencies.

C

. Part of the federal Worker Protection Standard provisions.

D

. An EPA general standard for certified applicators.

3. The format of pesticide labels is established by:

A

. Pesticide manufacturer guidelines.

B. Federal regulations

.

C

. State laws.

D

. ASABE professional standards

.

4. Knowing how to properly handle, mix, store, and dispose of pesticides is a requirement

of the:

A

. Environmental Protection Agency (EPA).

B. Occupational Safety and Health

Administration (OSHA).

C

. United States Department of Agriculture
(USDA).

D

. Federal Aviation Administration (FAA). 5. One purpose of federal pesticide regulations is to:

A

. Require public notification about pesticide applications.

B

. P rovide health benefits to agricultural workers.

C

. Establish safety standards for pesticide application equipment.

D

. Prevent agricultural workers from handling pesticides or working in pesticide-treated areas.

6. State pesticide regulatory agencies generally have the responsibility for:

A

. Certifying commercial pesticide applicators.

B. Determining the personal protective equipment required on pesticide labels.

C

. Developing material safety data sheets
(MSDS).

D

. Identifying endangered species.

7. In addition to the actual pesticide label, which of the following is part of the pesticide labeling?

A

. Any product sales brochures.

B. The job work order.

C

. Worker Protection Standard provisions.

D

. The Material Safety Data Sheet.

8. Which of the following is one of the require

ments for pesticide applicator certification?

A

. Knowing how to use appropriate application methods for various pesticide formulations.

B. Demonstrating safe aircraft operation.

C

. Following recommended aircraft inspection

and maintenance schedules.

D

. Making applications at altitudes specified in regulations. 

# CHAPTER 1: 

# L aws and 

# R egu l ations fo r the 

# A e r ia l 

# A pp l icato r 

# P i l ot Review QuestionsCHAPTE R 1 16 9. From the choices below, what pesticide use information found on a product label would be specific to an aerial application?

A

. PPE requirements.

B. ASABE droplet size requirements.

C

. Field posting requirements.

D

. Restricted-entry interval requirements. 10. Having a current Class II Medical Certificate is a requirement of the for all pilots making aerial pesticide applications.

A

. U.S. Environmental Protection Agency
(EPA).

B. State Lead Agency (SLA).

C

. Federal Aviation Agency (FAA).

D

. National Transportation Safety Board
(NTSB).

R E V IEW Q UESTION ANSWE R S ON PAGE 9717 Operati o n and A pplicati o n Safety 

# O perati o n and 

# A pplicati o n 

# S afety

S afety awareness and practices in all as-pects of an aerial pesticide appli

cation operation protects employees, the public, and the environment. Your operation needs procedures to secure the aircraft, ground equipment, and pesticide materials when not in use to prevent unauthorized access. Unauthorized access can range from individuals wanting to damage or burglarize property to crimes of opportunity, such as unplanned acts of vandalism. There is also the possibility that people are unaware of the hazards associated with a pesticide application operation while inadvertently gaining access to the facility. An example would be children who might be curious

about and attracted to aircraft or other pesticide use equipment, thereby trespassing to inspect the equipment when company personnel are not at the facility. In addition to securing the facility, you can protect people and This chapter will assist you to:

• Understand the importance of preventing security threats to the
operations and reducing hazards to the public from unauthorized or illegal access to the aircraft, pesticide materials, and equipment.

• Understand the importance of protecting people and the

environment from hazards associated with aerial application of
pesticides.

• Know steps to make pesticide applications that are safe for you and

the ground operations crew.

• Understand what precautions to take to protect sensitive areas while making pesticide applications from an aircraft

.

• Recognize the importance of good communications with the ground
operations crew and others before, during, and after making pesticide applications.

• Prepare for emergencies, including knowing proper first-aid
procedures for pesticide exposure and related illnesses or injuries,

and heat-related illnesses. 

# CHAPTER 2

LEARNING OBJECTIVES18 C H APTER 2 the environment by carefully planning each function of the application oper

ation to avoid accidents and hazards. Provide safety training to ground crew members so they know how to handle pesticides properly and work carefully

around aircraft and other associated equipment. Make sure each person involved in the application operation is well rested, alert, and not under the influence of alcohol or drugs. Develop reliable

methods of communication between you, the customers, and ground opera

tions. In case an accident or mishap should occur, take immediate steps to reduce damage and injury, including performing proper first aid and decon

tamination procedures for pesticide

exposure.



### A ircra f t an d p estici d e sec u rit y



## P rogressive and conscientious operations that handle pesticides work to actively manage risks to ensure the safety of their employees, their customers, and their communities. They focus on safely operating aircraft and mixing-loading equipment. To achieve these goals, they use preventative maintenance, up-to-date operating procedures, and well-trained staff. Because of heightened concerns about terrorism and sabotage, the oper

ation must also pay more attention to the security of aerial application equipment, facility sites, and pesticide storage areas. All aerial application operations need some measure of site security in place to minimize crime, prevent unauthorized access, and protect company assets. While many of the steps you take to ensure an effective security program seem routine, they are important to the health and safety of the aerial application operation staff and the sur

rounding community. Without effective security procedures, the business risks being vulnerable to both internal and external threats, which can pose hazards to you and the employees, sensitive business information, the facilities and equipment, and stored pesticides.



### Evaluating Aerial
Application Operation
Security

There are several important security needs and critical control points for an aerial application operation.

Securing Facilities, Storage Areas, and Surrounding Property

One of the most fundamental security needs is keeping intruders out of areas used for pesticide storage. Elements of an effective security plan can range from basic fencing, lighting, and locks, to intrusion detection systems and cameras. Inventory management policies help limit the amount of pesti

cides stored on site, reducing the risks of

accidental or intentional release or theft.

Securing Pesticide Application Aircraft, Vehicles, and Equipment

The operation you work for needs appropriate security protections to prevent intruder access to equipment used for mixing, loading, and applying pesticides. Accepted methods to prevent unauthorized flying of aircraft includeinstalling hidden electrical system shutoff switches, parking disabled trucks or other equipment in front and back of aircraft, removing batteries from air

craft, using devices that lock propellers or rotors, and disabling engines in

unused aircraft. Use similar methods to prevent intruders from operating ground vehicles, such as trucks, tractors, fork

lifts, and other motorized equipment. Always park the aircraft in a secure place when it is not in use. In addition,

establish methods to know at all times the location and status of all equipment used in the operation. Routinely update equipment records. Security awareness is particularly important for large-scale pesticide application equipment, like aircraft. The Federal Bureau of Investigations (FBI) requests that aerial operators be vigilant to any suspicious activity relative to the use, training in, or acquisition of dan

gerous pesticide chemicals or airborne application of these materials. This includes threats, unusual purchases,19 Operati o n and A pplicati o n Safety suspicious behavior by employees or customers, and unusual contacts with the public. If you observe any suspi

cious behavior, irregular circumstances, or unusual requests for information, immediately report this to a local law enforcement agency and the FBI.

Employees

Effective hiring and labor relations policies are important to obtain and retain good employees who will support and follow the operation’s safety precau

tions. The hiring process should ensure that pesticide handlers have all requisite training necessary to handle pesticides safely. Background checks of employees who will have access to secure areas, par

ticularly those areas where pesticides are stored, can be an important employee

selection tool.

Emergency Response

Effective emergency response pro

cedures help to ensure that the operation manager and employees understand how to respond and whom to contact in the case of an emergency. Aside from accidents, such plans need to consider vandalism, burglary, arson and bomb threats that target the operation, and potential widespread terrorist activity that involves the equipment or pesticides.



### Timely Coordination with

Authorities

If a breach of security or suspicious activity does occur, immediately contact the local police or sheriff’s department. The U.S. Department of Homeland Security requests that operations also report security breaches, threats, or suspicious behavior to the local FBI

field office. Information on the location

of the nearest FBI office is available at http://www.fbi.gov. Minnesota Department of Agriculture



## T he aerial application operation you work for depends on your piloting skills as well as competent ground crew members who safely and responsibly carry out their duties. Proper training and enforcing safety practices within the operation help reduce hazards to ground crew members working around equipment and aircraft. In addition, a well-developed safety program provides the structure to protect the public and nontarget areas from pesticide exposure. Providing training, assuring good employee habits, checking areas before an application, and resisting pressure to make unsafe or illegal applications are important components of the operation that protect people, areas surrounding treatment sites, and the environment.



### Employee Training

States have Occupational Safety and Health Administration (OSHA) regulations that require employers to train employees on how to safely operate equipment and avoid hazards

associated with their work. The EPA Worker Protection Standard (WPS) mandates specific training requirements for employees who handle pesticides in agricultural operations. According to this regulation, a pesticide handler in an aerial application operation is any employee who:

• Mixes, loads, transfers, or applies pesticides.

• Maintains, services, repairs, cleans, or handles equipment that may

contain residues or that has been used in pesticide mixing or appli

cation activities.

• Works with opened pesticide con

tainers, including emptied but not

rinsed containers. 

### p rotecting p eo p le an d t h e environ m ent20 C H APTER 2 • Flags during aerial applications.

The Worker Protection Standard requires that employers in agricultural operations provide training to pesticide handlers working in their operations. Employers must either provide the training themselves or arrange for someone else to provide it.

The Training Program

The WPS requires that a pesticide handler training program address the fol

lowing topics as they apply to the specific pesticide materials employees handle:

• Understanding the format and meaning of information, such as precautionary statements about human health hazards, contained in the labeling of the pesticide products. • Understanding the health hazards associated with pesticides handled by employees, including acute and chronic effects, delayed effects, and sensitization, as identified in pes

ticide product labeling.

• Knowing the routes by which pes

ticides can enter the body.

• Recognizing how exposure occurs and being familiar with signs and symptoms of exposure-related injury or illness.

• Knowing specific emergency firstaid procedures for overexposure to the pesticides that employees

handle.

• Knowing how to obtain emergency medical care when a pesticide injury

or illness occurs.

• Knowing routine and emergency decontamination procedures, including spill clean up and the need to thoroughly shower with soap and warm water after the pes

ticide handling exposure period.

• Understanding the pesticide label requirements for using personal protective equipment (PPE), recog

nizing its limitations, knowing how to use and clean it properly, and knowing how and when to repair or replace it.

• Knowing how to prevent, rec

ognize, and provide first aid for

heat-related illness.

• Understanding safety require

ments and procedures for pesticide handling, including the use of engi

neering controls (such as closed mixing systems and enclosed cabs), and proper ways to transport, store, and dispose of pesticides and properly rinsed containers.

• Recognizing how drift and runoff cause environmental damage and

hazards to wildlife.

• Understanding why it is unsafe to take pesticides or pesticide con

tainers home.

• Knowing what is required to handle pesticides safely. California Agricultural Aircraft Association

California Agricultural Aircraft Association21 Operati o n and A pplicati o n Safety • Knowing the employee’s rights, including the right:

w To personally receive infor

mation about pesticides to which he or she may be exposed.

w For his or her physician or employee representative to receive information about pesti

cides to which he or she may be exposed.

w To be protected against retal

iatory action due to the exercise of any of his or her rights.

Other Important Topics

Training must include the following general pesticide handling procedures that apply to all pesticide products:

• Understanding the importance of

wearing clean work clothing daily.

• Knowing how to properly and safely handle, open, and lift containers.

• Knowing how to properly pour pesticides out of containers.

• Knowing how to operate mixing and application equipment.

• Knowing procedures for triple rinsing containers.

• Knowing how to legally recycle or dispose of empty containers.

• Knowing how to confine spray to the target area.

• Knowing how to avoid contami

nating people, animals, waterways, and other non-target objects and

areas.

• Knowing how and where to properly and safely store containers that hold pesticides or have been emptied but not rinsed.

• Understanding and following pro

cedures to prevent unauthorized

access when containers cannot be locked up or otherwise secured.

• Understanding the importance of

washing hands thoroughly before eating, smoking, drinking, or using

the restroom. Consult with your state pesticide regulatory agency to see if there are any additional training requirements for pesticide handlers. Federal WPS regulations require pesticide handlers receive training every five years at a minimum. States may require more frequent training. Training must take place before any pesticide handling activities. Employees who are certified as pesticide appli

cators are exempt from this training requirement.



### Employee H abits

Every aerial pesticide application requires alertness and attention to detail. Before and during work periods, you and the ground crew members should never use alcohol or any drugs or medications that impair judgment or decrease mental alertness. Employees who wear personal protective equipmentmust also take steps to avoid heatrelated illnesses.

Avoiding Use of Alcohol and Drugs

A lcohol, drugs, and certain over-the-counter and prescription22 C H APTER 2 medications cause drowsiness, impair judgment, and often influence the ability to handle or apply pesticides safely. These substances may also alter the toxicity of pesticides in case of exposure. Make your physician aware of your occupation handling pesticides so that is considered when prescribing

medications. Do not use alcohol or drugs before, during, or immediately after handling pesticides, or before or during flight operations.

Staying Alert

Physical and mental alertness requires that you and the ground crew get sufficient sleep before an application operation and avoid other activities prior to the operation that cause fatigue. In addition, stress from work or personal activities distracts and interferes with alertness. Therefore, individuals experiencing high levels of stress should not participate in aerial application operations.

Preventing Dehydration and

Heat-Related Illness

Drink ing insuff icient water coupled with wearing personal pro

tective equipment during hot weather may lead to heat-related illness that may mimic certain types of pesticide poisoning. Symptoms of heat illness include tiredness, weakness, headache, sweating, nausea, dizziness, and fainting. Severe heat illness can cause a person to act confused, get angry easily, or behave strangely. Along with training on recognizing pesticide illness, WPS regulations require that pesticide handlers receive training on recognizing, avoiding, and treating heat stress. Appendix 3 describes

useful methods to avoid and treat heat

stress.



### a pp lication sa f et y



## A erial application safety processes and procedures involve the highly important components of the aircraft, the pesticide dispersal system installed on the aircraft, and ground equipment used to mix pes

ticides and load them into the aircraft. Each pesticide application you make is possibly unique for you because of differences between application site locations, obstacles, non-target areas, weather, pesticide materials, crops or target areas, and other variables. Therefore, you and the ground crew must begin by clearly understanding the work order and the pesticide label. Arrange to scout the target site and surrounding areas so you can plan the application before scheduling it. Review the pesticide label to understand appli

cation restrictions and precautions and to prepare for emergencies or other problems. Some pesticide materials may have local application restrictions such as time of use, height of application, pro

hibitions due to nearby sensitive crops, and requirements for buffer zones. Check with state or local pesticide regu

latory agencies if you need information

about additional restrictions.



### The Equipment

As a pilot, you must understand the importance of, and legal requirements for, scheduled inspections, servicing, and maintenance of the aircraft you fly. Take responsibility to assure the aircraft meets these requirements. This includes a preflight fuel and oil check, taking responsibility for proper fueling of the aircraft, and inspecting the aircraft for maintenance items each time you stop the operation for the day or for a Glenn Martin—Gettysburg, PA23 Operati o n and A pplicati o n Safety rest break. In addition, any aircraft you operate over congested areas must have had, within the preceding 100 hours of time in service, a 100-hour or annual inspection by an authorized person, or been inspected under a progressive inspection system. Congested areas include populated areas where chances of personal injury or property damage are greater if the aircraft should crash or if you must dump the pesticide load. Have the aircraft’s application equipment inspected and maintained regularly to assure that it functions properly and accurately and does not have leaks or other problems. When something malfunctions, repair it immediately. Make a daily inspection of the aircraft’s application equipment, the same as you do for the aircraft. After winter storage of the aircraft’s dispersal system, carefully inspect it for wear and leaks. Make sure all hoses are in good condition and tighten all fittings. Look for seepage around the pump housing that indicates a leaking gasket or loose

connections. Also, establish an inspection and maintenance program for ground equipment used for mixing and loading pesticide materials into the aircraft, as well as ground vehicles used to transport people, pesticides, and equipment. Keep all associated equipment in good repair. Any breakdown in this equipment will delay the pesticide application, wreak havoc with scheduling, and could be costly to the business and customers. Keep on hand spare parts and sup

plies, such as nozzles, hoses, fittings, drive belts, fuel, lubricants, and other components that are critical to the oper

ation. Replace spare parts and supplies used during a breakdown so you always are ready for future operations.



### U nderstanding the Work

Order

Review the work order carefully to be certain you can make the application safely, correctly, and legally, according to the label and state and federal regu

lations. You should be able to perform the requested work with reasonable precaution and within the expectations of normal work procedures for both yourself and the ground crew. Take into account the following factors when evaluating a work order.

Features and Limitations of the

Aircraft

The aircraft must be operationally ready to perform the aerial pesticide application. Be sure that the operator you work for has a procedure in place to prevent use of an unsafe aircraft or faulty dispersal equipment and to notify you in situations when you or others should not fly the aircraft due to maintenance

issues or mechanical malfunctions. This includes involving the company’s job scheduler in all company proce

dures for grounding an aircraft. Take responsibility for notifying the operator of problems that may affect the safety or efficient operation of the aircraft or involve your safety equipment. This

includes:

• Developing a way to communicate details of the problem to the person in charge.

• Establishing a timeline in which the problem needs to be corrected.

• Verifying that the problem is cor

rected before putting the aircraft or equipment back into service.

The aircraft must be capable of safely delivering the appropriate amount of pesticide to the target site. It must:

• Have the power and perfor

mance capabilities for the routine maneuvers needed to carry out the application, as well as being able to perform emergency maneuvers.

• Have a maximum load capacity that will accommodate the weight of the pesticide and, if needed, be able to handle takeoffs and landings from short, rough, or temporary airstrips.

• Be properly equipped to discharge the recommended amount of pes

ticide product per unit (acre) of target site area.

• Be able to produce and deliver spray droplets that provide an effective application and have low spray drift potential at the intended location.24 C H APTER 2 Pilot Qualifications and Limitations

Your competence, alertness, and capacity for timely and accurate judgment largely determine the safety of the operation and the quality of the application. In addition, your attitude about making safe and legal applications goes a long way in positively influencing others to accept and follow the safety procedures. You must be:

• Aware of your personal limitations in operating the aircraft and be fully aware of the features and limi

tations of the aircraft.

• Capable of executing emergency maneuvers appropriate to common emergency situations that you might experience.

• Capable of safely maneuvering the aircraft under normal flight

conditions when it is loaded to its maximum legal weight. • Able to determine the best direction in which to apply the pesticide to reduce its off-target movement.

• Capable of immediate and clear communication exchanges with on-site ground crew members and

others.

• Sufficiently rested to accomplish the job safely.

• Able to establish and follow realistic task deadlines and work patterns.

• Knowledgeable of weather factors and their influence on aerial appli

cation work.

• Able to correctly interpret and follow the pesticide label directions and work order and observe any state regulations regarding aircraft setup or product restrictions.

• Familiar with each pesticide product label to know first-aid

measures in the event of accidental overexposure, special precautions required for aerial application, and registered crops or sites.

• Able to recognize different types of crops from the air in order to

ensure the correct site is treated.

• Able to delineate boundaries of adjacent nontarget areas.

Take the following measures to reduce the potential for spray droplets to drift off the application site:

• Use a nozzle type, size, pressure, and orientation that maintains the desired droplet spectrum.

• Ensure that positive shut-off valves are working properly.

• Achieve good field-end coverage on initial spray runs (crossing the ends of fields that are bordered by trees or other obstacles usually means flying higher and increasing the chance of drift).

• Maintain applications at the appro

priate height for the aircraft type and speed.

• Use a boom length that does not exceed 75% of the wingspan of Robert Wolf—Kansas State University California Agricultural Aircraft Association25 Operati o n and A pplicati o n Safety fixed-wing aircraft or the rotor diameter of rotary-wing aircraft in order to reduce drift caused by wing tip and rotor vortices.

• Consult the pesticide label for rec

ommendations on boom type and setup requirements.



### Scouting the Target Site

Each application site may contain unique obstacles and hazards. Before committing to make an application, someone from the operation should visit the target site to identify obstacles, hazards, and sensitive areas. Do this by ground, by air, or both. Afterwards,

coordinate visual observations with maps and photographs of the area. Should the application site and sur

roundings be unfamiliar, seek more information regarding weather pat

terns, topography, and sensitive areas from the property operator and other people familiar with the area. During scouting, collect information about the:

• Location of the site and the size and shape of the area to be treated.

• Types of crops adjacent to the application site.

• Proximity of the site to adjacent

fields and other areas where field workers may be present.

• General local weather conditions.

• Proximity of the site to areas used or inhabited by people, including residences, parks, schools, play

grounds, shopping centers, businesses, roadways, adjacent fields, work crews, and other

areas.

• Proximity of the site to environ

mentally sensitive areas such as lakes, streams, ponds, irrigation canals, riparian zones, wildlife habitats, sensitive plants, nearby crops, and organic farms.

• Proximity of the site to farms, ranches, or other businesses

with livestock or other domestic animals, such as dairies, feedlots, swine operations, dog kennels, and

horse stables. • Proximity of the site to honey bee hives and other commercial pol

linating insects.

• Safety hazards such as power lines, guy wires, vent pipes, antennas, towers, trees, and other obstacles adjacent to the site and within the

site itself.

• Current cultural practices taking place at the site and other adjacent agricultural areas.

• Possible limitations to the oper

ation, such as ground crew access

to the site.

Charting all sensitive areas and obstacles will prove useful during the operation and for future reference. Established aerial pest control operators often have a collection of maps and aerial photographs that identify hazards and sensitive areas. Be sure to keep these up-to-date. Prior to the actual appli

cation, make a final check to confirm there are no recent changes that would put you, other people, the property, or the surrounding areas at risk.



### U nderstanding P esticide

Label Restrictions

Review the pesticide label to under

stand the legal requirements and use restrictions for that material and desig

nations of which type of aircraft is or is not acceptable. If the recommendation

or work order calls for a tank mix of two USDA—ARS Image Library26 C H APTER 2 or more pesticide products, review the labels of all the products to ensure you can combine them legally and that there are no compatibility issues. Follow the directions of each label having the most restrictive requirements for application, mixing, personal protective equipment,

and other factors. You must understand the pesticide label.

Application Instructions

Confirm that there are no prohibi

tions to applying any of the prescribed materials by air. Check to see if there are restrictions such as buffer areas, spray material dilution parameters, air temperature requirements during appli

cation, and time of day spraying.

Personal Protective Equipment Requirements

Understand the PPE requirements

on the label or labels and have available the most restrictive PPE required for handlers and you when you are outside of the aircraft cockpit. Make sure your flight suit, safety harness, and flight helmet are in good condition. Remove pesticide PPE before entering the air

craft cockpit.

First Aid and Decontamination Requirements

Read the label or labels for instruc

tions on what type of first aid and decontamination procedures to follow in case of pesticide exposure.

Sensitive Crop Restrictions

Review all label precautions regarding applying the material onto or near sensitive crops or other plants.

Notification and Posting Requirements

Understand the responsibilities for informing people about hazards prior to making an application and any require

ments for preventing entry by workers or people from the surrounding areas. Pesticide labels may require oral notifi

cation, field posting, or both. According to the Worker Protection Standard, agricultural employers are responsible for this notification and, when required, posting. However, aerial operations often post fields as a service to their clients. Never begin an application until the grower, property manager, or you meet the notification and posting requirements.

Honey Bee and Other Pollinating

Insect Restrictions

Check the labels to see if the materials you are applying are harmful to foraging honey bees and other pol

linating insects. If the label has such warnings or restrictions, adjust the application time to coincide with times these insects are most predictably not in the field you are treating.

Environmental Hazards

Check for precautions relating to environmentally sensitive areas, protecting natural enemies and ben

eficial insects, and other environmental

hazards.

Cleaning Application Equipment

After each use, clean and decon

taminate application equipment. Even some very small quantities of residues remaining in a tank can contam

inate subsequent pesticide mixtures resulting in crop damage. Other times residues may affect tank mix compat

ibility or the toxicity of a subsequent product. Be particularly careful and

clean between herbicides. Some her

bicide labels bear explicit instructions on tank cleaning; make sure you follow their instructions and use their pre

scribed cleaning materials.

Rinse the inside of the tank with water. If necessary, decontaminate it by using an appropriate tank cleaning material; common cleaners are ammonia or commercial tank cleaning product (e.g., 1 quart of household ammonia to each 25 gallons of water). Buy commercial pesticide tank cleaning and neutralizing compounds from chemical suppliers and farm equipment dealers. Be sure to check the pesticide label for any precautions regarding the use and disposal of cleaning and decontaminating chemicals. Follow the

directions for the amount of cleaner to use for your spray tank. Be sure to run pumps and agitators, and flush all hoses and booms. Wear appropriate PPE and eye protection. PRE V ENTIN G

EN V IR O N M ENTAL

H A Z ARD S P. O’Connor-Marer—Roseville, CA27 Operati o n and A pplicati o n Safety Pesticide residue on the outside of application equipment can be hazardous to people who must operate or repair this equipment. Wash the outside of spray equipment with water, using a small amount of detergent if necessary. Clean equipment in an area where you can contain runoff. Otherwise, clean the equipment at the application site.



### Resolving Conflicts

If the work order appears to be in conflict with any of the previously-listed factors, or if you or others have any safety concerns, delay the application until you and the property manager agree on modifications that resolve the conflicts and concerns. Resist pressure to perform an aerial application that presents high levels of risk. Also, refuse any job that is clearly illegal or not in compliance with any of the pesticide labels. Never apply a material for pest control that the EPA has not registered as a pesticide. This includes household and other products whose labels do not have EPA Registration numbers, such as soaps, spices, and vinegars.



### Reviewing and

D ocumenting the
Application

After completing an application, especially a challenging one, spend time with the ground crew to identify parts of the operation that went especially well and things you could improve when working in another similar situation. Examine possibilities of better planning, better communication, making different adjustments to the equipment, using different equipment, becoming more familiar with the target site, or changing other aspects of the application process. A debriefing such as this will take a little time, but will improve efficiency and fine-tune future operations.

Record Keeping

Keep records of every application. Federal regulations require keeping records of certain information when youmake applications of federally restricteduse pesticides, and some states require keeping records of all agricultural pesticideapplications—restricted- and generaluse (www.pesticidestewardship.org). To comply with federal record keeping when you make an application of fed

erally restricted-use pesticides, you must

have a record of the:

• Date (month, day, and year) of the application.

• Brand or product name of the pes

ticide material applied.

• EPA registration number.

• Total quantity of pesticide product

used.

• Location where you made the application.

• Size of the treated area.

• Name and certification number of the applicator.

Regulations require the operator to provide this information to the grower or property manager for whom you made the application within 30 days of the application. Federal regulations require the operator to keep copies of

these records for a minimum of two years; state requirements may differ. In addition to meeting federal and state requirements, application records are useful and important information for future reference and should ques

tions or problems show up after an application. Consider including in the application records some or all of the following additional or more detailed information about the application. This documentation will serve in your defense in case of possible legal action due to crop damage or off-target movement of the pesticide:

• Description of the application site, including type of site or crop

treated.

• Proximity of the treated area to roads, structures, other crops, field workers, hazards, and sensitive

sites.

• Recent or ongoing cultural prac

tices (such as irrigation) at the application site.

• The date and time the application started and the time the application

finished.28 C H APTER 2 • Weather conditions at the time of application—air stability, tem

perature, humidity, wind speed,

and wind direction recorded in degrees using a compass.

• Any changes in weather con

ditions occurring during the application.

• Names and amounts of all pesti

cides and adjuvants applied, and

the dilution rate.

• Application equipment configu

ration, including nozzle type, size, spacing, pressure, and orientation.

• Application pattern and directions in which you flew the swaths.

• Application speed and height. • Precautions taken to protect sen

sitive areas.

• Location of the mixing-loading

site.

• Routes taken for ferrying between the loading site and target area.

• Names of ground crew members and people present at the site during the application.

• Observations made by you, the ground crew, or others that may have had any influence on the operation.

Save all electronic files from an application, including flight data and

the as-applied map files from the GPS system. These files serve as documen

tation for much of the information included in your records.



### p lanning f or e m ergencies



## A very important part of the application planning includes being prepared for any emergency that might occur during the operation. Having a written emergency response plan, and sharing and dis

cussing this plan with the ground crew, helps everyone know how to respond and reduces the possibility of injury or death. Emergency planning must include providing ground crew members at the loading zone and satellite strips with emergency telephone numbers. Equip the aircraft and loading areas with

first-aid kits and ensure the aircraft has a working and properly-labeled fire extin

guisher. Have a complete spill cleanup kit at the loading area. Develop a plan of action for ground crew members to follow in case your aircraft is overdue at the loading site or home base. Train everyone in emergency response by actually play acting on how to deal with different emergency situa

tions. Practicing also helps to point out deficiencies in the emergency response plan so you and the ground crew can

correct them.



### Emergency Information

Locate the nearest medical facility to the application site and provide each crewmember with instructions on how to get there. A good strategy is to discuss the type of operation and its hazards with staff of nearby medical facilities to prepare them in advance for possible pesticide emergencies. Train all members of the ground crew how to direct emergency responders to the application or mixing-loading site. Equip members of the application operation with cell phones or radios to call for emergency help or to arrange transport of an injured person to a medical facility. Provide them with telephone numbers of the local hospital, fire department, police or sheriff’s department, and local Flight Standards District Office (FSDO). These numbers may change when using different landing areas, so prepare lists for each specific location.



### F light H azards

Whenever possible, have a ground crew member present at the application site who is able to communicate with you during the entire operation. This person can warn you of hazards and notify you of problems on the ground that require stopping or delaying the application. The ground crew member should com

municate with anyone on the ground29 Operati o n and A pplicati o n Safety who might be at risk during the appli

cation, and take action to warn them or

escort them from the area. Provide this ground crew member with a map that

shows the hazards and sensitive areas within the application site and in sur

rounding areas.



### P lans in Case of Aircraft

Crash

Make emergency plans for cata

strophic events such as aircraft engine or landing gear failure leading to a forced landing or crash. This requires training every member of the ground crew to respond immediately, act promptly, stay calm, and focus on helping you. Should a crash occur, switch off the aircraft’s batteries and shut off its fuel line. If you are uninjured yet unable to open the cockpit door, break open a window and exit the aircraft as quickly as possible. Instruct ground crew to get to the crash site immediately with a fire extinguisher

and to communicate the exact location of the site to emergency responders and others by cell phone or radio.



### Application Equipment

M alfunction

Application equipment mal

function could include ruptured hoses or lines, a tank leak, pump failure, nozzle and check valve leaks, or electronic con

troller failure. Any of these problems risk contaminating areas outside of the target area and may require a load jet

tison before the aircraft can return to an airport for repairs. Prepare for this type of emergency by locating pos

sible places to jettison the load or to set down the aircraft. Any route you take with an aircraft having a pesticide leak should be over areas not occupied by people or animals. To protect the public when experiencing any emergency of this type, FAA regulations permit you to deviate from required flight patterns

and other restrictions.



### Ground Crew Emergencies

Ground crew emergencies include leaks and spills of concentrated pesti

cides or diluted spray materials as well as splashes or spills that contaminate one or more of the ground crew members. It could also be a fire involving pesticide materials. These serious problems require immediate action to protect people and the environment. Regulations require that pesticide labels be at the use site, which includes the area you are spraying, in addition to the mixing-loading site. There is an exemption to this requirement for aerial applications as long as you maintain radio contact with the ground crew and any flaggers. Labels serve as references for emergency personnel responding to accidents involving spills and they provide first-aid information in case of pesticide exposure. The ground crew must first take steps to prevent any human exposure and then immediately control, contain, and clean up spills or leaks to prevent further contamination of the mixing-loading area. Preparations for a leak or spill emergency includes training and prac

ticing cleanup procedures and having an adequately equipped spill cleanup kit at the mixing-loading site at all times.Train handlers performing the mixingloading jobs on proper ways to clean up a spill (see Appendix 4). Provide them with a cell phone or radio to summon help for major spills or in case of a pesticide fire

or other emergency. Keep instruction sheets at the mixing-loading site for cleaning up spills, dealing with pesticide fires, and situations requiring assistance from fire fighters or emergency medical

technicians.

Train handlers how to follow the first-aid information on the pesticidelabel if someone involved in mixingloading activities gets exposed to a pesticide. Be sure there is sufficient clean water for emergency eye washing

and decontamination of the entire body. Have soap and single use towels available at the mixing-loading site along with changes of clothing for each

crew member.



### Overspray, D rift, and

Other M isapplication

As the applicator, you assume responsibility for any pesticide mis

application. Overspray, off-target movement, and other types of misap

plication may damage surrounding30 C H APTER 2 crops, residential plantings, landscapes, and other property, as well as cause

environmental contamination. These are all violations of pesticide labels as well as many state pesticide control laws. Train ground crews to be alert during an application and quickly communicate with you if they spot any potential for such problems. Considerable financial liability and legal consequences may result from any damage caused by mis

application.



### Spray or D ust Contacting
Bystanders or Vehicles

It is illegal to apply any pesticide in a manner that exposes people, livestock, vehicles, and other objects to the spray or dust. Unfortunately, farm workers, joggers, trespassers, and others may not rec

ognize the hazard of entering an area until an aircraft making an application flies over them. Weather patterns, especially wind direction, can also change rapidly, causing pesticide from the application to move off site and possibly onto workers or other people nearby. For example, you might plan and begin an application based on the wind blowing away from nearby areas where people are present. However, during the application the wind direction could change and blow towards these areas. Therefore, develop a plan that includes commu

nication between you and the ground crew to delay or stop the application if anyone spots people nearby, and only make applications if no one is in adjacent areas where they might be subject to exposure. Inspect the appli

cation site and adjoining areas before beginning an application to confirm

no one is around the site. In the emergency plan, include instructions to follow if spray con

tacts bystanders. This should involve decontamination methods and proce

dures for obtaining medical care for exposure victims.



## O perational problems can result from poor communications or sketchy infor

mation about jobs the ground crew performs. It is risky to assume that ground crew employees already possess all the vital information they need to carry out their jobs safely. Job delays, having to return for forgotten materials, treating the wrong fields, or spraying improper pesticide types, formulations, or concentrations are examples of mis

takes that may occur when ground crew employees are operating with incom

plete information. Involve the supervisor and ground

crew in:

• Developing maps of all areas to be treated and charting all hazards, adjacent crops, and environmental

sensitive areas.

• Scouting all new areas and keeping maps up to date so you can identify new obstacles or changes in condi

tions promptly. • Developing a system for accepting or transmitting information between you and the ground crew on work order changes in the field.

• Filling out mix sheets and deter

mining the order of mixing spray

batches.

• Ensuring that mixer/loaders are trained in calculating tank batches, pesticide handling procedures, and the use and care of personal pro

tective equipment.

Provide the ground crew with essential site-specific job information and make sure they have a checklist outlining the steps to take to comply with applicable regulations and companypolicies. Develop and complete an upto-date Standard Operating Procedures (SOP) for ground crew members to

use and make sure it is available at the loading site. This is especially useful when communication with you is impaired and ground crew members dis

agree or are uncertain about procedures such as mixing batches of pesticide spray. 

### co mmu nications31 Operati o n and A pplicati o n Safety 1. The type of first aid given to a pesticide exposure victim depends on the:

A

. Type of exposure.

B. Age of the victim.

C

. Training of the person administering first

aid.

D

. Work situation where the person received the exposure.

2. If a person shows signs of pesticide poisoning,

he or she should:

A

. Stop working for the day.

B. Receive immediate medical attention.

C

. Be assigned to another job not involving pesticides.

D

. Be scheduled for a blood test.

3. If a person spills liquid pesticide onto his or her arm, the amount of exposure and injury can often be reduced by:

A

. Wiping arm with antibacterial wipes.

B. Wiping the liquid off the person’s arm.

C

. Covering the exposed area with a damp

cloth.

D

. Washing the exposed area with soap and

water.

4. During an application operation, pilots must wear the label-required personal protective equipment for pesticide handlers:

A

. Only while making an aerial application.

B. Anytime they are in the aircraft cockpit.

C

. While making nozzle adjustments.

D

. Only when mixing and loading. 5. First-aid instructions to use for pesticide exposure is found on:

A

. Pesticide labels.

B. OSHA’s Emergency Response website.

C

. Supplemental labeling.

D

. Manufacturer literature.

6. An up-to-date Standard Operating Procedures (SOP) document is useful to ground crew members especially when:

A

. The communication channel with the pilot

is lost.

B. The pilot begins applying the pesticide in a

manner inconsistent with the work order.

C

. Trying to determine the best time for applying the pesticide.

D

. The pilot applies the pesticide to a site not

listed on the label.

7. For protection of the surrounding community,a good reason for securing pesticide application aircraft and other equipment when not in

use is to:

A

. Prevent weather damage to the equipment.

B. Protect employees from pesticide exposure.

C

. Prevent intruder access to the equipment.

D

. Comply with regulatory agency mandates. 

# CHAPTER 2: 

# O perati o n and 

# A pplicati o n 

# S afety Review Questions32 C H APTER 2 8. At a minimum, the training that ground crews must receive as pesticide handlers is required to be performed:

A

. At the beginning of each operation.

B. Annually, before performing handling

activities.

C

. Every two years, before performing handling activities.

D

. Every five years, before performing handling activities.

9. Chances of pesticide exposure greatly increases if a pesticide handler fails to:

A

. Read the Statement of Practical Treatment on the pesticide label.

B. Take frequent breaks during handling

activities.

C

. Drink adequate water during handling

activities.

D

. Wear the required personal protective
equipment. 10. Good communication with the ground crew before and during an application operation may result in:

A

. Greater chances of accidents.

B. Inability for the ground crew to perform their tasks properly.

C

. Fewer job delays.

D

. Improper spray mixes.

RE V IE W QU E S TI O N AN SW ER S O N PA G E 9733 Preventing Pesticide D rift 

# P reventing 

# P esticide 

# D rift

P esticides are essential tools in man

aging pests in a particular location, but confining the pesticide to the intended target during application is an important responsibility. Reducing drift and off-target pesticide movement is necessary when you make any type of pesticide application because, if not con

trolled, this off-target movement can contribute significantly to the pesticide load in the environment. However, you must take steps to control drift of the pesticide material away from the target area during an application.
Off-target movement of pesticides is the condition where pesticides or pes

ticide residues leave the application site at any time and in any manner other than during a pesticide application. Often the physical and chemical char

acteristics of the pesticide contribute to

or reduce the chances that the material may move offsite after an application. For example, pesticides that break down quickly after you have applied them will be less likely to move off the application site than pesticides that are highly per

sistent in the environment. Pesticides and pesticide residues can move off the application site in several ways after they are applied.

These include:

• Post-application volatilization into the atmosphere of the pesticide that adhered to treated surfaces, the crop plants, the soil in between the plants, or bare ground—pesti

cides with high volatility are more likely move off the application site than pesticides with low volatility.

• Leaching through the soil at the application site and moving into surface or ground water after application—pesticides with low solubility in water will not leach as much as those that are very soluble

in water. This chapter will assist you to:

• Understand what off-target pesticide movement is and knowing the

difference between drift and off-target pesticide movement.

• Recognize the way droplet size contributes to drift or reduces drift
potential.

• Recognize the factors and conditions that contribute to drift and off-target pesticide movement.

• Learn how to minimize drift and off-target pesticide movement. 

# CHAPTER 3

LEARNING OBJECTIVES34 C HAP TER 3 • Rainfall or irrigation water washing residues off the application site into surface waters after appli

cation—pesticides that have a high absorption potential are less likely to wash off plant surfaces.

• Blowing off the site attached to soil particles or dead plant material after application.

• Leaving the application site as residues on harvested crops.

• Being carried off the application site on vehicles, equipment, animals, and people.

• Being carried off the application site

as fine droplets in an inversion cloud.

The National Coalition on Drift

Minimization (NCODM) defines spray
drift to be “the movement of pesticide through the air at the time of pesticide application or soon thereafter from the target site to any non- or off-target site, excluding pesticide movements by erosion, migration, volatility, or windblown soil particles after appli

cation.” Pesticide drift includes pesticide droplets, vapors, or dust particles that move off the application site after leaving the dispersal system but before adhering to the intended treatment site during a pesticide application. This includes vapor or droplets that concentrate in an inversion layer during an application. During any application, a certain percentage of the spray droplets will

drift. If this drift is confined to the treatment site so that it is part of the pesticide application, there is generally

little hazard to the surrounding areas that are not part of the application. Pesticide drift, however, increases

the hazard to people and other living organisms outside of the treatment site. The following information pertains to recognizing the causes of pesticide drift and ways to reduce this problem.



### f

actors t h at contrib u te to d ri f t



## T he spray droplets and the percentage

of droplets within a certain size range are the key factors affecting off-target

drift. You can control some of these factors when making aerial applica

tions.

The unit of measure for the diameter of a spray droplet is a micron (also referred to as a micrometer). The mathematical symbol for a micron or micrometer is μ. One micron is 1/25,000 or 0.00003937 of an inch. To illustrate the relative size of one micron, a single sheet of paper is about

100 microns thick. The longer a spray droplet remains airborne or suspended in the air, the greater the chance it will drift from the application site. A small spray droplet is more susceptible to drift than a larger droplet because the small droplet is lighter and therefore remains airborne much longer. For example, while it takes approximately 4 minutes for a

COMPARISON OF DROPLET FALL RATES

DROPLET DIAMETER 20

microns 100

microns 240

microns 400

microns

4 minutes 11 seconds 5 seconds 2 seconds TIME TO FALL 10 FEET35 Preventing Pesticide D rift 20-micron droplet to fall a vertical dis

tance of 10 feet, it takes only 2 seconds for a 400-micron droplet to travel the

same distance. There is a rapid decrease in the drift potential of droplets larger than about 200 microns. Conversely, research has proven that droplets smaller than 200 microns are very prone to drift. People who study drift classify droplets that are 150 to 200

microns or smaller as driftable fines . In wind speeds ranging from 1 to 9 mph, droplets that are 200 microns or larger have an insignificant drift potential. For example, the theoretical distance that spray droplets move laterally while falling from 10 feet above the ground in air moving at 3 mph would be only about 8 feet for 400-micron droplets. However, this distance increases to about 1,000 feet for 20-micron droplets. Higher velocity winds increase the drift potential of all droplets. Droplets below 50 microns in diameter remain suspended in the air indefinitely or until they evaporate. Droplets of this size have no benefit to a pest control program, other than certain vector control operations, because they are never likely to reach

target surfaces. Avoid using nozzles or nozzle orientations and configurations

that produce droplets in this size range because there is no way to assure that these droplets will remain on or near the application site.



### Classification of D roplet

Size

All nozzles produce a range of droplet sizes, known as the droplet-size

spectrum

. This means that even when

you use a nozzle having a large orifice that mainly produces large droplets, some percentage of the droplets in the spray are going to be small enough to be prone to drift.

A common classification method

used to describe the droplet-size

spectrum produced by a nozzle is the

volume median diameter (VMD). This means that half of the total spray volume

of that nozzle consists of spray droplets

smaller than the VMD numerical value, while the other half is larger

than the VMD numerical value. For instance, a nozzle with a VMD of 400 microns sprays out half its total volume in droplets having a diameter greater

than 400 microns and the other half in droplets having a diameter smaller than 400 microns. However, this does not 20 microns

8 ft LATERAL MOVEMENT OF DIFFERENT SIZE DROPLETS

50 microns

100 microns

150 microns 10 ft

400 microns WIND SPEED = 3 MPH

22 ft 45 ft 178 ft 1056 ft

LESS
THAN 400 μ

GREATER
THAN 400 μ

V olume Median D iameter = 400 Microns36 C HAP TER 3 tell you how much of the spray volume is made up of droplets that are smaller

than 200 microns. Another way of classifying the droplet sizes produced by a nozzle is to identify the percentage of the total spray volume that contains droplets smaller or larger than a specific diameter, usually 200 microns. This directly addresses those droplets at risk for drift.

For instance, a nozzle may produce 2 percent of its total spray volume in droplets smaller than 200 microns in diameter. This means that only a small portion of the droplets produced by this

nozzle are at risk for drift. This type of description, however, tells nothing

about the size of the remaining droplets produced, which is the information you need to determine the type of coverage

you can expect. The most useful way to describe the droplet sizes produced by a nozzle is to

use droplet-size categories based on the

entire droplet-size spectrum of a nozzle,

rather than just the VMD or a specific

size droplet by percentage of volume. This spray-classification system is the American Society of Agricultural and Biological Engineers (ASABE) standard S-572.1: Spray Nozzle Classification by Droplet Spectra . This classification system has eight categories: extra fine, very fine, fine, medium, coarse, very coarse, extra coarse, and ultra coarse (see chart on next page). Using these categories, you can select a nozzle,

orifice size, and operating pressure that produces the label-recommended droplet-size spectrum. All pesticide labels will eventually

contain nozzle specifications and/or the required droplet-size spectrum. The chart on page 37 shows the standard droplet size categories and color coding. Consult the pesticide label for specific instructions when selecting

nozzles. Using the droplet-size spectrum categories, determine which

nozzle to use to reduce drift and provide adequate coverage in a particular application operation. By selecting the appropriate category based on the type and use of a pesticide, you get acceptable results while keeping the risk of drift to

a minimum.



### Spray Mixture Physical
Properties

Three key physical properties of a spray mixture have a significant effect

on droplet size in aerial applications.

Dynamic Surface Tension

Surface tension is the force that keeps a droplet together. When the fluid that makes up the droplet con

tains adjuvants or other substances the normal surface tension changes, but it

takes a certain amount of time for the molecules in the adjuvants to move to the surface of the droplets. Therefore, the surface tension of spray droplets can change after the droplets are formed, causing a larger droplet to split into smaller droplets.

Extensional Viscosity

When the pump forces spray liquid through a nozzle orifice, it stretches to a certain point before breaking off to form a droplet. The amount of stretching or “stringiness” is the extensional viscosity. Pressure in the system, which regulates the ejection speed of the liquid, affects the extensional viscosity. Higher pressure lowers this viscosity, therefore pro

ducing smaller droplets.

SHEAR

VISCOSITY

EXTENSIONAL VISCOSITY DYNAMIC SURFACE TENSION37 Preventing Pesticide D rift Shear Viscosity

Shear viscosity is a liquid’s resistance to flow. Some liquids are thicker and therefore resist flow or flow more slowly than less thick, or less viscous, liquids. Spray drift control adjuvants, when added to the spray mixture, may help reduce the number of driftable droplets under certain conditions. However, reports indicate that some types of drift control agents lose their effectiveness when circulated through a sprayer pump.

Studies show that some materials sold as drift control adjuvants actually do not perform as such. Spray drift control adjuvants are a specific class of chemical adjuvants, so do not confuse these with other adjuvants such as surfactants, wetting agents, spreaders, and stickers. These other adjuvants, and formula

tions containing alcohol or certain water miscible solvents, tend to reduce the dynamic surface tension of spray droplets, resulting in smaller droplet sizes.



### External F actors Affecting

D roplet Size and D rift

Certain factors remain beyond your control. These external factors include weather such as humidity, rain, extremely high or low temperatures, wind, or conditions leading to an inversion layer.

Effects of Evaporation on Droplet Size

Once exposed to the atmosphere, individual spray droplets will gen

erally begin to evaporate. Evaporation removes water or other carriers, making the spray droplet smaller than it was

when it left the nozzle. As the droplet becomes smaller, it becomes more prone

to drift. Conditions that contribute to evaporation include:

• Air temperature –evaporation is more

rapid as temperature increases. Extra Fine

Very fine

Fine

Medium

Coarse

Very Coarse

Extra Coarse

Ultra Coarse XF

VF

F

M

C

VC

XC

UC PURPLE

RED

ORANGE

YELLOW

BLUE

GREEN

WHITE

BLACK Droplet Spectrum

Category Symbol Color Code

This standard defines droplet spectrum categories

for the classification of spray nozzles relative to the

specified reference fan nozzle. The purpose of this

classification is to provide the nozzle user with droplet

size information primarily to indicate off-site spray drift

potential and secondarily for application efficacy.

Refer to product labels for specific guidelines on a droplet spectra category required for a given application situation.

Nozzle manufacturers provide information necessary

to place nozzle types into a droplet spectrum category

based at least on orifice size and pressure. The color

code is an industry standard. 

### ASABE STANDARD S-572.1 Spray Droplet Spectrum Categories

EFFECTS OF EVAPORATION ON

DROPLET SIZE38 C HAP TER 3 • Humidity —evaporation is more rapid as humidity decreases.

• Air movement —evaporation is more rapid as air movement increases.

• Distance from discharge to the

target —the further the droplet has

to fall the more time is available for evaporation.

• Spray carrier —water will evaporate

faster than oil carriers.

The optimum time to make an aerial application when evaporation of spray droplets is a concern is during the

coolest part of the day. Early morning is usually ideal because it is generally more humid at this time and wind speeds are often low. However, temperature

inversion conditions may be greater during early mornings. Avoid making applications during hot, dry periods of the day. Keep the application height between 8 and 12 feet from the target to shorten the distance that spray droplets

must fall. To minimize the risk of drift caused by evaporation, small droplet sprays require lower application heights.

Co-Distillation

Pesticides can also move offsite through a process called co-distillation

. This phenomenon occurs when the pes

ticide contacts very hot surfaces, usually soil with no vegetation. Pesticides, even those that are not highly volatile, leave

the soil surface with water molecules during rapid evaporation that occurs immediately after irrigation. Fog also is able to pick up pesticides from the application site and carry them offsite.

Effect of Wind and Thermals on Drift and Off-Target Movement

Air movement from wind or thermals is a major contributing factor to off-target pesticide drift. Wind carries lighter and smaller droplets away from the target site where they accumulate until they saturate a given volume of air with the pesticide. As winds become stronger, the air traps more and more larger droplets and may move them away from the target before they return to the ground. Upward air movement caused by thermals also entraps and moves small droplets, increasing the probability that they will drift away from the application site. Thermals occur as the ground heats up, usually in the afternoon, and especially after cool night temperatures. This causes air near the ground to rise,

since warm air is lighter (molecules are further apart) than cool air.

Temperature Inversions

Differing air temperatures in stratified layers of the atmosphere are responsible for the inversion phe

nomenon that can exacerbate the problem of off-target pesticide drift. Inversions occur when an upper layer of

air is warmer than the air below it. This warm air cap may start at 20 to 100 or more feet above the ground and block the cooler air below it, preventing ver

tical air movement. Over a wide area, it may be pos

sible to identify the presence of an inversion condition by checking with

the National Weather Service. In some areas, during certain times of the year, temperature inversions occur regularly. One method for detecting

a temperature inversion in a localized

area is to observe a column of smoke rising into the air. Sometimes, dust from agricultural operations may serve the same purpose. If the rising

smoke column or dust cloud flattens and begins moving sideways or col

lects in one area above the ground, an inversion condition probably exists. Do not make applications during

an inversion condition because the inversion layer traps fine spray

WARM AIR

COOL AIR



### 0 ft 10 ft 20 ft 30 ft

T e mp er a ture inversi o n39 Preventing Pesticide D rift droplets and pesticide vapors. These become concentrated, similar to smoke particles in the smoke column. Rather than dispersing somewhat evenly throughout the atmosphere over a relatively large area, the pesticide often moves as a concentrated cloud away from the treatment site. Afterwards, the concentrated pesticide cloud will return to the ground and may cause problems for people, non-treated crops, and other living organisms.

An inversion condition can occur when the air is calm with very little air mixing. This condition makes it possible for the cloud of spray droplets or vapor to move slowly downwind. Temperature inversions generally begin before sunset and remain into early morning or near bodies of water.



## D rift research shows that nozzles and other spray components can produce large spray droplets that have less of a tendency to drift. However, when improperly used, wind shear effects on

nozzles result in drift-prone smaller droplets. Appropriate airspeed and

proper nozzle orientation are the two factors that reduce wind shear effects.

You need to find a balance between the aircraft’s minimum airspeed needed for covering the desired acreage in a given period and the maximum airspeed before wind shear impacts the size of spray droplets. In addition to selecting proper

nozzles and finding the balance

between proper airspeed to minimize

atomization of large droplets, the other challenge you face is to find a balance between drift reduction provided by large droplets and good coverage asso

ciated with smaller droplets. Research conducted by pesticide manufacturers, the pesticide application industry, universities, and state and federal regulatory agencies demon

strate that you can minimize off-target pesticide drift during any application operation by:

• Selecting nozzle types with orifice

sizes that produce large droplets— wider spray angles typically produce finer sprays.

• Using a nozzle orientation straight

back in relation to the aircraft’s level flight line so that the dis

charged spray is least affected by

wind shear across the nozzle face, therefore maintaining the rated

desired droplet size (some research is showing that a slight angle of about 5 degrees allows the spray

to be directed downward without affecting droplet size).

• Confining boom length to no more than 75 percent of the wingspan of a fixed-wing aircraft or the rotor diameter on rotary-wing aircraft, to reduce drift caused by wing tip

and rotor vortices.

• Increasing system pressure when flying at faster speeds to reduce the amount of smaller droplets. 0 degrees— largest droplets TRAVEL DIRECTION

45 degrees—
smaller droplets

90 degrees—
smallest droplets 

### minimi z ing o ff- target d ri f t40 C HAP TER 3 • Making sure the positive shut-off and suck-back systems are working properly.

• Accurately calibrating application equipment, including using a system pressure that is appropriate to the airspeed of the aircraft for maintaining a droplet size that results in optimal spray coverage.

• Using spray drift control adjuvants when appropriate to increase spray droplet size.

Spray droplets are normally finer at greater flight speeds, especially when using wide-angle fan nozzles or a nozzle orientation that is not straight back in relation to the level flight of the aircraft. However, for applications using straight

stream or narrow angle (20 to 40°) flat

fan nozzles pointed backward, increasing the spray pressure can actually result in a coarser spray if the exit velocity from

the nozzle becomes closer to the speed of the aircraft. Doing this reduces the

air shear effect.



### Application Techniques

Some application techniques for reducing off-target pesticide drift during an aerial application include:

• Leaving untreated buffer zones one, two, or more swath passes

wide within the treated site or field, along the downwind edges so that any pesticide that drifts will stay on the treated site; treat these

buffer zones later, when the wind

direction reverses into the field.

• Getting good field-end coverage on initial spray runs; end passes made to fields that are bordered by trees or other obstacles usually means flying higher, which increases the

chance of drift.

• Flying at the optimum airspeed that will, when combined with pump output pressure, help to maintain larger droplets. • Keepi ng application height

between 8 and 12 feet above the

target crop.

• Avoiding applications during weather conditions that promote off-target drift, such as high winds

or inversion conditions.



### Smoke Generators

You use smoke generators on the

aircraft to visualize air movement at the application site. You can also use it to identify inversion conditions below the application height. The smoke generator injects oil into the aircraft’s exhaust system, which burns to produce smoke. You control the oil injector with a switch inside the cockpit. When you activate the smoke generator, you can watch the smoke

movement to estimate the off-site movement potential for spray you are applying. Although of limited effec

tiveness, you can also use the smoke to locate the position of the previous pass to estimate where to begin the next pass. However, due to possible movement of the smoke in air currents,

this method is less reliable for swath marking. Smoke generators are a common part of the onboard equipment found on most agricultural aircraft. One

reason for this is that GPS systems have eliminated the need for human flaggers at the application site to position the aircraft for each swath. However, a flagger typically also provided you with information about wind speed and direction. Since off-target pes

ticide drift is a major concern during aerial applications, a smoke generator provides a better visual picture of wind direction and relative wind speed at the

time of spray release. Using a smoke generator before beginning the first pass of an application allows you to

make immediate local wind condition evaluations without depending on someone on the ground.41 Preventing Pesticide D rift 1. Managing off-target pesticide drift during an aerial application is:

A. The ground crew’s responsibility.

B. The property owner’s responsibility.

C

. The pilot’s responsibility.

D

. A requirement of a pilot’s FAA licensing.

2. Off-target pesticide drift is the offsite movement of the pesticide that occurs:

A. Any time after an application.

B. At the time of pesticide application or soon

thereafter.

C

. As residues on objects moving from the application site.

D

. Several hours to several days after an application.

3. The color code for a nozzle that produces spray droplets in the extra fine category is:

A. Black.

B. Red.

C

. Purple.

D

. Orange.

4. Generally, the optimum time for making an aerial application of a liquid when droplet
evaporation is a concern is:

A. Early morning.

B. Mid morning.

C

. Early afternoon.

D

. Late afternoon. 5. Which of the following factors has NO effect on off-target pesticide drift?

A. Nozzle orientation.

B. Spray pressure.

C

. Constant 3 mph wind.

D

. Physical properties of the spray mixture.

6. Wider-angle spray nozzles usually produce droplets than narrower spray

nozzles.

A. Coarser.

B. More uniform.

C

. Less uniform.

D

. Finer.

7. The most effective boom lengths for reducing

the amount of drift are:

A. 90% of the wingspan or the rotor span.

B. 75% of the wingspan or the rotor span.

C

. 65% of the wingspan or the rotor span.

D

. 50% of the wingspan or the rotor span.

8. Aside from external factors, the most impor

tant factors affecting off-target drift are:

A. Physical properties of the spray mixture.

B. Extremely high or low temperatures.

C

. The size of the spray droplets and the

percentage of droplets within a certain size

range.

D

. Conditions leading to a temperature inversion layer. 

# CHAPTER 3: 

# P reventing 

# P esticide 

# D rift Review Questions42 C HAP TER 3 9. Driftable fines are droplets in the size range of:

A. Larger than 500 microns.

B. 300 to 500 microns.

C

. 200 to 300 microns.

D

. 50 to 200 microns. 10. The droplet size at which spray drift becomes

a concern is:

A. 50 microns and below.

B. 100 microns and below.

C

. 200 microns and below.

D

. 300 microns and below.

REVIE W Q UESTI O N A NS W ERS O N PA GE 9743 Aeri a l Pesticide D is p ers a l S ystems 

# A eri a l 

# P esticide 

# D is p ers a l 

# S ystems

A ccurate metering and application of pesticides are the key purpose of all aircraft dispersal systems. Dispersal equipment has to deliver the labeled rate of a liquid or dry pesticide formu

lation uniformly and accurately.

Pesticide materials and the dis

persal system add considerable weight, requiring aircraft that can safely lift, transport, and make applications when fully loaded. Fixed-wing aircraft used for pesticide application are fast, maneuverable, and carry heavier loads than rotary-wing craft. A limitation of a fixed-wing aircraft is the need for a designated landing area, which may not always be close to the application site. Rotary-wing aircraft used for pesticide application are more maneuverable but slower than fixed-wing aircraft, and can operate over a range of speeds and in almost any area since they do not require a runway for takeoff or landing. This allows ground crews to perform loading operations at or near the application site. This chapter will assist you to:

• Understand the desirable requirements of an aircraft pesticide dispersal system for liquid and dry pesticide formulations.

• Become familiar with the components of an aircraft pesticide dispersal system for liquid and dry pesticide formulations.

• Understand the importance of inspecting, servicing, and maintaining dispersal systems.

• Become familiar with spray nozzles and how to correctly position

them on spray booms.

• Know how to test dispersal systems for appropriate spray patterns.

• Understand the features of, and how to change the settings on, dry

material spreaders. 

# CHAPTER 4

LEARNING OBJECTIVES

d is p ersal s y ste m re qu ire m ents



## T he main function of a dispersal system is to allow you to apply an accurate and uniform amount of pes

ticide material over the application site as efficiently as possible. Liquid dis

persal systems include a pump, a tank or hopper, hoses and/or metal lines, control valves with suck-back features, a pressure44 C HAP TER 4 gauge, filters, one or more booms, and nozzles. Pumps in these systems may be electric or hydraulic motor powered, wind-driven, or directly powered from the aircraft engine.



### Equipment and

Component Factors

Consider several factors for dis

persal equipment and components used for aerial application of pesticides. They

must be durable.

Corrosion Resistant

Many pesticide materials are cor

rosive, so only use corrosion resistant components in the dispersal system. Stainless steel, fiberglass, polyethylene, and polypropylene are non-corrosive, while steel, iron, and aluminum will corrode. In addition, acidic liquids may react with steel or iron to produce highly explosive hydrogen gas. Even though application components are corrosion resistant, the rest of the aircraft may not be, so regularly clean, inspect, maintain, and protect these parts.

Leak Proof

Make sure all components of the aircraft’s pesticide dispersal system can resist leaks during the rigors of takeoffs, landings, and flight. This includes tanks, pumps, agitators, bearings and seals, hoses, and hose fittings. The presence of pesticide residues on the belly of the aircraft could be an indicator of a leaking

hose or connection somewhere in the system. Leaks endanger you and can damage parts of the aircraft. In addition, leaks can expose workers to pesticide materials, contaminate places and objects used by people, and render runways, hangars, and other areas unusable until decontaminated. Leaks may also cause damage to crops and other plantings

outside of the treatment area.

Allow You to Make Accurate

Volume Measurements

The dispersal equipment has to include a way to measure accurate volumes of pesticide materials in order for you to apply the correct amount to

the treated area.

Able to Produce Uniform Flow

Volumes

The dispersal system should provide a uniform flow of the pesticide through the nozzles for even distri

bution of liquid sprays over treatment areas. Systems that adjust the flow volume according to the application air speed (referred to as flow control) provide the greatest application volume uniformity, but can affect droplet size.



### li qu i d d is p ersal s y ste m co mp onents



## I mportant qualities of liquid dispersal systems include being dependable and durable, as well as being uncomplicated to service and repair. Descriptions of major dispersal system components

follow. 

### Spray P umps
The spray pump maintains the pressure in the system to ensure a uniform flow volume and proper atom

ization by the nozzles. The pump also may power the tank agitation system

H YDR AU LIC POW ERED PU M P

M. J. Weaver—Virginia Tech Tom Hoffmann—Washington State Department of Agriculture F a n D riven PU M P45 Aeri a l Pesticide D is p ers a l S ystems that keeps the pesticide mixture in suspension. On fixed-wing aircraft, the most common power source for the pump is a fan mounted under the aircraft, below the tank. The aircraft’s propeller slipstream drives this fan. Some fan-driven pumps have variable pitch blades so you can change the pump speed, and thus output, for dif

ferent application requirements. Ultra low volume (ULV) applications may require modifications to the pumping system to make it suitable for such low

output. Other types of power sources for aircraft spray pumps include the air

craft’s hydraulic system or an electric motor that drives the pump. Pumps need enough power and capacity to meet the system’s nozzle pressure, flow volume, and tank agi

tation requirements. The pump needs some extra capacity to make up for pressure loss due to friction in the lines and to operate nozzle anti-drip check valves. If you use a pump with too little capacity, you need to reduce the swath width to get adequate uniform coverage. However, this wastes time and fuel. The centrifugal pumps commonly used on aircraft produce high volumes of spray material (up to 200 gallons per minute or more, depending on the size of the pump) at low pressure, usually ranging between 10 and 70 pounds per square inch (psi). Centrifugal pumps

made from aluminum with bronze or steel internal parts are most common. Centrifugal pumps have a high range of applications, including spraying abrasive wettable powders and flowable formulations, because there is no close contact between moving parts. These pumps usually require operating speeds between 1,000 and 5,000 revolutions per minute (rpm).



### P esticide Tanks and

Hoppers

Tanks and hoppers have to be cor

rosion resistant, and most tanks used in aircraft are fiberglass. Other materials used for tanks and hoppers include stainless steel, high-density polypro

pylene, or polyethylene. Stainless steel tanks or hoppers generally are more durable than plastic or fiberglass, but they are heavier, therefore adding additional weight to the air

craft. Overall, tanks and hoppers made of stainless steel require

less maintenance

and can withstand rougher handling

than those made of plastic or fiberglass. A l t h o u g h m o s t popular because of less weight, a disadvantage of fiberglass is that it absorbs pesticide liquids if its surface is scratched or abraded, pos

sibly contaminating future tank loads. However, scratches, small cracks, or punctures in fiberglass are easy to repair, while cracks or punctures in polypropylene and polyethylene tanks

are difficult to fix. Most tanks serve a dual use: they hold liquids for spraying and are hoppers for dry materials such as granular pesti

cides, fertilizers, and seeds. Tanks have top openings for filling, but it is easier to pump liquids through a pipe that has a quick coupling disconnect protruding through the side of the aircraft fuselage. A gauge or visual level that shows

the amount of material in the tank or hopper is necessary. This gauge has to be conveniently located so it is visible from the cockpit.

Interior baffles in tanks limit the sloshing of liquid during flight and dampen the effect of load shift on the aircraft’s stability. In case of an emer

gency when a load must be dumped in a matter of seconds, the tank needs a large valve or port at the bottom that you can open quickly. Tank vents are necessary and these should accom

modate a large enough passage of air to prevent a vacuum that would slow or stop the normal flow of liquid through the nozzles or bottom port. Adequate ventilation of the tank also prevents the buildup of hazardous fumes, explosive gases, or dusts that could damage the aircraft and even endanger your life. On fixed-wing aircraft, mounting the tank or hopper in front of the cockpit and as close as possible to the M. J. Weaver—Virginia Tech E X TERN A L S P R A Y T A N K W IT H QU IC K

C OUP LIN G DISC O NNECT46 C HAP TER 4 aircraft’s center of gravity reduces the

effect on the aircraft’s

t rim as t he tan kempties. Small rotarywing aircraft have either a pair of tanks,

with one mounted

on each side of the fuselage, or a single bel ly t a n k . W it h two tanks, a pipe or

hose connects them and allows the pump to draw the spray mixture equally from both, keeping the aircraft balanced. Larger rotary-wing

aircraft have a tank mounted on the inside. Tank or hopper size depends on the load capacity of the aircraft.

Tank Agitation

Many pesticide formulations, such as emulsifiable concentrates, wettable powders, and flowables, require agi

tation of the liquid mixture in the spray tank to maintain uniformity. Without agitation, the pesticide product may

settle out from the water with which

it is mixed. A common method of tank agitation is the recirculation of all or part of the pump output back into the tank (hydraulic agitation). A valve that diverts the flow from the spray boom back into the tank or hopper usually does this. Commonly, this boom valve provides a low negative pressure, or suck-back, to the boom when in the closed position. In another type of agitator, some external source powers a propeller mounted inside the tank (mechanical agitation). Mechanical agitation is not common on aircraft because the power required robs engine performance and adds extra weight. Keep agitators running during ferrying to the worksite and during turnarounds. When the pump has suffi

cient capacity, some of the pump output recirculates back into the tank during spraying as well. Recirculated material

enters near the bottom of the tank to prevent settling of the spray mixture. If you apply dusts or powders, be aware that fine dry materials (60-mesh and above) in the aircraft hopper may also require mechanical agitation to prevent packing or caking on the top surface of the material during flight. This occurrence, known as bridging, creates voids under this top layer and leads to uneven flow of the dry material from the hopper.



### Filters and Screens

Filters and screens protect the dispersal system from damage and keep nozzles from clogging. Clogged filters result in uneven applications. Screens require daily cleaning during spray operations and additional cleaning any time flow volume or change in system pressure indicates clogging. Filter screens range in size from 10 to

200 mesh. A 10-mesh size denotes 10 openings per inch, therefore the larger

the mesh number the finer the screen.

Nozzle Screens Generally, agricultural aircraft do

not use nozzle screens because aerial applications call for larger nozzle orifice sizes than ground applications do. However, certain types of nozzles

and nozzles with smaller orifice sizes require screens or slotted strainers. The nozzle orifice size and the type of liquid you are spraying also determine the size

of the nozzle screen.

Line Screens

When using a centrifugal pump, place a line screen on the output side of the pump, in the line between the pump and the spray boom. For other types of pumps, locate the line screen on the suction side of the pump to help prevent damage from sand or other foreign particles, which can also cause

nozzle check valves to leak. Never store the dispersal system at the end of a season without thoroughly flushing out the booms. This reduces

the likelihood of material accumu

lating on the inside surfaces of booms

downstream from the line screen. This material can flake off later and clog

nozzles or nozzle screens.



### P ipes, Hoses, and Fittings

Main piping and fittings should be of a large diameter (up to 3 inches) to California Agricultural Aircraft Association47 Aeri a l Pesticide D is p ers a l S ystems be able to apply high volumes of liquids. Smaller diameter pipes and fittings (approximately 1 to 1-1⁄2 inch) work for low-volume applications. Smaller piping is compatible with rotary-wing aircraft because their slower speed makes it possible to use lower flow volumes. Whatever the size, piping must be able to handle the maximum pump volume. Hoses used in the dispersal system need to be large enough to carry the

desired flow and must resist corrosion. Hoses are less likely to blow off if ends of the connecting tubes are beaded or flared. Using double clamps on hose connections also helps to keep them secure. Position hoses in such a way as to avoid sharp bends. Replace hoses if they swell, develop surface cracks, or otherwise show wear. Sometimes, hoses may not show external signs of wear or fatigue but they become brittle and hard after extended exposure to sunlight, high temperatures, vibration, and the various pesticides and other chemicals used in the system. Even when they look serviceable, hoses used beyond their life expectancy may fail without warning. Therefore, regularly replace hoses even if they look intact

and free of defects or wear. A positive shut-off valve, installed in the hose or line that delivers spray material to the nozzles, eliminates dripping when you shut off the spray. The most effective positive shut-off valve is one that incorporates a suckback feature so that the pump applies a slight negative pressure to the liquid in the boom. The negative pressure aids the nozzle check valves in preventing any dripping. The system pressure gauge will register this slight negative pressure. If nozzles are not equipped with check valves, you may need to increase the negative pressure. Keep the negative pressure low enough so that it does not remove all the liquid from the spray boom, otherwise there will be too long of a delay as the boom refills when starting a new spray pass.



### Spray Booms

The spray boom is the structure that supports nozzles along the wingspan or rotor span of the aircraft and usually carries liquid spray to the nozzles. It may be round, airfoil shaped, or streamlined. Streamlined

booms create the least amount of tur

bulence, followed by airfoil booms and then round booms. To place nozzles in cleaner airflow on fixed wing aircraft, position the booms behind and below the trailing edge of the wings. For some configurations, use drop pipes from the boom to keep nozzles in clean air. Research shows that this lower position is likely to give a better deposition pattern. Securely attach spray booms to the aircraft to prevent bouncing. Make sure booms are durable enough to Tom Hoffmann—Washington State Department of Agriculture48 C HAP TER 4 handle the output pressure of the pump. Some booms have separate right and left sections. Using a control valve, you can direct spray to either or both of these sections, making it easier to regulate spray placement in sensitive areas. Operators of rotary-wing aircraft sometimes use special boom and nozzle combinations because of their ability to produce large, uniformly sized droplets at slower speeds. Operators use this type of boom most often for applying herbicides to rights-of-ways. Droplets form as the spray exits multiple

needlelike nozzle tubes on the boom. The airstream pulls droplets into the

air behind the boom. Ef fect ive spray booms are approximately 75 percent as long as the wingspan for fixed-wing aircraft

or the diameter of the main rotor blade of rotary-wing aircraft. If booms are longer than this, wing tip or main rotor vortices capture a large amount of the output from nozzles at the boom tips, causing distortions in the spray pattern and contributing to drift.

Position the boom and nozzles so that the spray will not strike any part of

the aircraft or boom attachments. If the spray does strike structural parts of the aircraft, it will likely:

• Collect and fall off in large drops.

• Distort the spray pattern.

• Waste material.

• Corrode aircraft surfaces. Having removable caps on the ends of a boom is useful for periodic flushing of sediment buildup inside the boom. However, a boom with end caps prevents positioning nozzles at or near the boom ends. Trapped pressurized air in this space between the boom

ends and the outermost nozzles causes the spray to continue flowing for a short while even after you close the spray valve. To eliminate this problem,

install air bleed lines to each end of the

boom. Attach the other ends of these

bleed lines to one of the nozzles near the ends of the boom, making sure these nozzles only receive spray fluid

from the bleed lines.



### Flow M eters, Valves, and

P ressure Gauges

The spraying system should include the following components to improve application ability.

Flow Meters

An accurate flow meter monitors the discharge volume of liquid from the pump through the nozzles. The flow meter alerts you to changes in the spraying system such as clogged nozzles, leaks, and pump malfunction.

Valves

Valves in the system start, stop, prevent dripping, and direct and reg

ulate the flow of the liquid. Some valves have control levers that you manually move to turn on or shut off the spray. M. J. Weaver—Virginia Tech H ELIC OP TER S P R A Y BOO M49 Aeri a l Pesticide D is p ers a l S ystems Check valves are spring loaded and have a diaphragm, a ball, or needle and seat that starts or stops the liquid flow depending on whether the pressure in the system exceeds a preset minimum pressure. Electronic flow volume con

trollers employ motorized ball valves to regulate the amount of flow. Inspect valves in the dispersal system frequently to confirm they are working correctly and are not leaking. Sediments or debris in the plumbing of the system may prevent some valves from shutting off completely or may restrict the flow of liquid passing through them.

Make sure all nozzle check valves have the same size outlet diameter to provide uniform flow volumes along the length

of the boom.

Pressure Gauges

Use a pressure gauge as another tool to monitor the spraying system. A pressure gauge helps you determine the correct pump speed or spray valve opening in order to achieve the proper nozzle output, droplet size, and spray pattern. You can use the pressure gauge to monitor and maintain system pressure during application should the electronic flow control system in the aircraft stop working. A pressure change in the system during spraying indicates potential problems. For instance, clogged

nozzles or filter screens could increase pressure. A drop in pressure might indicate a broken nozzle, a disconnected line, another type of leak, or pump malfunction. When a pressure change occurs, inspect the system to determine the cause and make necessary repairs. To assure precise readings of pressure at the nozzles, connect the pressure gauge sensor line to the spray boom. The pressure gauge in the aircraft needs periodic checking. When con

nected to the same pressure source, compare readings from the aircraft’s gauge to another gauge known to be

accurate.



### Nozzles

Nozzles provide the primary means of controlling three factors thataffect any application and possible offtarget movement of the pesticide: the application volume, droplet size, and spray pattern. It is important for nozzles to operate within the range of pressures and flow volumes prescribed by their manufacturers. Therefore, be sure that the spraying system is compatible with the specified pressure and flow volume ranges for the nozzles you use and the aircraft’s speed. Manufacturers produce many types of nozzles for various liquid pesticide application situations. The application volume influences the type of nozzle used in an aerial application. Aerial application volumes fall into three categories:

• Conventional (5 to 15 or more gallons per acre).

• Low volume (LV) (0.5 to 5 gallons per acre).

• Ultra low volume (ULV) (less than 0.5 gallons per acre).

Traditionally, amounts less than 8 gallons per acre were the norm for conventional volume aerial applications. Pilots made these types of applications with cone pattern nozzles. However, aerial spray drift studies indicate that spray output from cone pattern nozzles are likely to emit drift-prone droplets unless configured to produce coarser droplets. Many pilots now make con

ventional applications using straight stream nozzles, variable orifice flood nozzles, or flat fan nozzles. Application volumes in the low volume (LV) range are often suitable

M. J. Weaver—Virginia Tech BOO M

- M OU NTED P RESS U RE GAUG E50 C HAP TER 4 for certain situations, such as applying particular fungicides. You may use flat

fan or variable orifice flood nozzles set to a suitable deflection angle, based on orifice size, pressure, and aircraft speed, for LV applications. Drift studies show that properly installed straight-stream

or variable orifice flood nozzles reduce the amount of small droplets that are prone to drift. When using vegetable oil carriers, or when you apply concentrates in forest or public health pest control, such as mosquito abatement spraying, ULV application volumes may be around one to a few ounces per acre. Rotary atom

izers work well for ULV applications as well as LV applications.

Straight Stream Nozzles

Straight stream nozzles oriented straight back often produce the largest droplets and the lowest drift compared to other nozzle types. These nozzles provide a way to produce large droplets at higher airspeeds when you match

the flow volume of the stream from the nozzle with the airspeed. However, at very high speeds the large droplets produced by straight stream nozzles can

shatter and create driftable fines.

Fan-Pattern Nozzles

Spray drift studies indicate that nozzles that emit fan-shaped spray pat

terns typically produce fewer small,drift-prone spray droplets than do conepattern nozzles. Flat fan and even flat fan nozzle tips produce flat, fan-shaped spray patterns. Flat fan patterns have the highest depo

sition in the center of the pattern and deposition tapers off towards the edges.

Even flat fan nozzle patterns are uniform

across the whole width of the nozzle pattern. The exact angle of the fan-shaped pattern produced by these nozzle tips depends on nozzle design, spray pressure, and

characteristics of the pesticide spray mix.Nozzle tips designed to produce fanshaped patterns have angles of 25, 40, 65, 80, or 110 degrees. In general, fan nozzle tips that produce wide angles generate more drift-prone spray droplets. For this reason, fan nozzle tips designed to emit no more than an 80-degree spray pattern are better suited for aerial spray applications. Typically, 40-degree flat fans are recommended for the higher speeds associated with fixed winged aircraft and 80 degree flat fans are rec

ommended for slower speeds associated with rotary wing aircraft. Compared to standard flat fan nozzles, even flat fan nozzles have little effect on the spray distribution applied by an aircraft. The more critical consideration when using

flat fan nozzles on an aerial boom is that the nozzle tip produces a narrow spray angle.

Variable Flow Rate Flat Fan Nozzles

Typically, nozzle orifice sizes are fixed and the only way to increase

or decrease nozzle flow volume and maintain a desired spray droplet size range at a certain spray pressure is to change the size of the nozzle orifice. With standard nozzles, slightly increasing or decreasing the spray pressure allows minor adjustments in nozzle flow volume, but this adversely affects the optimum spray pattern.

Variable flow rate nozzles overcome this problem because the nozzle orifice size is flexible and enlarges or gets smaller as the system pressure increases or decreases. This maintains greater integrity of the droplet size spectrum and spray pattern as system pressure changes. The advantages of variable

flow rate nozzles include:

• The ability to change application volume on the fly by increasing or decreasing system pressure instead of replacing nozzle orifices.

• Better spray droplet uniformity that is less affected by system pressure changes.

• A more uniform application volume and spray pattern even when application airspeed varies.

Variable Orifice Flood Nozzles

A variable orifice flood nozzle dis

perses liquid in a flood type wide-angle FLAT FAN

NOZZLE EVEN FAN

NOZZLE51 Aeri a l Pesticide D is p ers a l S ystems flat fan pattern or a straight stream. The nozzle body has two manual adjustments, one for orifice size and the other for deflection angle. Four orifices can be selected, plus an “off” position. The orifice size and pressure

determine the nozzle flow volume. Spray from the selected orifice hits an adjustable deflector that you adjust to produce fine, medium, or coarse spray droplets. There are two common types

of variable orifice flood nozzles. One has deflection angles of 30, 55, and 90 degrees and the other has a straight stream setting and deflection angles of 5 and 30 degrees. Slower aircraft typi

cally require larger deflection angles

than faster aircraft.

Rotary Atomizers

A rotary atomizer consists of a screen mesh cylinder that rotates

around the nozzle orifice. Its own fan or an electric or hydraulic motor powers this rotating cylinder. The higher air

speed of fixed-wing aircraft favors the use of fan-driven rotary atomizers. Most fan-drive units have adjustable fan blade pitch so you can achieve the optimum c y l i nder r ot at ion

relative to the aircraft’s speed. The slower speeds of rotary-wing aircraft require motor driven cylinders. Spray droplets that emerge from the screen mesh cylinder are relatively uniform in size. Rotary atomizer

nozzles deliver a wide range of application

volumes. Because they have relatively large metering orifices, their nozzles do not clog as easily as conventional nozzles when applying low-volume sprays containing a high concentration of chemicals in suspension. Uniformity also depends on droplet size and nozzle spacing. The number of nozzles you

need is based on how wide a swath you intend to cover. Typically, a single rotary atomizer can generate a swath of

10 to 15 feet.

Hollow-Cone Pattern Nozzles

Hollow-cone pattern nozzles include the disc-core type and the whirl-chamber type. Recent spray driftresearch indicates that using hollowcone nozzles on an aerial spray boom yields a disproportionate amount of very fine, drift-prone droplets. Because cone nozzles emit spray in a conical pattern, the effect of wind shear is greater than its effect on straight stream or flat fan spray nozzles.

The orifice of a hollow-cone

nozzle is located in a disc that fits into the nozzle body. Discs are available in

various orifice sizes to accommodate application needs. Located behind the disc is a core, or spinner plate, that puts a high rotational spin on the liquid passing through the orifice. The size of

the disc-core combination determines the gallons per minute (gpm) rating of the nozzle at a given pressure.

A whirl chamber nozzle consists of a specialized nozzle body and nozzle cap. When liquid enters the nozzle Glenn Martin—Gettysburg, PA VARIABLE ORIFICE FLOOD NOZZLE

Glenn Martin—Gettysburg, PA52 C HAP TER 4 body, the interior structure causes the liquid to whirl rapidly before exiting as a cone-shaped spray pattern. Whirl chamber nozzles are relatively free from clogging problems.



### Nozzle Anti- D rip D evices

Equip all the nozzles on the spray boom with check valves to prevent dripping when you shut the spray off. These valves have spring-loaded diaphragms, needles, or steel balls that stop the nozzle flow when spray pressure drops below a certain presetamount, usually about 7 psi. Use antidrip check valves in combination with

shut-off valves that have the suck-back feature. In systems where suck-back is unavailable, use a stronger spring so the nozzles seal shut when pressure drops to about 15 psi. Never switch on and off an electric motor driven pump in a rotary-wing aircraft to start or stop spraying. Using the boom valve to start and stop the spray and leavingthe pump running allows the suckback feature to work properly and provides hydraulic agitation for the spray tank. Inspect and frequently clean check valves to assure they work properly and are not leaking. Replace diaphragms when they show wear. You can flush needle and seat types of anti-drip check valves without disassembling the nozzle by pulling on the needle, which typi

cally clears the valve of debris and stops

the leak.



## E lectronic equipment such as global positioning systems, flow volume controllers, and mapping systems are important components of aircraft dispersal systems. This equipment increases precision application, reduces error and drift, and prevents waste of pesticide materials. These systems also provide permanent records of various aspects of the application for site mapping, customer billing, and envi

ronmental and regulatory reporting.



### G P S Systems

Operators choose differential global positioning systems (DGPS) for their aircraft because they provide the high degree of precision needed for aerial application. The amount and kind of navigational information available for aircraft-mounted DGPS equipment depends on the features incorporated into the systems. As with other naviga

tional devices, an FAA-certified aircraft maintenance technician must install, test, and repair DGPS equipment and components. See Appendix 5 for descriptions of types of global posi

tioning systems and how they operate and are managed.

Before purchasing mobile DGPS hardware and software for an appli

HOLLOW CONE SOLID CONE

SPRING LOADED

DIAPHRAGM

NOZZLE FILTER

NOZZLE ORIFICE



### electronics53 Aeri a l Pesticide D is p ers a l S ystems cation aircraft, find out if the equipment processes signals for the type of DGPS

service that is available in the area where the aircraft operates. In addition, learn what kinds of DGPS peripheral devices, such as light bars and flow controllers, the equipment accommodates.

An aircraft fitted with basic DGPS components provides you with the ability to perform DGPS-aided pre

cision aerial swathing. A basic DGPS

includes a:

• DGPS mobile receiver.

• GPS antenna.

• Light bar.

• Computer processor (CPU )—in some units, the CPU and light bar

are combined into one unit.

Using the GPS Light Bar

The GPS light bar is a linear array of light emitting diodes (LEDs) that produce a visual representation of the position of the aircraft in relation to the swath you are spraying. It allows you to easily visualize off-track errors and quickly make flight path corrections.

The onboard DGPS receiver con

tinuously sends about 5 updated signals per second to the light bar. These signals activate specific LEDs, with the center of the light bar indicating the aircraft is lined up with the swath centerline. The other LEDs on the left and right of center represent a certain distance away

from the swath centerline. This distance is usually 2 feet per LED, but can be set to as little as 6 inches per LED. After completing a pass, advance the GPS setting to the next swath. When the aircraft is exactly over the centerline of that swath, the center-most LEDs of the light bar illuminate. If the path of the aircraft shifts to the left of the swath centerline, the illuminated sector of the light bar shifts towards the right. You correct the flight course by steering toward the illuminated LEDs. You restore the correct flight path when only the center most LEDs glow. Once you line up the aircraft with the next swath centerline, use tradi

tional landmark navigation to begin and perform the spray pass by selecting a distant visual object and flying toward it. Occasionally check the light bar during the spray pass to fine-tune your course.



### Computers

The advantages of DGPS computer systems include mapping, waypoint navigation, and spray operation record keeping. The computer provides options for you to select a desired application pattern, such as racetrack. The computer then uses the GPS posi

tioning data to continuously calculate and display the aircraft’s location with respect to the target site and application pattern. This eliminates the need for flagging or marking devices or human flaggers. The computer system records the precise in-field location of each spray swath. For jobs requiring multiple spray loads, its mapping system guides you to where to begin applying the next load. Throughout the spray operation, the computer system collects data and con

structs records.



### Flow Volume Controllers

Manufacturers of DGPS com

puter systems offer software programs and computer hardware interfaces that provide precision spray boom opera

tions. The aircraft DGPS computer combines continuously updated ground speed data with the spray swath width and sends correction signals to the

flow volume controller. The controller regulates boom output by increasing or decreasing pressure and/or flow volume so that it maintains a preset application M. J. Weaver—Virginia Tech GP S INST A LL A TI O N54 C HAP TER 4 volume per acre. More sophisticated units even control output on indi

vidual nozzles. Flow volume controller systems include means for measuring, computing, and recording:

• Total liquid volume.

• Liquid pressure.

• Liquid flow volume.

• Total spray time.

• Relative humidity.

With this equipment, you can deliver the spray uniformly for the duration of the job in progress even when travel speed of the aircraft varies.

You use feedback data from the flow volume controller to construct an on-site record of the output perfor

mance of the spray boom.



### M apping Systems

Producing maps of the targeted area is one of the features of the global posi

tioning systems in many aircraft. These systems enable you to define boundaries, mark hazards, and produce as-applied maps that document your work. These maps are useful references for future applications. In addition, during an application, the on-screen map in the aircraft shows you where you turned the spray on and off. This gives you the accuracy to separate an area of the same field and fly it in a different direction to help you protect sensitive areas.



### p ositioning boo m s an d no zz les



## I mproper positioning of nozzles along the spray boom negates the advantages derived from pilot skill, advanced electronics, other application aids, and modern nozzle engineering and manu

facturing technology. Determining the proper position for each spray nozzle helps achieve uniform spray deposition. Be sure nozzles are in the

aircraft’s laminar airflow where there is undisturbed air. Adjust the spacing of the nozzles along the boom to com

pensate for uneven spray deposition caused by air movement over aircraft surfaces. After positioning the nozzles according to accepted application industry standards, evaluate the setup by conducting pattern testing of the dispersal system. Do this before making any pesticide applications.



### Nozzle Adjustments

There are several factors to consider when adjusting nozzle positions.

Prop Wash Displacement

On fixed-wing aircraft, propeller rotation produces a spiral slipstream about the fuselage. This spiral slipstream moves spray particles from right to left

under the aircraft. The result is a reduced application volume under the right wing and a higher application volume under the left wing. This problem is most evident on aircraft fitted with spray booms that have a symmetrical nozzle arrangement. The conventional cor

rection for prop wash displacement is to add nozzles to the right side of the

boom and remove noz-zles from the left side of the boom. You usually determine

the correct number and location of the nozzles by trial and error, preferably PROP WASH DISPLACEMENT

PROP WASH OVERCOMPENSATION

WING TIP VORTEX55 Aeri a l Pesticide D is p ers a l S ystems while conducting pattern testing, not during pesticide application. Generally,

the nozzles that need alteration are those positioned within 3 to 6 feet of the fuselage.

Prop Wash Overcompensation

The emphasis on spray pattern distortion due to prop wash has prompted some pilots to overcom

pensate for propeller-induced effects. You can often correct a pronounced spray peak developing on the left of the fuselage by turning off one or more

nozzles mounted within 3 to 6 feet of the right side of the fuselage. Conduct pattern testing to assure you have not overcompensated.

Wing Tip and Rotor Vortex

Wing tip and rotor vortexes usually produce spray patterns with high peaks at its edges. This patterncan occur on either fixed- or rotarywing aircraft. The vortex captures and propels upward the spray emitted

from the outermost nozzles on booms that extend to the full wing or rotor span. Spray droplets so captured do

not contribute to the effective swath width, but are a significant source of spray drift. In almost every case, you can overcome a wing tip or rotor vortex induced spray pattern problem by keeping the spray boom length at75 percent of the wingspan for fixedwing aircraft or the rotor diameter of rotary-wing aircraft.

Rotor Distortion

Rotary-wing aircraft may display a spray pattern having a low application

volume in the middle of the swath and heavier patterns at each end of the spray boom. Normally, you can correct this by adding nozzles under the aircraft

between the skids.



### P attern Testing a Spray

Boom

When evaluating the spray pattern and determining the effective swath of an aircraft, the application height, power setting, spray pressure, and nozzle location should duplicate field conditions. The best time for spray pattern testing is early in the morning before the sun heats the ground and

causes thermal turbulence or convective instability. During testing, fly the air

craft directly into the wind. Conduct pattern test flights only when ambient wind speed is less than 10 mph. One method for spray pattern testing consists of a detector (fluo

rometer) that reads the intensity of fluorescent dye deposited onto a string or tape positioned across a test site. A computer converts the fluorescence to data points and displays these in a graphical spray pattern representation. Dale Thomas—Gooding, ID56 C HAP TER 4 Use this graph to assess nozzle posi

tioning along the boom, determine spray deposition uniformity, and

measure the effective swath width. You

need to know the effective swath width to program a DGPS guidance system. If computerized pattern testing equipment is not available, you can determine the spray pattern by other means. The Course Layout figure (next page) depicts a suitable test layout for spray pattern evaluation. Determine the wind direction and place several flags, visible to you from the aircraft, about 100 feet apart along the centerline of the direction of travel. Staple and sequentially number squares of water sensitive paper to small blocks of wood along an 80- to 100-foot line that runs perpendicular to the line of travel. You can substitute plain white cards for the water sensitive paper if you add dye to the spray tank to visualize the droplets. When flying a spray pattern test, make sure that the nozzle tips, filter screens, and check valves are clean. Put about 30 gallons of water into the spray

tank. Before takeoff, operate the pump and briefly engage the boom to check

for leaks. After takeoff, purge the boom and make sure that water from the system reaches the end nozzles. Align the air

craft with the centerline flags on a spray run that duplicates an actual field appli

cation. Operate the boom for at least 100 yards both before and after passing over the line of water sensitive paper or cards. To minimize control surface induced air disturbance, maintain straight and level flight during spray

boom operation—this will help assure a representative pattern. After the pass, have a ground crew member collect the sprayed cards in the order the ground

crew laid them out. Put new cards on the wood blocks and repeat the test to make sure the run was representative of typical spray deposition.

Visual evaluation of treated cards reveals common problems with spray uniformity and swath width. Especially

look for:

• A region of light spray droplet density in the vicinity of the flight

centerline.

• Uneven spray droplet densities toward the wing tips, indicating prop or rotor distortion (see pre

vious section).

• Light spray droplet density cor

responding to boom hangars or other structures that interrupt

airflow.

Correct uneven patterns by repo

sitioning nozzles on the spray boom. Conduct a new pattern test to verify that you have improved the pattern. With a proper nozzle setup, you will notice that the number of spray droplets per card is reasonably con

stant for some distance on each side of the centerline path and then they gradually diminish until no spray is California Agricultural Aircraft Association PA TTERN TESTIN G57 Aeri a l Pesticide D is p ers a l S ystems evident. The typical pattern forms a trapezoidal shape. The effective swath is the distance between the midpoints on the sloping ends of the pattern. Each midpoint corresponds to a spraydeposition that is approximately onehalf the average amount of spray deposited in the more uniform portion of the spray pattern. In an actual appli

cation, this midpoint is the border between adjacent swaths.



### Spraying System
Operating P ressure
Drift reduction requires directing nozzles straight back and setting the spraying system operating pressure to match the speed of the aircraft with the exit speed of the pesticide liquid from the nozzles. A pressure of 40 to 60 psi may produce larger droplets due to less wind shear and minimizes the pro

duction of droplet sizes prone to drift. Drift prone droplets are those that are

smaller than 200 microns in diameter. When it is necessary to increase the output volume of the nozzles, you can make very small changes by increasing or decreasing the system operating pressure, often by changing the pump speed. Electronic spray

volume controllers increase or decrease system pressure to change the output volume of the system when there are slight changes in the aircraft’s speed. This produces an application that is more even than if the pressure remains constant as the aircraft’s speed varies. However, this adjustment has limita

tions because, in order to double the spray output, you must quadruple the spray pressure. This will have a major impact on droplet size. In most cases, the best way to make significant changes in boom output volume is by changing nozzle tip size, nozzle orifice size, or by changing the number of nozzles in use. Typically, you should change the spray system pressure only to make minor changes (alterations of 10 percent or less) in boom output. COURSE LAYOUT FOR PATTERN TESTING

Center line

10 0 Sampling

width Spaced on

2 centers Spaced on

5 centers

Wind

40

Spaced on

5 centers 20



### D R Y M ATERIAL S P REA D ERS



## O n fixed-wing aircraft, ram-air spreaders disperse dry formulations, such as granules or pellets. You would use these spreaders also for applications58 C HAP TER 4 of fertilizers and seeds. On rotary-wing aircraft, you typically use a centrifugal spreader to apply dry formulations.



### Ram-Air Spreader

A fixed-wing aircraft fitted with a properly configured ram-air spreader can apply dry formulation pesticides very uniformly. However, setup and operation may be more complex than that required for applying liquid pes

ticide products. General limitations imposed by ram-air spreaders include higher engine power requirements and high aerodynamic drag, which affect aircraft performance and maneuver

ability. Ram-air spreaders are compara

tively simple, versatile, and reasonably priced. You would typically attach a ram-air spreader beneath the fuselage in such a way that you can remove it easily to restore the liquid spraying capability of the aircraft. The hopper is the same one used to hold liquid pes

ticide sprays. An unsatisfactory distribution pattern of dry materials results from most ram-air devices if you attempt to apply more than 250 pounds per acre

of material or increase the feed rate to more than 35 pounds per second.

Feed Rate

In a ram-air spreader, the dry pes

ticide product drops from the hopper into a ducted airstream, where the airflow ejects it rearward and laterally. A metering gate situated between the hopper floor and the spreader throat governs the feed rate of pesticide granules or pellets. The spreader has either a hinged metering gate or a sliding hatch between the hopper and the spreader. When using a spreader equipped with a hinged metering gate, you use a cable or rod to rotate the trailing margin of the gate downward to open it to whatever setting you want. Material escapes from the hopper by flowing over the lowered edge of the gate. Usually, hinged metering gates require more frequent calibration adjustment than do sliding hatch types. Some hinged metering gate units are capable of dispensing liquid materials. Sliding hatch styles of hopper metering gates generally are easier to adjust, especially for low application rates. However, these units tend to be more prone to wear than hinged metering gates. The hopper metering gate must provide even feed of the pellets or granules across its opening; otherwise, the aircraft will produce an uneven swath pattern. It is unreasonable to expect any combination of ram-air spreader adjustments to compensate entirely for swath pattern problems caused by improper gate adjustment. Substantially increasing the hopper-to-spreader feed rate beyond its design maximum is a poor strategy for increasing application rate. If you meter too much dry pesticide product into the spreader, ducting becomes

choked and less air is able to flow through the unit. Increasing the amount of dry pesticide entering the spreader requires more air to propel the material through the spreader.

Spreader Vanes

The air channel of a typical ram-air spreader consists of from 5 to 13 laterally adjacent, curved ducts. The partitions that form the walls of these ducts are the spreader vanes. Each spreader vane typically has adjustable

sections located at its front and rear. These adjustable sections allow for lateral repositioning of the inlet and exit portions of a given vane within the spreader body. Vane adjustment allows you to fine tune a ram-air spreader to a particular aircraft’s airflow and slip

stream characteristics. In a ram-air spreader, the material metered from the hopper f lowsthrough the ducts as a thin, sheetRAM-AIR SPREADER59 Aeri a l Pesticide D is p ers a l S ystems like layer of particles. Air entering the spreader inlet forces the product rearward, where it flows along the internal upper surface (ceiling) of the spreader. Spreading of this particle layer is the main job of the spreader vanes. When functioning correctly, the vanes prevent air and particles from moving from one duct to another. The top of each vane, including the movable sections, must be in close contact with the top of the internal surface of the spreader. If any air gap occurs between vane and duct ceiling, both air and particles can move from one duct to another during spreader operation. This will seriously affect the even distribution of the pesticide. Adjusting the inlet vane positions helps to make the swath uniform.

Airframe-induced influences are known to affect ram-air spreader performance, but that can often be compensated for by spreader inlet vane adjustment.

• Aircraft oil-cooler-induced

turbulence.

• Speed ring effects.

• Propwash effects.

• Turbulence caused by a flagging

device air deflector.

The propwash effect displaces material released near the right of the fuselage towards the left side of the fuselage. This results in a non-uniform swath where distribution of granules or pellets on the right side is sparse and it is too heavy on the left side. To correct a propwash-induced problem, configure a ram-air spreader to discharge more material from its right side than from its left. Do this by moving the spreader’s inlet vanes toward the left, making the left discharge ports smaller than the right side discharge ports. Shifting inlet vanes too far laterally causes problems, however. As you shift an inlet vane laterally, the airstream attack angle (angle of incidence) of the

duct wall increases. When the duct wall angle of incidence becomes too great, static air pressure increases inside the duct and impairs the hopper-to-duct

flow rate. This causes an undesired reduction of spreader output. Lateral repositioning of an inlet vane should never exceed a 15-degree angle of inci

dence as measured in relation to the path of forward flight. Altering the spreader’s exit con

figuration requires repositioning the adjustable rear portion of one or more spreader vanes if the equipment is set up for this type of adjustment. Rear vane section adjustments provide a way to fine-tune overall swath pattern uni

formity. This is because the position of the rear section of a vane mainly influ

ences the exit direction of the particles passing through that duct. Alignment of the rear section of a vane should, as much as possible, smoothly follow the arc formed by the vane’s rigid internal curvature. For rear vane adjustment, the key con

cepts are smooth, non-obstructive, non-impeding, exit airflow changes. Generally, you only need to make small adjustments. Over-adjustment usually causes particles moving through the duct to slow down, resulting in too much material in one part of the swath.

Spreader Mounting

The best possible mounting config

uration of a ram-air spreader is the one that causes the least turbulence. Having the smoothest airflow into, around, and out of the spreader improves spreader performance and provides good appli

cation results. Relative to an aircraft’s roll axis, a correctly mounted spreader hangs beneath the fuselage and is level with the fuselage from side-to-side and parallel to the long axis of the fuselage. Spreader mounting differs from airframe orien

tation only in pitch. The attack angle of a ram-air spreader directly influences the amount of airflow entering the spreader inlet. Set the spreader attack angle by establishing the pitch of the spreader body during mounting. The forward mounting pointsof ram-air spreaders are usually nonadjustable. Therefore, change the attack angle by changing the distance between the aircraft fuselage and the rear part of the spreader. In general, the lower skin of the spreader is the reference surface for measuring spreader attack angle. The attack angle of the lower surface60 C HAP TER 4 should be approximately 1 to 3 degrees less than the attack angle of the lower surface of the aircraft wing. When a spreader attack angle is either too great or too small, the likely result is:

• Increased turbulence and drag.

• Increased deposition of the pes

ticide material on the tail gear of

the aircraft.

• A non-uniform swath pattern.

• Swath narrowing due to lowered exit speeds of particles.

Application Rate and Swath

Up to the point of its maximum material handling capability, changing the application rate of a spreader auto

matically changes its effective swath width. Increasing hopper feed to the spreader will cause a decrease in swath width because the particle stream exiting a spreader duct becomes heavier and less prone to being broken apart. For high application rates such as jobs requiring more than 250 pounds of pesticide product per acre, the best strategy is to reduce the per-pass appli

cation rate, configure the spreader for a reduced swath width, and fly more passes per site.



### Centrifugal Spreader

The centrifugal spreader used by rotary-wing aircraft is a self-containedunit having its own hopper. The rotarywing aircraft carries the entire unit beneath the aircraft, suspended on a

cable. The unit meters material from the hopper onto a spinning disc that dis

tributes the pesticide, seed, or fertilizer. A hydraulic motor or gasoline engine usually drives the spinner. You control the motor via a hydraulic control cable or by an electrically activated solenoid. Typically, an operation would have two self-contained units so you can spread with one while the ground crew fills

the other. Another method involves using a bag suspended from a boom that the ground crew fills while the pilot makes an application to the field with the spreader. When the hopper needs refilling, the pilot positions the unit under the bag and a ground crew member releases the contents of the bag into the hopper. The refilling operation takes only a matter of seconds while the helicopter hovers above.

USDA ARS Image Library61 Aeri a l Pesticide D is p ers a l S ystems 1. Aircraft suitable for aerial application of pesticides must be:

A. Registered with the U.S. EPA.

B. Constructed entirely of corrosion resistant

materials.

C

. Equipped with DGPS navigational
equipment.

D

. Able to lift, transport, and disperse pesticides safely.

2. One of the reasons for an adequate vent in the aircraft pesticide tank is to:

A. Release excess pressure.

B. Allow the pump to function efficiently.

C

. Prevent a vacuum from altering the normal flow of liquid.

D

. Keep the pesticide mixture uniform.

3. The purpose of baffles inside a liquid spray

tank is to:

A. Assure even mixing of the spray material.

B. Prevent extreme pressure changes in the

system.

C

. Reduce sloshing of the liquid during flight.

D

. Eliminate foaming of the spray mixture.

4. Hydraulic agitation of the mixture in the aircraft spray tank requires:

A. An external power source.

B. Sufficient pump output capacity.

C

. Baffles mounted inside the tank.

D

. Proper tank ventilation. 5. A proper functioning positive cutoff valve with a suck-back feature will supply pressure to the boom and nozzles when the spray flow is stopped.

A. High negative.

B. Low negative.

C

. High positive.

D

. Low positive.

6. The purpose of bleed valves at the ends of the spray boom is to:

A. Prevent spray from continuing to flow from nozzles after the spray valve is closed.

B. Prevent pressure from building up from trapped air when the spray valve is opened.

C

. Make cleaning the inside of the spray boom

easier.

D

. Reduce internal corrosion of the spray

boom.

7. To accommodate for the influence of prop wash on spray pattern, it is necessary to:

A. Regulate the output flow to the nozzles.

B. Adjust the speed of the aircraft.

C

. Reposition the nozzles on the spray boom.

D

. Decrease the pump speed. 

# CHAPTER 4: 

# A eri a l 

# P esticide 

# D is p ers a l 

# S ystems Review Questions62 C HAP TER 4 8. The advantage of an electronic sprayer volume

controller is that it:

A. Maintains the same spray output as airspeed changes.

B. Reduces or increases the spray output as airspeed changes.

C

. Maintains the same spray output as altitude changes.

D

. Reduces or increases the spray output as altitude changes.

9. Ram-air spreaders can:

A. Compromise fixed wing aircraft performance.

B. Improve fixed wing aircraft performance.

C

. Reduce aerodynamic drag on the aircraft.

D

. Reduce the aircraft’s power requirements. 10. The purpose of adjusting ram-air spreader

vanes is to:

A. Improve the performance of the aircraft.

B. Reduce the aerodynamic drag on the

aircraft.

C

. Improve the granule distribution pattern.

D

. Change the swath width of the granule application.

REVIE W QU ESTI O N A NS W ERS O N PAG E 9763 Calibrating A erial A ppli c ation E quipment 

# C alibrating 

# A erial 

# A ppli c ation


# E quipment

P esticide registrants, manufacturers, and regulatory agencies use extensive research to establish proper application volumes and to develop safety pre

cautions that you must legally follow when making a pesticide application. Registrants place this mandatory information on the pesticide labeling. On occasion, regulatory agencies identify a reason to evaluate a product’s existing labeling directions, usually because of human safety concerns. As a result, they may impose regulations that supersede the product’s current labeling. This may involve changing application volumes or imposing addi

tional safety requirements. In order to make a legal, safe, and effective aerial application, you are responsible for applying pesticide products uniformly and at the proper volume per unit of area. Pesticide product labels or local regulations prescribe maximum volumes, so exceeding these volumes violates

federal and state laws. The success of each aerial pesticide application depends on accurate cali

bration. The term calibration refers to setting up and adjusting the application equipment to ensure that you dilute and apply the pesticide active ingredient Reading this chapter will help you understand:

• Why you need to calibrate dispersal equipment.

• How to calibrate liquid and dry dispersal equipment.

• How to make adjustments to the application equipment’s dispersal

volume or rate. 

# CHAPTER 5

LEARNING OBJECTIVES

USDA ARS Image Library C ALIBRATION PRE V ENT S

S ERIOU S PROBLEM S64 CH APTER 5 according to regulations. This chapter discusses the steps to take to calibrate, test, and adjust a fixed- or rotary-wing aircraft’s pesticide dispersal system. Sidebar graphics are included to detail

useful calculations. Once you calibrate the aircraft’s dispersal system, check and test the equipment periodically to be sure the calibration remains accurate. Heavy workloads as well as applying abrasive pesticide formulations contribute to nozzles and other equipment becoming maladjusted or worn. Technological advances such as DGPS systems and electronic controllers make aerial pesticide application more precise. These tools

reduce calibration errors and auto

matically adjust the spraying system to accommodate for changes in pump output, nozzle wear, and variations in application speed. The best resources for setting up and adjusting these systems are their operation manuals. Therefore, this chapter does not cover calibrating or adjusting electronic

devices.



### why y o u nee d to calibrate e qu i pm ent



## T he main reason for calibration is to figure out how much pesticide to put into the tank or hopper of the aircraft so you can apply the work order recom

mended volume to the target site when you operate the aircraft at a deter

mined speed and altitude. Accurate calibration is necessary for:

• Assuring compliance with the requirements in labeling, law, or regulation.

• Effective pest control.

• Protecting human health, the environment, and treated crops or

surfaces.

• Preventing waste of resources.

• Controlling the volume of water (for liquid applications) applied to a given area.



### Improper Application Rate

Applicators are legally liable for injuries or damage caused by improper pesticide application. Several problems are associated with applying a pesticide at a volume higher than the maximum legal rate.

Illegal Residues

Applying higher than legal volumes of a pesticide may result in residues on crop plants that exceed the legal tolerance level. If over-application results in illegal residues on plant sur

faces, regulators have the authority to confiscate and destroy an entire crop

to protect consumers.

Impact on Effective Pest Control

Pesticide registrants and/or manu

facturers of pesticides spend millions of dollars researching ways to use their products correctly and effectively. This research includes determining the right amount of pesticide to apply to control target pests. Using less than the labeled rate is legal, but may result in inade

quate control, wasting time and money. Application volumes that are too low also may lead to problems such as pest resistance and resurgence. Higher than label rates are illegal and waste pesti

cides. Using too much pesticide may adversely affect natural enemies of the pest being controlled.

APHID PEST65 Calibrating A erial A ppli c ation E quipment Human Health Concerns

Pesticides applied at higher than label rates could endanger the health of pesticide handlers, field workers, yourself, and other people working in or visiting an area where you applied them.

Environmental Concerns

Pesticide concentrations higher than label directions may cause serious

environmental problems. Calibrating equipment to maintain application volumes within label requirements reduces the potential for contaminating surface water, ground water, and the air.

Impact on Treated Plant Surfaces

Certain pesticides are phytotoxic (injurious to plants) and damage treated plant surfaces when used at higher than label-prescribed rates. Manufacturers evaluate these potential problems while testing their products so they can

determine safe concentrations.

Soil Contamination

Using too much pesticide increases the chance of building up excessive residues in the soil. A buildup of certain pesticides sometimes seriously limits the types of future crops that farmers can grow in the treated area.

Wasting Resources

Using the improper amount of pes

ticide wastes time and adds unnecessary costs to the application.



### e qu i pm ent calibration m et h o d s



## P esticide materials are expensive, and the fuel, labor, and equipment wear and tear required to make extra applications are costly. If you apply pesticides improperly, you are subject to criminal and civil enforcement actions that may result in loss of your pilot certificate, paying fines and penalties, serving impris

onment time, and the costs and lost time dealing with lawsuits. Properly calibrating aerial appli

cation equipment is necessary to ensure uniform distribution of the pesticide materials and it helps prevent pesticide related problems. The following sections discuss different calibration techniques for liquid application equipment and granular application equipment.



### Calibrating Liquid Sprayers

Calibrating liquid sprayers involves determining how much area each tank of spray covers when the aircraft travels at a known speed and the system operates at a known pressure. You begin by matching the desired application volume and droplet size category with the number of nozzles, nozzle orifice size, application airspeed, and swath width. Use nozzle specifications from

the manufacturer to select nozzles that, as closely as possible, produce the desired spray output and droplet size for the product you intend to apply. Arrange nozzles on the boom in such a way as to produce the desired deposition pattern when applying the material from the application height selected. Keep the application height constant during each swath run to obtain uniform coverage. Avoid adjusting application height to either change the swath width or spray pattern uniformity. Instead, replace

nozzles to correct swath width and pattern uniformity. Once the aircraft is properly set up, measure the following four factors:

• Tank capacity.

• Application airspeed.

• Flow volume.

• Effective spray swath width.

Spray pressure is a component of the flow volume because as the pressure

increases or decreases the flow volume increases or decreases as well. Spray pressure must never exceed the recom

mendations of the nozzle manufacturer.

Check liquid spraying equipment frequently when applying abrasive pesti

cides, such as wettable powders, because these materials cause wear in pumps and nozzles. Pump wear decreases the amount and pressure of fluid output,66 CH APTER 5 while nozzle wear increases the volume of output. Alone or in combination, these two occurrences usually lower the output pressure and may produce a

poor spray pattern.

Tank Capacity

You need to know exactly how much liquid you can put into the air

craft’s spray tank in order to determine how much area you can spray with each load. This requires measuring the capacity of the spray tanks, usually one time only. If you modify the tank, or remove or add components inside the tank, you will have to re-measure its capacity. Never rely on tank size ratings provided by the manufacturer because these may be approximate volumes, they may not take into account fittings installed inside the tank, and they do

not account for the attitude of the air

craft while it is on the ground. Position the fixed- or rotary-wing

aircraft on a level surface and make sure there is no liquid in the system. Drain the system if necessary, then close any open valves to prevent water leaks. Start adding measured amounts of clean water. Keep the pump running to cir

culate the liquid. Using a flow meter, bring the water level to the maximum operating fill point. This is the level to which you will always fill the tank whenever applying a full load. Once you determine the actual capacity of the tank or tanks, paint or engrave this amount onto a prominent place near the tank for permanent reference. While filling the tank, also calibrate the tank sight gauge, or make marks on the tank as you add measured volumes of water. Once you calibrate the sight gauge or tank, it is easy to see how much liquid is in the tank when it is not entirely full. Always return the aircraft to a level surface when reading the sight gauge or tank marks. The sight gauge readings while the aircraft is in flight will differ from readings taken when the aircraft is on the ground due to flight attitude.

Application Airspeed

Measure airspeed under actual working conditions, with the aircraft spray tank about half full of water (to get the best average for weight consid

erations), and flying at the same altitude as an actual spray application. If the air

craft spraying system is equipped with a flow volume controller, the controller will calculate the proper flow volume and make adjustments if airspeed changes. For it to make these adjust

ments, you must enter the application

volume and the size of the effective

swath width into the unit.

Flow Volume

If the aircraft is not equipped with a flow volume controller, measure the actual output of the system when nozzles are new, then periodically

thereafter to accommodate for nozzle wear. Manufacturers provide charts showing the estimated output of given nozzle sizes at specified spray pressures.

Manufacturer charts are most accurate when using new nozzles—used nozzles may have different output volumes

because of wear. Even new nozzles may have slight variations in actual output. Additionally, the pressure gauge in the aircraft may not be accurate, which further adds error to the output estimate

determined from manufacturer charts. These charts express flow volume in gallons per minute, which you can then convert to gallons per linear mile at the prescribed swath width.

R otary-wing A ircraft. Rotary-wing air

craft usually have electric or hydraulic powered pumps, so the aircraft does not need to be in flight to measure nozzle output. To find out the combined flow volume for all nozzles on a helicopter spray boom, collect liquid from each nozzle over a known time (such as 30 seconds) and add together these amounts.

Use a calibrated container that measures liquid ounces. Once you determine the total amount of output, convert the ounce measurement into gallons and then determine the gallons per minute and mile outputs (see Sidebar 1 ).

Fixed-wing A ircraft. Most fixed-wing aircraft use fan driven spray pumps, so

the aircraft must be airborne or have the engine running at high speed while on the ground. Due to the air blast from the propeller, you cannot collect spray from the nozzles. Therefore, find67 Calibrating A erial A ppli c ation E quipment the output of the sprayer over time by measuring how much water you use during several test flights. Each time you fill the tank, make a run operating the sprayer for a timed period. Start by moving the aircraft to a

level surface and fill the tank to a known

amount with clean water. Fill the tank to a level that you can duplicate when refilling. Check for leaks around tank seals, hoses, and hose fittings. Be sure all nozzles are clean and operating properly

or the results will be inaccurate. Take off and fly to an area where you can release the spray water. Operate the sprayer at its normal operating speed and pressure. Open the valve to the spray boom, starting a stopwatch

at the same time. Continue to run the sprayer for several minutes, and then close the valve. Record the elapsed time, return to the ground, and park the aircraft at the same spot where you originally filled the tank.

Attach a flow meter to a lowpressure filling hose and refill the tank to the original level. Record the gallons of water used; this volume is the amount of liquid sprayed during the timed run. Determine the gallons per minute output of the sprayer and convert the result to gallons per mile as shown in

Sidebar 2

. For more accuracy, repeat this process two more times to get an average of sprayer output.

Swath Width

A crucial step in the calibration of an aircraft liquid dispersal system involves determining the effective A helicopter spray boom is equipped with 30 nozzles. Liquid has been col

lected from each nozzle for 30 seconds. When combined, the total amount of liquid collected is 600 ounces.

Convert the 600 ounces per 30 seconds into gallons per minute.

Next, convert the total ounces per minute into gallons per minute.

In this example, the helicopter discharges 9.375 gallons of liquid per minute. This result can be converted to gallons per mile by dividing the airspeed in miles per hour by 60 minutes per hour and then dividing the result into the gallons per minute.

Assume the helicopter is traveling at 50 miles per hour. 

### calc u lating s p ra y er f lo w vol um e p er m ile

( R otary-Wing A ircraft) S i d eb ar 1

= 1200 ounces/minute = ounces/minute total ounces collected × 60 seconds/minute

seconds of collection time

600 ounces collected × 60 seconds/minute

30 seconds

= 9.375 gallons/minute 1200 ounces/minute

128 ounces/gallon

= 0.833 miles/minute 50 MP H

60 minutes/hour

0.833 miles/minute = 11.25 gallons/mile 9.375 gallons/minute68 CH APTER 5 swath width. Although the actual swath width may be wider, the effective swath width includes overlaps made with each pass to achieve a more even application. Measure the amount of overlap leading to the effective swath width produced by an aircraft by pattern testing. Whenever you alter the spray boom in any way or change application height, you must repeat this pattern test and

recalculate the effective swath width. Application height affects the effective spray swath, so the application height used during pattern testing must be the same as the height flown during an actual application.

Application Height

Application height describes the distance between the nozzle tips and the target, be it the plant canopy or open ground at the target site. The effective swath width usually increases as the application height increases due to air movement. However, there are limits to how high you can go and get a wider swath. Spray drift management studies indicate that application height can affect the amount of off-target drift of the spray, depending on the spray droplet size. Therefore, mini

mizing off-target drift risk requires lower application heights. The greater the application height, the more time it takes for spray droplets to reach the target and so they are subjected to evaporation and other forces that create off-target drift. High temperatures and low humidity will increase the evapo

ration rate. An application height of 8 to 10 feet is usually the maximum suitable for applying spray droplets that have

less tendency to drift. For application heights greater than 8 to 10 feet, you need larger spray droplets to reduce drift. The pesticide label usually provides application height limits or a range of application heights for a particular product. Flying too low can cause additional drift issues because of air turbulence hitting the ground (ground effect).

D etermining the Acres per Minute

Treated

To calculate the number of acres treated in one minute, use the airspeed For this example, the aircraft’s spray tank is filled with water to its top mark. After takeoff and leveling off, the pilot made four runs at 120 MPH and opened the spray valve for 30 seconds for each run. After landing, the aircraft was returned to the same location where the tank was originally filled. Using a flow meter attached to a water hose, the tank was refilled to the top mark. It took 36 gallons of water to refill the tank.

Calculate the gallons per minute output of the sprayer.

Convert the gallons per minute into gallons per mile. 

### calc u lating s p ra y er f lo w vol um e p er m ile

(Fixed-Wing A ircraft) S i d e b

ar 2

120 miles/hour

60 minutes/hour = 2 miles/minute

18 gallons/minute

2 miles/minute = 9 gallons/mile = 18 gallons/minute 2 minutes 36 gallons69 Calibrating A erial A ppli c ation E quipment and the effective swath width measure

ments in the calculations shown in

Sidebar 3

.

D etermining the Application Volume per Acre

In the “Flow Volume” section, the fixed-wing aircraft example calculation ( Sidebar 2 ) showed that a boom with 50 nozzles was discharging 18 gallons per minute. At 120 miles per hour, this amounts to 9 gallons per mile. Sidebars

3 and 4 illustrate how to convert the gallons per mile to gallons per acre.

D etermining the Amount of

Pesticide to Put into the Tank

The label or job order prescribes how much pesticide to apply per acre. Be sure to confirm that the job order does not exceed the legal rate given on the label. You may have to adjust nozzle output or modify the appli

cation pattern to achieve this desired

volume. For example, you may have to make more than one pass over a swath to apply the total number of gallons of spray or pounds of granules per acre as required by the label or job order appli

cation rate. To prevent waste of pesticide material, you must accurately know the size of the area to be treated. Then, mix only the amount of pesticide needed. Multiply the total acres in the appli

cation site by the application volume to find out how much pesticide will be required for the complete job. Use tank volume and the gallons per minute figure to calculate how much time it will take for you to spray out all the liquid in the tank. Once you know this time, you can calculate the total

area covered with each tank of material.

The result will be the actual acres of treatment site that you can spray with Convert the airspeed from miles per hour to feet per minute using this formula.

Assume for this example that the aircraft travels at 120 miles per hour. Convert this speed to feet per minute.

Next, multiply the effective spray swath width by the feet per minute airspeed to determine the area, in square feet, covered in one minute. The effective swath width

has been determined to be 50 feet and the travel speed is 10,560 feet per minute.

Convert this area into acres by dividing the square feet/minute by 43,560 square feet/acre. 

### calc u lating acres treate d

p er m in u te S i d e b ar 3

MP H × 5,280 feet/mile

60 minutes/hour = feet/minute

120 MP H × 5,280 feet/mile = 633,600 feet/hour

feet/minute × effective swath width = square feet/minute

10,560 feet/minute × 50 feet = 528,000 square feet/minute 633,600 feet/hour

= 10,560 feet/minute 60 minutes/hour

528,000 square feet/minute

43,560 square feet/acre = 12.1 acres/minute70 CH APTER 5 A spray boom having 50 nozzles discharges 18 gallons of spray per minute. Using the calculations from Sidebar 3 , this aircraft covers 12.1 acres per

minute.

Divide the gallons per minute by the acres per minute to get gallons per acre.

Therefore, the aircraft in this example will be spraying 1.49 gallons of liquid per acre when traveling at 120 miles per hour and spraying a 50 foot

effective swath width. 

### d eter m ining gallons p er acre S i d e b ar 4

18 gallons/minute

12.1 acres/minute = 1.49 gallons/acre

A fixed wing aircraft is equipped a with spray tank with a total measured capacity of 300 gallons. The aircraft spraying system will discharge 18 gallons per minute when flown at 120 miles per hour.

Divide the tank capacity by the gallons per minute to determine how many minutes it will take to spray 300 gallons, the tank’s capacity.

Next, calculate the number of acres that can be sprayed with one tankful of liquid. To do this, multiply the minutes per tank figure by the acres per minute figure computed

in Sidebar 3

.

In this example, the aircraft can treat 201.7 acres with one tank of spray mixture. Assume the job order prescribes 2 pints of pesticide per acre. Knowing that one tank can cover 201.7 acres, the total amount of pesticide to put into the tank can be calculated.

Multiply the pints per acre by the acres per tank and divide this by 8 pints per gallon to determine the gallons of pesticide to put into the tank.

These calculations show that 50.5 gallons of pesticide must be mixed with 249.5 gallons of water to fill the tank with 300 gallons of spray mixture. 

### d eter m ining t h e a m o u nt o f p estici d e

to pu t into t h e tan k S i d e b

ar 5

= 16.7 minutes/tank 300 gallons/tank

18 gallons/minute

16.7 minutes/tank × 12.1 acres/minute = 202 acres/tank

2 pints/acre × 202 acres/tank

8 pints/gallon = 50.5 gallons/tank71 Calibrating A erial A ppli c ation E quipment one tank of pesticide mixture. Knowing

this value and the recommended rate of application (units of pesticide per acre of treatment area) makes it possible to determine how much pesticide to mix

with water in the aircraft’s tank. See

the calculations for this in Sidebar 5

. You also need to calculate the area to be treated (Sidebars 6-9 ).

Changing Sprayer Output

Once calibrated, you have deter

mined the output volume of the aircraft’s spraying system for a specific speed, altitude, and pump pressure. However, there may be times during an operation when you may need to change the output volume slightly. These include:

• Accommodating variations in foliage density. • Different plant spacing within the

same field.

• Special requirements of the

treatment area such as obstacles or

sensitive areas.

• Compensating for nozzle or pump

wear.

You can make the adjustments discussed below, either alone or in combination, to effectively increase or decrease sprayer output, but only within a limited range.

Changing Speed. Typically, you shouldnot adjust application speed in a fixedwing aircraft to change the application volume. However, the simplest way to adjust the volume of spray (and amount of pesticide) you are applying in a

To calculate the area of a rectangular (or square) site, you must know the:

• Length of the longest side (in feet)

• Width of one adjacent side (in feet)

A

rectangular field is 800 feet long and 250 feet wide. To find the area of the field (in square feet), multiply the length times the width.

Convert the 200,000 square feet to acres by dividing by the number of square feet in one acre (43,560 square feet). 

### C alc u lating t h e A rea o f a R ectang u lar

or Squ are App lication S ite S i d e b ar 6

800 feet × 250 feet = 200,000 square feet

200,000 square feet

43,560 square feet per acre = 4.59 acres

lengthwidth72 CH APTER 5 To calculate the area of a triangular site, you must know two dimensions, making sure both of these dimensions are in feet.

•  The length of the longest side of the triangle (its base ).

•  The width of the triangle at its widest point (its height ).

The longest side (base) of a triangular field measures 650 feet. The distance between this side and the point where the two other sides meet (height) is 300 feet.

Divide the 97,500 square feet by 43,560 square feet per acre to find the number of acres in this triangular site. 

### C alc u lating t h e A rea o f a T riang u lar

App lication S ite S i d e b

ar 7

(base × height)

2 area of a triangle =

base 650 feet × 300 feet

2 = 97,500 square feet

97,500 square feet

43,560 square feet per acre = 2.24 acresheight73 Calibrating A erial A ppli c ation E quipment 

### C alc u lating t h e A rea o f a C irc u lar App lication S ite S i d e b ar 8

diameter

radius To calculate the area of a circular site, you must know two values.

•  The radius of the circle in feet (see diagram below)

• The value of the constant pi (often indicated by the Greek letter π ) which is approximately 3.14

The radius is the length of the straight-line distance from the center of a circle to any given place on the circle’s edge. The radius is equal to one half of the diameter. A diameter is the length of the longest possible straight-line distance across a circle, passing through the center of the

circle. Pi is a ratio of the circumference of a circle to its diameter. It is used to determine areas or volumes that involve circles, spheres, and other curved objects.

The area of any circle is determined by multiplying pi ( π ) times the square of the radius of the circle, where the square of the radius means multiplying the length of the radius by itself. Use this formula.

area = π × r 2

where r is the radius and π = 3.14

Before making any calculations, make sure the length of the radius (or the diameter) is known in feet. If only the diameter is known, divide this by 2 to get the radius.

The diameter of the circular field is 400 feet. This means that the radius is 200 feet. To calculate the area, multiply π (3.14) times the square of the radius (200 feet × 200 feet).

area = 3.14 × (200 feet × 200 feet) = 125,600 square feet

To convert this area to acres, divide the 125,600 square feet by 43,560 square feet per acre.

125,600 square feet

43,560 square feet per acre = 2.88 acres74 CH APTER 5 

### C alc u lating t h e A rea o f an

I rreg u larl y-Sh a p e d App lication S ite S i d e b ar 9

Many sites are not perfect circles, rectangles, or triangles. Often, agricultural sites have curved corners, have a bulge along one or more sides, or, have a notched area because an obstacle does not allow cultivation or spraying. This can make an accurate area calculation difficult. Here are some guidelines on how to proceed.

• First, sketch a general map of the site. This is a key step, yet, in most cases, you do not need many measurements to make a good general map. The main purpose of the map is to let you clearly identify the number and kinds of shapes that together make up the site.

• Next, identify the kinds and number of shapes such as triangles, circles, and rectangles that together

form the irregular shape. Return to the field and place marker stakes to identify the boundaries of each identified shape or subsection. Record the location of each marker stake on a map.

• Take in-field measurements to determine the dimensions of each regularly shaped subsection. Record these measurements on the map.

• Calculate the area (in square feet) of each regularly-shaped subsection, following the procedures for calculating the areas of a rectangles, circles, and triangles.

• Finally, add together the square feet calculations from all the subsections. This will give you the total

size, in square feet, of the irregularly shaped site. This square foot measurement can then be converted

to acres.

In the example shown here, based on the general map of the site, three regularly shaped subsections (Triangle A, Triangle B, and Rectangle C) can be identified and measured. Then add together the

three areas.

A B

C75 Calibrating A erial A ppli c ation E quipment rotary-wing aircraft is to change the speed. A slower speed results in more material applied, while increasing the speed reduces the application volume. Changing the travel speed eliminates the need for altering the concen

tration of chemicals in the spray tank if there is a valid reason for increasing or decreasing the application volume. However, there are limits to the amount of speed change that you can make. Increasing speed too much is a problem

because it increases the wind shear effect on spray droplet sizes, producing smaller spray droplets. In addition, faster speeds may reduce the application volume so much that it results in poor coverage and ineffective pest control. Flying too slow may possibly result in over-application by exceeding the maximum label rate. At the very least, it would increase the amount of pesticide applied, causing runoff and waste, and increasing application time and cost.

Changing O utput P ressure. As nozzles begin to wear, the spray volume will increase from the orifice getting larger. However, when a pump begins to wear,

it becomes less efficient as it moves less volume of spray because of the increase in space between the moving parts that normally force the liquid through the system. As a result, the nozzle output drops off. Adjusting the pump speed to increase or decrease output pressure will change the spray volume slightly. Increasing pressure increases the output, while decreasing pressure lowers it. In order to double the output volume, you must increase the pressure by a factor of four. This is usually beyond the capabilities of the spraying system and a pressure increase negatively affects the droplet size spectrum. The working pressure range of the sprayer pump also limits this adjustment.

Changing N ozzle O rifice Size. The most effective way to change the output volume of the aircraft spraying system

is to install different sized orifices on nozzles. Larger orifice sizes increase volume, while smaller ones reduce spray

output. Changing orifice sizes usually alters the pressure of the system and requires an adjustment of the pressure regulator or pump speed. Be aware that changes in orifice size will also change the droplet size and spray pattern and will affect drift potential. A major factor in reducing drift is to reduce the amount of small fines prone to off-target drift. Considerations must include the effect of airspeed on droplet

atomization as well as the effect of air

shear across the nozzle face. Use tables

from nozzle manufacturer web sites or manufacturer literature as guides for estimating output of different nozzle

and orifice size combinations. When you change nozzle orifices, remeasure the output volume.



### Calibrating Granule
Applicators

The techniques for calibrating granule applicators are similar in many ways to those used for liquids. However, granules vary in size and shape from one pesticide to the next, influencing their flow rate from the applicator hopper and spreader. Temperature and humidity may also inf luence granule flow. Due to their lower drift potentials, you generally can apply pesticides formulated as granules from greater application heights than what is suitable for liquids. Usually, higher granule application heights produce more uniform deposition patterns. Before beginning to calibrate a granule applicator, be sure that it is clean and all parts are working properly. Measure three variables when calibrating a granule applicator:

• Application airspeed.

• Output rate.

• Swath width.

Application Airspeed

Always measure airspeed under actual working conditions with the aircraft loaded to normal operational weight and flying at the altitude that you will use when making a granule application.

Output Rate

To determine the rate of output, follow the manufacturer’s guidelines76 CH APTER 5 and set the ram-air spreader gate or centrifugal spreader gate to the desired rate per acre. Place a series of at least 13 collection pans at 5-feet intervals in a straight line on the ground. Set these out perpendicular to the flight line. The footprint shape of the collection pans is unimportant, but the pans should be approximately 4 inches deep and have an area of at least 1 square foot. All of the collection pans must be exactly the same size. Pad the bottom of each pan with a thin foam layer to help prevent any granules from bouncing out.

Swath Width

Fly a swath test along a centerline oriented at a right angle to the line of collection pans. If ambient wind speed is greater than a sustained 8 mph, orient the line of pans at a right angle to the prevailing wind and fly directly

into the wind. After the swath test flight, use a small graduated cylinder to collect and measure granule volume in each individual pan, progressing from left to right. Record each pan’s volume on a graph in the exact order of collection. Plotting these volumes as a graph lets you visualize the distribution of your granule application across the swath. Finally, combine the granules from all the pans into another container, then weigh and record this weight. Calculate the total area of the 13 pans. For example, if each pan is exactly one square foot, the total area would be 13 square feet. Sidebar 10 shows how to calculate the granule application rate

per acre. The distribution shown in the figure on the next page is an idealized plotting of the amounts caught in 13 pans laid out 5-feet apart across a 60-foot swath. Another pass centered 30 feet to the right of the first pass produces a 50% overlap of the swaths

and results in an even distribution of granules. This represents an effective

swath width of 30 feet.

Examination of this figure shows that at point A, six units (these could be pounds, ounces, or any other unit of weight) were collected in the pan. At point B, the first swath applied five units in the pan and the second swath

added one more for a total of six. At point C, each swath applied three units for six units in the pan. The pattern shown at the bottom of the next page is a more typical trap

ezoidal pattern generated by granular spreaders. The effective swath width of a pattern having this shape is deter

mined by adding the distances AD

and BC together and dividing by 2, as shown on the next page. Once you determine the effective swath width, you can estimate the The weight of the granules collected in all 13 pans totals 2 ounces.

Compute the pounds of granules being applied per acre as follows:

Convert ounces per acre to pounds per acre by dividing by 16 ounces per pound: 

### C o mpu ting gran u le a pp lication rate p er acre S i d e b ar 10

43,560 square feet/acre × 2 ounces

13 square feet = 6,701.54 ounces/acre

6,701.54 ounces/acre

16 ounces/pound = 418.85 pounds/acre77 Calibrating A erial A ppli c ation E quipment amount of granules, in pounds per acre. The example above is not an ideal method of calibrating a granule appli

cator because of the large difference in weight between the granules caught in the pans and those deposited onto the actual application swath. Unfortunately, it is often impossible to calibrate dry materials accurately unless you are using the actual materials. Spreading pesticide granules onto an area not des

ignated for the application of a pesticide is dangerous and irresponsible. If pos

sible, obtain blank granules (granules of the same size, shape, and weight as the pesticide product, but without the pesticide active ingredient) from the

manufacturer to use for calibration. If this is not possible, the only alternative is to rely on the equipment manufac

turer recommendations for setting and adjusting the ram-air spreader gate or VOLUME DISTRIBUTION OF GRANULES 60 feet

A B
C

30 feet 7

6

5

4

3

2

1

0

TYPICAL GRANULE APPLICATION PATTERNAPPLICATION RATE

A D C B

If distance AD (the distance between the two end pans containing zero granules) is 60 feet, and distance BC (the distance where granule catch per pan is relatively constant) is 30 feet, calculate the effective swath width.

In this situation, application passes should be made 45 feet apart. 60 feet + 30 feet

2 = 45 feet effective swath width =78 CH APTER 5 centrifugal spreader gate to the desired rate per acre. This setting should result in accurate initial application

rates. You can fine-tune this rate to be even more precise by calculating the amount of pesticide that you applied to a known area and comparing that to

the desired rate.79 Calibrating A erial A ppli c ation E quipment 1. The purpose of calibration is to:

A

. Determine the capacity of the spray tank(s).

B

. Prevent off-target pesticide drift.

C. Apply the correct amount of pesticide.

D. Protect the environment.

2. Applying a pesticide at a rate that is higher than the pesticide label rate is:

A

. Necessary.

B

. Careless.

C. Illegal.

D. Useful.

3. Increasing airspeed without changing the spray output will result in:

A

. More pesticide active ingredient applied

per acre.

B

. Less pesticide active ingredient applied

per acre.

C. An increase in the pesticide flow volume.

D. A decrease in the pesticide flow volume.

4. If 1700 ounces of material is collected from nozzles on a helicopter spray boom in 90 seconds, what is the total flow volume in gallons per minute?

A

. 4.42

B

. 8.85

C. 13.28

D. 17.70 5. An aircraft spraying system has an output volume of 8 gallons per minute. How many gallons are sprayed per mile when the aircraft travels at 130 miles per hour?

A

. 3.7

B

. 4.5

C. 5.8

D. 6.5

6. An effective swath width is the:

A

. Total swath made by two passes.

B

. Total swath made by a single pass.

C. Width of a single pass that includes portions of overlaps from other passes.

D. Distance between the outermost or widest points of application across the entire swath.

7. An aircraft sprays 20.2 gallons per minute. How many minutes of spraying time are needed to spray out 147 gallons of spray mixture?

A

. 6.8

B

. 7.3

C. 8.5

D. 9.0

8. Given an application rate of 11.3 gallons per acre, how many acres can be sprayed with 147 gallons of spray mixture?

A

. 11

B

. 12

C. 13

D. 14 

# CHAPTER 5: 

# C alibrating 

# A erial 

# A ppli c ation



# E quipment Review Questions80 CH APTER 5 9. If an aircraft treats 14 acres per tank of spray mixture, how many pints of pesticide liquid should be put into the spray tank to apply at a volume of 1.5 pints per acre?

A

. 11

B

. 15

C. 21

D. 24 10. How many acres are in a rectangular field that measures 620 feet by 1280 feet?

A

. 16.1

B

. 18.2

C. 22.8

D. 28.8

RE V IE W QUE S TION AN SW ER S ON PAGE 9781 making an aerial pesticide application 

# M aking an 

# A erial 

# P esticide 

# A pp lication

T he reasons for following proper aerial pesticide application methods are to make precise, safe, and legal aerial applications consistently and to minimize the off-target movement of pesticide droplets. Proper application methods include knowing how to:

• Recognize the factors and condi

tions that contribute to off-target pesticide drift and other offsite movement, and know how to minimize off-target pesticide drift

and other offsite movement.

• Safely ferry the aircraft between home base, the loading site, and the application site.

• Inspect the application site and surrounding areas for hazards before beginning the application.

• Watch for hazards throughout the application operation. • Fly an effective application pattern and make safe and efficient turns and passes.

• Recognize the atmospheric factors that influence the stability and maneuverability of the aircraft.

• Use DGPS or other guidance

systems.

Agricultural aircraft are highly visible and noisy, and as a result, some people view aerial pesticide applications as nuisances or hazards. The sight of an aircraft flying low over fields is a serious and sometimes anxiety producing

concern for some. When you make aerial applications, be aware of these concerns and, when necessary, be sure to acknowledge them by taking steps to

foster better communication with the public. Notify people in the area about a planned application and make efforts to mitigate noise in areas where people Reading this chapter will help you understand:

•	 Safe ferrying techniques.

•	 What to check when arriving at the application site.

•	 How to recognize and work with weather at the application site.

•	 Different types of application patterns.

•	 Special considerations when applying granules. 

# CHAPTER 6

LEARNING OBJECTIVES82 C H APTER 6 live and work during ferrying or appli

cation operations. Preflight, departure, and appli

cation checklists are useful tools for you, ground crew members, and others involved in an aerial application operation (see Pages 85 and 86 for pilot and ground crew checklists). These checklists help anyone involved in the operation to organize and manage their responsibilities and they help to assure that the operation is safe and effective.

For you and the ground crew, the first and last runs of the day often call for extra attention. The first flight of the day requires that you and ground crew members be alert and mentally prepared immediately for the complex

ities of the operation—with no time to bring the operation up to maximum performance gradually. Likewise, the last flight of the day must not be rushed or compromised in any way in order to finish quickly—it requires the same attention, care, and time as every other flight during that day. However, the first flight of the day is the best time to schedule jobs that are more difficult since you and the ground crew are

more rested.



## W hen traveling with an empty or full aircraft between the loading area and the application site, fly at an altitude of

at least 500 feet above the surface and keep at least 500 feet away from people or personal property. Make every effort to avoid flying over buildings, residential areas, parks or playgrounds, penned animals, and other areas where people or livestock may be present. If the operation requires many trips back into an area, avoid taking the same

route each time. Instead, vary the flight route by one-eighth to one-fourth mile during each trip to avoid repeated passes over the same surroundings. This tactic tends to minimize the audio and visual impact of the flights, as opposed to repeatedly flying the same route and subjecting the same people to the same

level of distraction. 

### f err y ing

Tom Hoffmann—Washington State Department of Agriculture



### c h ec k ing t h e a pp lication site



## U pon arrival at an application site, fly an initial inspection pass to verify that:

• Local weather conditions are suitable for the prescribed aerial application work.

• Agricultural workers, spectators, trespassers, and others, including their vehicles and equipment, are not within or immediately adjacent to the application area, especially

down-wind of the site.

• Livestock are not in the appli

cation area or adjacent areas where they may come in contact with the spray. • Crops adjacent to the application

site match those identified on the work order—if in doubt, verify the type of crop with the grower before beginning an application.

• All members of the ground crew assigned to this operation are present and ready to begin their

duties.

• The communication link between you, the ground crew, and the base location is functioning cor

rectly and that you have a working backup communication plan in case of equipment failure.83 making an aerial pesticide application • The aircraft DGPS system, if equipped, is properly functioning.

If you note any conditions in the application site or adjacent areas that the pesticide label does not permit or that you consider unsafe, and these condi

tions cannot be resolved quickly, abort the operation and return to your home

base. If the area is clear and conditions favor an application, circle the field at a very low altitude, but high enough to clear all obstructions by at least 50 feet. Look for utility poles, guy wires, high tension power lines and other types of utility lines, and other obstructions such as trees, buildings, windmills, radio antennas, road signs, pipeline markers, and fences that are in or near

the treatment area. Carefully check around trees that may conceal power

lines or other obstacles. Look for breaks in the normal cultivation or planting pattern that may indicate the presence of power lines or other hazards. Poles, high fences, or other obstructions may prevent cultivation of weeds or other vegetative growth in these areas, so look for vegetative clues indicating the presence of obstructions that may oth

erwise blend into the background. After circling the field and noting obvious hazards, fly just above and to one side along power lines and tele

phone wires and check each pole. Look for branch wires, guy wires, and trans

formers. Transformers usually have branch wires leading to a house, shop, well, or other structure. A guy wire will normally be placed on the opposite side of a pole from a branch wire or at the pole where a main line makes a turn. Branch wires may be obscured or dif

ficult to see, so look for a cross arm going in a different direction from the

main wires. If any structures are near the treatment area, look for wires that provide electrical power and telephone

service to them.

Consider the possibility that condi

tions may have changed since someone made previous inspections or aerial applications to this particular field.

For instance, crops in fields adjacent to the application site may be different

from those noted on the work order.

If this is the case, confirm the appli

cation site location. Also, new buildings or wells may have necessitated new power poles, or the utility company may have relocated some power lines.

Sometimes the height of the planted crop or trees may have changed since

a previous application. For example, it may have been possible to fly under certain wires in the spring when a crop was first planted, but not possible later

in the year when the crop is taller. In addition, heat causes wires to expand and therefore hang lower to the ground during hot summer days.



### wh at to w atc h f or du ring an a pp lication



## C onditions at an application site or surrounding areas may change during

the course of an application. For this reason, be constantly alert and keep in contact with someone on the ground at

the site.



### Monitor Changes

Changes that may affect the safety or effectiveness of the opeation include the following:

Weather

Wind speed may increase or decrease or the wind direction may change, creating hazards of drift or

John Mateski—Newberg, OR84 C H APTER 6 contamination of sensitive areas. Alternatively, wind may stop altogether, increasing the chances of a temperature inversion condition. The weather may worsen and turn to rain, requiring postponement or cancellation of

the application. Some pesticides are restricted to applications at times when temperatures remain below a certain level—if the temperature at ground level rises above this point, plants may suffer damage (phytotoxicity) from the

spray material. Certain pesticide labels may have humidity restrictions for application.

Hazards

Previously unidentified hazards may become apparent to either you or the ground crew, requiring that you stop or modify the application at that site. This might include the discovery

of livestock in the area or a work crew arriving to work in an adjacent field or nearby. There may also be communi

cation from the property manager or

others with concerns about hazards.

Field Workers

Field workers may inadvertently walk or drive into an area being sprayed or people working in adjacent fields unaware of the application operation could pass through or walk into the

field under treatment. In both cases, the operation is required to stop until everyone is safely out of the area. This emphasizes the importance and use

fulness of ground crew members in spotting people in the area and helping them to leave quickly.

Service People and Others

Various people occasionally have reasons to enter fields or pass through them as part of their job responsibilities. This includes electric meter readers, delivery services, people called to make repairs on equipment, irrigation district personnel, mosquito control district personnel, and others. In addition, some people enjoy walking or running through rural property, often without the permission of the landowner, and may be unaware of the hazards. The ground crew can assist in spotting and warning anyone attempting to enter the application site and escort them out of the area for their own safety.



### Importance of Onsite

Ground Crew D uring an
Application

Each on-site ground crew member

needs to be able to communicatedirectly with you, providing sitespecific details of current weather conditions, topographical features,location and dimensions of groundbased hazards, buffer zone locations,

and other information about hazards

or sensitive areas. Duties of an on-site ground crew member typically include:

• Acting as a liaison between you and the property manager to ensure aerial application obliga

tions are met. Carol Ramsay—Washington State University85 making an aerial pesticide application 

### P ILOT C H EC K LIST

Things to consider before, during, and after any application.

• Inspect the aircraft and all of its safety equipment and your personal safety equipment for proper operation and usable condition.

• Be sure the aircraft’s onboard fire extinguisher is in working con

dition and has a readable inspection tag.

• Confirm that the correct pesticide material is mixed with the proper

amount of water and put into the aircraft’s spray tank by the ground crew by rechecking the pesticide label and counting the number of empty containers.

• Wear an approved safety helmet, long-sleeved shirt, long pants, shoes, socks, and, when out of the cockpit, the other required personal pro

tective equipment specified on the pesticide label or in regulation.

• If possible, avoid mixing and loading activities to reduce chances of bringing pesticide residue into the aircraft’s cockpit.

• Check the field and surrounding area before applying pesticides to be sure there are no animals, humans, crops, waterways, streams, or ponds that might be injured or contaminated either by direct appli

cation or drift.

• Whenever possible, avoid flying through the suspended spray of a previous pass.

• Stop the application and return at another time if winds rise or other adverse weather conditions develop and create a drift hazard; also stop the application if the wind is too calm, usually less than 2 mph.

• Never turn on dispersal equipment or check the flow volume except while over the area you are treating.

• Refuse to fly if the customer requires having any pesticide applied in a manner and at a time that may create a hazard to crops, humans, animals, and the surrounding environment.

• Make sure every application of a pesticide follows a valid label for a listed crop or site and that the label has no prohibition for application by air.

• Read the label and know the hazardous characteristics of the pesticides.

• Using a smoke generator or other device, estimate how far and in what direction some of the chemical may move away from the appli

cation site.

• Never spray over a flagger, other handlers, or anyone else working in

the area.

• After making an application, if you notice any equipment malfunction or problems, securely fasten a note in the cockpit to alert other pilots

and the maintenance crew.

• Prepare and keep accurate application records.86 C H APTER 6 • Preventing individuals from entering the site, both imme

diately prior to and during the application operation.

• Immediately reporting the presence of unauthorized indi

viduals in the treatment site to you and the on-site field crew supervisor or leader. • Assisting you in pretreatment target area inspection.

• Acting as an in-field reference point for you to identify swath

boundaries.

• Providing emergency response and
summoning emergency services in

case of a crash incident. Instruct members of the ground crew to take several precautions before, during, and after any application.

• Using extreme care when handling pesticides or cleaning the air

craft or other contaminated equipment.

• Reading the labels of all pesticides being mixed and wearing labelor regulation-required work clothing and personal protective equipment.

• Insuring that the correct pesticides are properly diluted and mixed

before loading into the aircraft’s spray tank.

• Tightly securing tanks and hoppers so the pesticides will not blow back over the pilot or the cockpit.

• Closing and securing the hopper and covering it as soon as loading is completed.

• Removing any pesticide spilled around the aircraft tank fill opening.

• Not standing in runoff water and avoiding splashes.

• Changing out of work clothing and washing thoroughly at the end of the work day after handling pesticides, washing the aircraft, or cleaning contaminated equipment.

• Assisting in preparing and keeping application records.

The ground crew should also be familiar with the pilot’s checklist. 

### GRO U N D CRE W C H EC K LIST

A PP LICATION MET H O D S



## U se safe flying procedures during all phases of the application operation.

Never take risks for the thrills at the expense of good judgment or safety. To ensure that the pesticide application will be effective, follow label use direc

tions and requirements in the label and regulations. Avoid off-target pesticide drift or other off-target movement of the pesticide material. Adhere to the methods discussed in this manual to avoid off-target pesticide drift. Visually check the spray or granule discharge while making applications to spot appli

cation problems. Straight, parallel passes produce

the most uniform spray pattern. Use

a reliable method, such as DGPS, to mark each swath to ensure uniform coverage and to avoid excessive overlap87 making an aerial pesticide application or gaps. Whenever possible, make passes perpendicular or at a 45 degree angle to the wind direction to assist in overlap and coverage uniformity. Begin treatments on the downwind

side of the treatment site to minimize flying through spray suspended in the air from previous swaths. Also, try to make application passes parallel to the longest dimension of the treated area

to reduce the number of turnarounds. To prevent spray from contacting sensitive areas, or to avoid flying or turning over residences and other sensitive areas, you may need to wait

for more favorable conditions or alter the application pattern in relation to prevailing wind direction and even

contrary to logical field layout. For instance, consider a rectangular field having its longest width running east

and west. Because the wind is from the north, it would appear logical to make east-west passes. However, on

the eastern border of the field is a road

with houses on the other side of this road. East-west passes require making

turns over the road and houses. In this situation, make shorter, north-south passes over the field—even though this requires making more turns.



### Application Speed

Maintain constant airspeed,

consistent with the calibration of the aircraft, during each pass of an application. Variations in speed during an application may result in uneven coverage unless you are using

an electronic flow volume controller to compensate for speed changes. Flying crosswind or 45 degrees to the crosswind during an application avoids

the adverse effects of head- and tail

winds on the application volume.



### Altitude

Notwithstanding legal require

ments in the label, in law, or in regulation, the type of pesticide you apply usually determines application

altitude. For example, liquid pesticides are most effective and off-target drift is less of a problem when you make appli

cations 8 to 12 feet above the crop or

tree canopy. Flying lower will reduce off target drift because the droplets are closer to the ground, however flying too low may cause uneven streaking due to not allowing enough time for

the spray pattern to fill in. Flying too low over bare ground or over short crops may produce a ground effect that forces air displaced by the aircraft to move upward from the ground.

Ground effect occurs when the aircraft is less than 3⁄4 the wing or rotor span from the ground. This upward moving air entraps and lifts some of the spray and contributes to off-target pesticide movement. Trees and other plants with dense foliage may lower the ground

effect risk. Application altitude also depends

on atmospheric conditions. It is common for an aircraft to fly higher

in calm conditions and lower when the wind is higher. As the aircraft gets lower, the induced drag decreases, reducing drift. Wing tip vortices, which will increase drift, are dependent on aircraft configuration, speed, and weight. Slower and heavier aircraft will have larger wing tip vortices due to increased induced drag. Keep the application height con

stant during each application pass to

maintain the effective swath width that you determined during calibration

of the dispersal equipment. Failure to do so will result in difficulty obtaining uniform coverage.



### Obstructions

If you encounter obstructions at the beginning or end of a swath run, turn the spray on or shut it off one or two swath-widths from the beginning or G R OUND EFFECT

CAUSED B Y FLYING

TOO LOW88 C H APTER 6 end of the field. Then, when you finish all parallel swaths, fly one or two swaths crosswise to the rest of the application

direction to finish out the field. Never disperse materials while dropping in or pulling out of a field because this

distorts the deposition pattern. Should this happen, the pesticide will be more likely to drift or concentrate in a small

area. If there are obstructions along the sides of a field, fly parallel and as close

to the obstruction as is safe. For safety, leave an untreated buffer strip adjacent to buildings, residences, livestock areas, bodies of water, and other sensitive areas.

There are two methods for working around trees, poles, or other

obstructions in the middle of a field.

One is to treat them in the same manner as if they were at the end of the field: stop spraying one or two swath widths before reaching the obstruction. Pull up and fly over the obstruction. Then, make a 180-degree turn before dropping in to spray, approaching the

obstacle from the other direction. This

will allow better control of the aircraft’s speed and will avoid overshooting the

other side. Complete the application by spraying one or two swath widths on each side of the obstacle, perpendicular to the previous swaths. The second method is to stop spraying and pull up as you approach the obstacle, make a 360° turn, fly over the obstacle, drop down, and continue spraying.

When a high enough wire crosses a swath that has trees at one end, fly under the wire if possible, and then pull up and fly over the trees. This is safer than entering the field over trees and then passing under the wire.

RACETRACK PATTERN WIND

DIRECTION

BACK AND FORTH PATTERN 

## O ne flight pattern for aerial application is the adjacent swath or back and forth pattern, applying swaths over the target

in straight, parallel lines. In areas that 

### f lig h t p atterns89 making an aerial pesticide application PROPER TURNAROUND LET

DOWN

LET

DOWN

ANOTHER

METHOD

PULL UP AND LET DOWN TAKES

PLACE INSIDE FIELD TURN IS TOO TIGHT

DOES NOT ALLOW TIME

FOR POSITIONING PULL

UP

PULL

UP

IMPROPER TURNAROUND are too rugged for uniform altitude and speed, follow the contours of the slopes during application passes. In hilly terrain, or where hills or mountains confine the application area and do not permit contour flying, make all passes

in one direction, down slope. Upslope spraying can be dangerous. Usually, the racetrack pattern is the most energy-efficient. This pattern maximizes application time and lessens

the time required for turns. It also allows time for the spray to settle, reducing the chance of flying through it. This pattern often minimizes pilot fatigue. Whether flying a racetrack or back and forth pattern, it is important to start and stop spraying at the right time when entering or leaving the field. Starting too soon or stopping too late causes spray to be applied to off target

areas. Starting too late or stopping too soon may result in improper coverage

to field ends.



### The Turnaround

When flying back and forth or racetrack swaths in a fixed-wing aircraft, be careful when executing turnarounds. This is because a pull up followed by a turn renders a low-speed, high-drag condition that could lead to a stall. Poorly executed turnarounds

cause a considerable number of aerial application accidents. In addition, poorly executed turnarounds do not allow time for proper positioning for the next swath and may result in uneven applications.

When completing a swath run, pull up, clear any obstructions, and level off before starting a turnaround. After pull up, make a wide enough initial turn downwind that will provide sufficient

room for a smooth turn around. Then

level off for several seconds before com

pleting the turn back into the treatment area. This provides ample time for the turn, prevents crowding the turn, and reduces the chance of a stall spin. Many

factors affect the number of seconds needed in level flight before completing the turn, including swath spacing, speed and direction of the wind, air density, altitude, and the load weight, power, and maneuverability of the air

craft. Attentiveness to these factors and careful timing during this final stage of the turnaround are the keys to avoiding

the hazards associated with fast or intricate maneuvering. Always com

plete the turnaround before dropping in over any obstructions on the next swath run approach.90 C H APTER 6 Avoid snapping reversal or wing

over turns. When making a turn by going upwind first requires more space and time to complete the turn. Any turning while dispensing a spray or granules distorts the distribution pattern resulting in uneven application

of the pesticide. Whenever possible, avoid making turnarounds over resi

dences and other buildings, penned poultry or livestock, livestock watering places, ponds, reservoirs, or other bodies of water. Avoiding these areas mitigates or minimizes nuisance from noise or sight of the aircraft.



### Applying Granules

Airspeeds of 100 to 120 mph or faster (depending on the type of air

craft) for some fixed-wing aircraft, but slower for rotary-wing aircraft, are recommended when applying granules. These speeds maintain good airflow through the spreader and obtain proper

distribution and maximum swath width.

Application Height

The maximum swath width at a certain height above the crop varies with the density, size, and grading of

the granule particles. For most mate

rials and aircraft, this is in the range of 45 to 70 feet. Effective height is determined by the lateral distance the spreader throws the heavier particles. Flying below this height allows particles to hit the ground while still traveling in

the lateral direction. Flying above this height achieves no increase in swath width because particles fall vertically after the lateral energy dissipates.

Do not fly any higher than necessary because this increases problems with swath displacement. Maintain the flying height, air

speed, and correct ground track as constant as possible to obtain uniform

results. Crosswinds have considerable effect on offsetting the dispersal pattern from the ground track cen

terline because of the higher-flyingheight required for granules. Heador tailwinds affect ground speed, therefore, making adjustments in flow volume and/or airspeed can improve uniform distribution on alternating upwind-downwind passes. An onboard

DGPS unit linked to a flow controller simplifies this process by providing automatic in-flight regulation of the dispersal system output as airspeed changes. CORRECT APPLICATION HEIGHT APPLICATION IS TOO LOW



### Factors I n f l u encing t h e A ircra f t



## D ensity altitude as well as local weather conditions and load weight can affect the stability and maneuverability of an aircraft during an application operation. Weather conditions such as wind can affect the stability and handling of the

aircraft and contribute to uneven swaths and off-target pesticide drift.91 making an aerial pesticide application T

he following is a fairly accurate and easy-to-remember general rule for determining the density altitude at locations above sea level:

• Standard temperature at sea level is 59oF. For elevations above sea level, subtract 3.5 degrees per thousand feet of elevation from the sea level

temperature of 59oF.

• For each 10oF above standard temperature at any particular elevation,

add 600 feet to the field elevation. For each 10oF below standard tem

perature, subtract 600 feet.

Here is an example. The elevation at the application site is 2,342 feet.

1.  Divide the elevation by 1,000.

2. Multiply 2.342 by 3.5.

3.  Subtract 8.197 from the sea level standard temperature of 59oF.

4. The standard temperature at the application site is 50.8oF. In this example,

assume that the current temperature at the application site is 97oF.

Subtract the standard temperature at the application site from this.

5.  Divide this difference by 10 degrees (for each 10oF above standard).

6. Multiply 4.62 by 600 (600 feet per 10 degrees).

7. Add this correction factor of 2,772 feet to the field elevation of 2,342 feet at the application site.

The density altitude for the application site when the temperature is 97oF is 5,114 feet. This means that you should handle the aircraft at the application site as you would on a standard day at 5,114 feet elevation. 46.2

10 = 4.62 

### ESTIMATING D ENSIT Y ALTIT UD E

2,342 = 2.342 1,000

2.342 × 3.5 = 8.197

59 - 8.197 = 50.803

97 - 50.8 = 46.2

4.62 × 600 = 2,772

2,772 + 2,342 = 5,11492 C H APTER 6 Humidity also affects available engine power and aircraft performance because higher humidity is an increase in water content of air, displacing oxygen that is vital for optimum engine

internal combustion. For example, at 96oF, the water vapor content of the air can be as much as eight times greater

than it is at 42oF. High humidity can reduce the available engine power

needed for takeoff and climbs as well as maneuvers needed for pull-ups and turnarounds during applications.



### D ensity Altitude

Density altitude is a condition where air molecules spread or thin out, becoming less dense, changing aircraft flight characteristics such as lift and maneuverability. In addition, thinner air means that less oxygen is available for optimum engine performance and this reduces horsepower unless the aircraft has a turbocharged engine.

Factors that influence the density of air molecules include pressure (the effect of altitude) and temperature. The higher the altitude, the less dense air

becomes because the air molecules are further apart, leaving fewer molecules

to provide lift for the aircraft. Warmer air temperature also causes air mol

ecules to move further apart, making

the air less dense as well. Density altitude, as well as high air temperatures, affects the stability and maneuverability of the aircraft for making applications, takeoffs, and landings. It also changes stall thresholds and influences the ability to perform

maneuvers such as turns and rolls. The effects of density altitude can even appear in low altitude areas, such as near sea level, when the air temperature

goes above standard (59oF). Takeoff dis

tance, available engine horsepower, and

climb rate are all adversely affected. For an aircraft loaded with spray material or granules, an increase in density altitude

results in:

• Increased takeoff distance.

• Reduced rate of climb.

• Increased true airspeed on approach and landing.

• Increased landing roll distance.

• Limited service ceiling of the air

craft while en route.

Density altitude limits the perfor

mance capabilities of the aircraft, but is not a height reference and should not be confused with pressure altitude, indi

cated altitude, true altitude, or absolute

altitude.

In high elevation areas, usuallybetween mid-morning and midaf ter noon, h igh temperat u re s

sometimes have such an effect on density altitude that normally safe aerial application operations become extremely hazardous. Very high tem

peratures at lower elevations can also affect aircraft performance, making it necessary to reduce the weight of the pesticide load for safer flight. During periods of high temperatures, it may be safer to make applications during early mornings, when temperatures generally are lower. However, early mornings are typical times for temperature inversion conditions in many areas.93 making an aerial pesticide application 

## o ne U.S. Department of Agriculture scientist characterized the growing public

concern over possible effects of spray drift by stating: “Drift control is the key to sur

vival of aerial application in agriculture.”

In response to this concern, members of the National Agricultural Aviation Association (NAAA), the organization of professional aerial applicators and pilots, developed Operation S.A.F.E. The word S.A.F.E., important in any pilot's vocabulary,

is an acronym for Self-Regulating Application and Flight Efficiency.

The intent of Operation S.A.F.E. is to clearly demonstrate that ag aviation recog

nizes its responsibility to minimize the potential for adverse health and environmental effects of agricultural chemical application. The program was approved by the NAAA

Board of Directors in 1981. Because the performance of one aerial applicator reflects on all others, participation

in Operation S.A.F.E. is not limited to NAAA members. Any licensed operator or agri

cultural aviator is welcome to participate in Operation S.A.F.E. In order to qualify for

the S.A.F.E. emblem, the participant must be a current member of the NAAA. Operation S.A.F.E. is a comprehensive program of education, professional analysis of application, and commitment to the principles outlined by the NAAA Board of

Directors. NAAA is convinced that full implementation of Operation S.A.F.E. offers substantial advantages to the operator, customers, and the producers of chemicals applied by air. These advantages are found in economy of operation and application, as well as in increased safety and reduced health and environmental concerns.

The backbone of Operation S.A.F.E. is the Professional Application Analysis

Clinic—the Operation S.A.F.E. Fly-In. Professional application analysis clinics are

a key part of Operation S.A.F.E. Participation in an NAAA-approved swath analysis equipment, under the direction of an authorized analyst, is essential to qualify for the Operation S.A.F.E. emblem. The emblem is affixed to an individual aircraft only when

the aircraft, its pilot, and the operator have each met Operation S.A.F.E. guidelines. Fly-ins have long been a popular activity among pilots. Their objectives tra

ditionally range from getting together to swap experience and stories to socializing. However, among ag pilots, fly-ins have long been seen as a learning experience, an opportunity to improve their own performance and increase their professionalism. The key to the effectiveness— and acceptance—of aerial application is the spray pattern of the aircraft itself and the dedication of operators

to its accuracy. Swath study and analysis have been a part of aerial application since the first plane dusted

an Ohio catalpa grove in 1921. Since that time, scientists from land grant universities and private corporations, and aerial applicators have been active in improving the state-of-the-art of

aerial application. Chemical manu

facturers have worked on chemical 

## Op eration S.A. F .E.

( S elf R egulating A pplication and Flight E fficiency)

Paul Newby —Bozeman, MT (continued on next page)94 C H APTER 6 formulations and additives to improve the pilot's ability to put the product on the target. Today, equipment is available to provide the operator a precise picture of swath characteristics, and to provide it quickly. Thus, the Operation S.A.F.E. fly-in becomes a professional application analysis clinic. The Operation S.A.F.E. clinic gives the operator and pilot the opportunity to test equipment with a trained analyst to help interpret the information and to recommend changes to improve performance. A follow-up test is immediately available, so the operator can be certain improvement does exist. NAAA expects all applicators to remain informed of and comply with all pertinent legal requirements. In addition, participating applicators agree to submit voluntarily to an inspection of their equipment and operating procedures to determine:

• Compliance with manufacturers’ mixing rates, application recommendations, and label requirements of agricultural chemicals.

• Adequacy of safety procedures in storing and handling agricultural chemicals.

• Compliance with flight safety procedures.

The NAAA urges every operator and pilot to participate in an Operation S.A.F.E.

clinic yearly. Check with your state ag aviation association to see when a clinic will be

offered in the area. Display the Operation S.A.F.E. sticker and yearly decals on the air

craft with pride. Let customers know that you have taken advantage of this opportunity to check equipment and refresh your skills prior to taking on their job.95 making an aerial pesticide application 1. The last application flight of the day:

A

. Is more relaxed and requires less attention.

B. Is not as important as other flights of the day.

C

. Requires the same attention as every other flight.

D

. Should be to the most challenging field of

that day’s operation.

2. Varying the application speed without changing flow volume during an application will:

A

. Provide a more even application.

B. Accommodate for wind direction changes.

C

. Result in uneven coverage.

D

. Increase off-target drift potential.

3. The application pattern that helps to avoid flying through spray from a previous swath

is the:

A

. Race track pattern.

B. Back and forth pattern.

C

. Alternate swath pattern.

D

. Upslope pattern.

4. Ferrying flights must be made at an altitude of

at least:

A

. 8 to 10 feet.

B. 100 feet.

C

. 500 feet.

D

. 1500 feet. 5. Ferrying flights that pass over areas where people

live or work should:

A

. Follow the same route in each direction for all trips.

B. Be varied by 1/8 to 1/4 mile for each trip.

C

. Follow the same route each time to the field, but vary the route when returning to base.

D

. Follow a different route each time to the field, but use the same route for each return

to base.

6. Breaks seen in the normal cultivation patterns of a field may alert the pilot to:

A

. Changes in soil type.

B. Problems with field cultivation equipment.

C

. Hidden hazards.

D

. Changes in the needed application volume.

7. Too wide or too narrow overlapping of spray passes will result in:

A

. Flight hazards.

B. Increased chances of off-target drift.

C

. Uneven application patterns.

D

. Disabling of the DGPS system.

8. To avoid the adverse effect of headwinds or tailwinds on an application volume, you should fly:

A

. Into the wind.

B. Against the wind at all times.

C

. Back and forth, alternating between into the wind and against the wind.

D

. Crosswind or 45 degrees to the crosswind. 

# CHAPTER 6: 

# M aking an 

# A erial 

# P esticide 

# A pp lication Review Questions96 C H APTER 6 9. Which of the following would have little effect on the safety and effectiveness of an application if changes occur during the operation?

A

. Moving the operation to a different mixingloading location.

B. Wind intensity increases.

C

. Delaying the application until field workers

leave the area.

D

. Leaving a buffer area adjacent to a sensitive

area. 10. The problem with flying too low when making a granule application is that:

A

. Granules are still moving vertically at lower heights.

B. Granules are still moving horizontally at lower heights.

C

. Even granule dispersal is affected by the ground effect at lower heights.

D

. Propwash has a greater effect on granules at lower heights.

RE V IE W QU ESTION ANS W ERS ON PAGE 9797 Review Question answe r s 

# R eview 

# Q uestion 

# A nswe r s

Chapte r 1 1. b

2. d

3. b

4. a

5. d

6. a

7. c

8. a

9. b

10. c

Chapte r 2 1. a

2. b

3. d

4. c

5. a

6. a

7. c

8. d

9. d

10. c

Chapte r 3 1. c

2. b

3. c

4. a

5. c

6. d

7. b

8. c

9. d

10. c Chapte r 4 1. d

2. c

3. c

4. b

5. c

6. b

7. c

8. b

9. a

10. c

Chapte r 5 1. c

2. c

3. b

4. b

5. a

6. c

7. b

8. c

9. c

10. b

Chapte r 6 1. c

2. c

3. a

4. c

5. b

6. c

7. c

8. d

9. a

10. b98 appendix 1 A labama

Plant Protection and Pesticide Management Section Alabama Department of Agriculture and Industries

P.O. Box 3336 Montgomery, AL 36109-0336
(334) 240-7236

A laska

Environmental Health Alaska Department of Environmental Conservation

555 Cordova Anchorage, AK 99501-2617

(907) 269-1099

A rizona

Environmental Services Division Arizona Department of Agriculture

1688 West Adams Street
Phoenix, AZ 85007-2617

(602) 542-3575

A rkansas

Arkansas State Plant Board

P.O. Box 1069
Little Rock, AR 72203-1069

(501) 225-1598

California

California Department of Pesticide Regulation

1001 I Street

P.O. Box 4015

Sacramento, CA 95812-4015
(916) 445-4000

Canada

Pest Management Regulatory Agency

Health Canada

2720 Riverside Drive D765

Ottawa, ON K1A 0K9

Canada

(613) 736-3662

Colorado

Division of Plant Industry Colorado Department of Agriculture 700 Kipling Street, Suite 4000
Lakewood, CO 80215-8000

(303) 239-4138

Connecticut

Waste Engineering and Enforcement Division Department of Environmental Protection

79 Elm Street
Hartford, CT 06106-5127

(860) 424-3264

D elaware

Delaware Department of Agriculture 2320 South Dupont Highway

Dover, DE 19901-5515
(302) 698-4570 D istrict of Columbia

Department of Health

Environmental Health Administration

Toxic Substance Division Pesticide Program

51 N Street NE, 3rd Floor, Room 3003 Washington, DC 20002

(202) 535-2280

Florida

Department of Agricultural Environmental Services Florida Department of Agriculture and

Consumer Services
3125 Conner Blvd - Suite F, Room 130 - C16

Tallahassee, FL 32399-1650

(850) 488-3731

Georgia

Plant Industry Division Georgia Department of Agriculture
Capitol Square

Atlanta, GA 30334-4201

(404) 656-1265

H awaii

Plant Industry Division Hawaii Department of Agriculture 1428 South King Street

Honolulu, HI 96814-2512

(808) 973-9535

I daho

Division of Agricultural Resources Idaho Department of Agriculture

P.O. Box 790

Boise, ID 83701-0790

(208) 332-8531

I llinois

Bureau of Environmental Programs Illinois Department of Agriculture

P.O. Box 19281 Springfield, IL 62794-9281

(217) 785-2427

I ndiana

Indiana State Chemist Office 175 South University Street Purdue University
West Lafayette, IN 47907-2063

(765) 494-1492

I owa Consumer Protection and Industry Services Division Iowa Department of Agriculture and
Land Stewardship Wallace Building, 502 East 9th Street

Des Moines, IA 50319-0051

(515) 281-8610 

### pesticide regulatory agency

contact information appendix 199 APPENDIX 1 Kansas
Kansas Department of Agriculture

901 South Kansas Avenue Topeka, KS 66612-1281

(785) 296-3556

Kentucky

Division of Consumer and Environmental Protection Kentucky Department of Agriculture
107 Corporate Drive
Frankfort, KY 40601-1108

(502) 573-0282 Louisiana

Pesticide and Environmental Programs Louisiana Department of Agriculture and Forestry

P.O. Box 3596 Baton Rouge, LA 70821-3596

(225) 925-3763

Maine

Board of Pesticides Control Maine Department of Agriculture

28 State House Station
Augusta, ME 04333-0028

(207) 287-2731

Maryland

Office of Plant Industries and Pest Management 50 Harry S. Truman Parkway Annapolis, MD 21401-7080

(410) 841-5870

Massachusetts

Division of Regulatory Services Massachusetts Department of Agricultural

Resources 251 Causeway Street, Suite 500

Boston, MA 02114-0009

(617) 626-1771

Michigan

Pesticide and Plant Pest Management Division Michigan Department of Agriculture

P.O. Box 30017
Lansing, MI 48909-7517

(517) 373-4087

Minnesota

Pesticide and Fertilizer Management Division Minnesota Department of Agriculture

625 Robert Street North
St. Paul, MN 55155-2538

(651) 201-6615

Mississippi

Bureau of Plant Industry Mississippi Department of Agriculture and

Commerce

P.O. Box 5207
Mississippi State, MS 39762-5207

(662) 325-8789

Missouri

Plant Industries Division Missouri Department of Agriculture

P.O. Box 630 Jefferson City, MO 65102-0630

(573) 751-2462 Montana

Agricultural Sciences Division Montana Department of Agriculture

P.O. Box 200201
Helena, MT 59620-0201

(406) 444-2944

N ebraska

Nebraska Department of Agriculture Bureau of Plant Industry

301 Centennial Mall

P.O. Box 94756
Lincoln, NE 68509-4756

(402) 471-2394
N evada

Division of Plant Industry Nevada Department of Agriculture 350 Capital Hill Avenue

Reno, NV 89502-2923

(775) 688-1182

N ew H ampshire

Division of Pesticide Control New Hampshire Department of Agriculture,

Markets, and Food

P.O. Box 2042
Concord, NH 03302-2042

(603) 271-3640

N ew Jersey

Pesticide Control

Coastal and Land Use Enforcement New Jersey Department of Environmental

Protection

P.O. Box 411

Trenton, NJ 08625-0411

(609) 984-2011

N ew Mexico

Division of Agricultural and Environmental Services New Mexico Department of Agriculture
P.O. Box 30005, Department 3AQ

Las Cruces, NM 88003-8005

(505) 646-2133

N ew York

Division of Solid and Hazardous Materials New York State Department of Environmental

Conservation 625 Broadway, 9th Floor Albany, NY 122337250

(518) 402-8651

N orth Carolina

Structural Pest Control and Pesticides Division North Carolina Department of Agriculture and

Consumer Services

1090 Mail Service Center Raleigh, NC 27699-1090

(919) 733-3556

N orth D akota

Plant Industries North Dakota Department of Agriculture

600 East Boulevard, 6th Floor

Bismarck, ND 58505-0020

(701) 328-4756100 APPENDIX 1 O hio

Division of Plant Industry Ohio Department of Agriculture

8995 East Main Street Reynoldsburg, OH 43068-3399
(614) 728-6383

O klahoma

Consumer Protection Services Division Oklahoma Department of Agriculture, Food, and
Forestry

P.O. Box 528804 Oklahoma City, OK 73152-8804
(405) 522-5879

O regon

Pesticides Division Oregon Department of Agriculture 635 Capitol Street, NE
Salem, OR 97301-2532
(503) 986-4635

P ennsylvania

Bureau of Plant Industry Pennsylvania Department of Agriculture

2301 North Cameron Street Harrisburg, PA 17110-9408
(717) 772-5217

P uerto Rico
Analysis and Registration of Agricultural Materials Puerto Rico Department of Agriculture

P.O. Box 10163
Santurce, PR 00908-1163
(787) 796-1710

Rhode I sland

Division of Agriculture and Resource Marketing Rhode Island Department of Environmental
Management

235 Promenade Street
Providence, RI 02908-5767
(401) 222-2782

S outh Carolina

Regulatory and Public Service Programs Clemson University

109 B Barre Hall
Clemson, SC 29634
(864) 656-1234

S outh D akota

Office of Agronomy Division of Agricultural Services South Dakota Department of Agriculture Foss Building, 523 East Capitol

Pierre, SD 57501-3182
(605) 773-4432

T

ennessee Tennessee Department of Agriculture Division of Regulatory Services
P.O. Box 40627, Melrose Station
Nashville, TN 37204-0627
(615) 837-5152 T exas Texas Department of Agriculture Pesticide Programs Division

P.O. Box 12847

Austin, TX 78711-2847

(512) 463-7504

U tah

Utah Department of Agriculture and Food

350 North Redwood Road

P.O. Box 146500 Salt Lake City, UT 84114-6500

(801) 538-7180
V ermont
Vermont Agency of Agriculture, Food, and Markets

116 State Street, Drawer 20 Montpelier, VT 05620-2901

(802) 828-2431

V irgin I slands

Division of Environmental Protection Department of Planning and Natural Resources Cyril E. King Airport
St. Thomas, VI 00802

(340) 774-3320

V irginia

Office of Pesticide Services Virginia Department of Agriculture

and Consumer Services

P.O. Box 1163, 102 Governor Street, Room 149
Richmond, VA 23218-1163

(804) 371-6561

W ashington

Pesticide Management Division Washington Department of Agriculture

P.O. Box 42589 Olympia, WA 98504-2589

(360) 902-2011

W est V irginia

Regulatory and Environmental Affairs Division West Virginia Department of Agriculture

1900 Kanawha Boulevard East
Charleston, WV 25305-0190

(304) 558-2208

W isconsin

Agriculture Resource Management Division Wisconsin Department of Agriculture

Trade and Consumer Protection

P.O. Box 8911
Madison, WI 53708-8911

(608) 224-4567

W yoming

Technical Services Wyoming Department of Agriculture
2219 Carey Avenue Cheyenne, WY 82002-0100

(307) 777-6574101 APPENDIX 2 

### FAA R equirements for A gricultural

A ircraft O perators appendix 2



## T he FAA’s approach for evaluating and determining your ability to comply with Part 137 and other applicable regula

tions focuses on three categories: the pilot, the aircraft, and the operation. You must successfully satisfy each of the following five phases in the evaluation process to become a certified agricul

tural aircraft operator:

• Pre-application.

• Formal application.

• Document compliance.

• Demonstration and inspection.

• Certification.

For complete and helpful infor

mation on the process to follow to obtain an FAA pilot certification for agricul

tural operations, refer to FAA Advisory

Circular 137-1A—Certification Process for Agricultural Aircraft Operators. You may obtain this document and application forms from the local Flight Standards District Office (FSDO). For the nearest FSDO office, check the FAA listing in the United States Government section of the local telephone directory.



### T he P re- A pplication

P rocess
Pre-application involves an informal meeting to provide you with an overview of the certification process and identify the necessary resources helpful to you as you go through the certification process. If you are familiar with all of the requirements of the agri

cultural aircraft operation’s certification process and the required documentation (e.g., if you have previous experience as an agricultural aircraft operator), you may not need a pre-application meeting. During the meeting, an official from the FSDO will determine if you meet the eligibility requirements for obtaining an operator certificate by asking you about the following: • Your area of operation.

• Location of your home base of operations.

• Location of probable satellite sites for your operation.

• Type of operation—private or commercial.

• Your experience with dispensing pesticides or other agricultural

materials.

• Whether you are operating as an individual, a corporation, or a partnership.

• Your previous experience as an agricultural aircraft operator.

• Category and class of aircraft youare operating (rotary- or fixedwing).

• Qualifications and experience of your chief supervisor.

• Applicability of parts 91 and 137 to the proposed type of work.

• Any previous o r pending enforcement action pertaining to you, your management personnel, or chief supervisor.

Depending on the size and scope of your proposed operation, you may need to prepare a letter of intent as part of the required documentation for your application. When required, the letter

of intent must include:

• The specific type of agricultural aircraft operator certificate for which you are applying (com

mercial or private).

• The legal company name of your company and any “doing business

as...” names.

• Address of your home base of operations.

• Primary airport address, mailing address, and telephone numbers.102 APPENDIX 2 • Type of aircraft proposed for the operation.

• The estimated date when opera

tions or services will begin.

• The names and addresses of all management personnel or chief supervisor.

• Names of three people you des

ignate to provide certificate letters, in order of preference.

• A copy of the articles of incor

poration if the operation is a corporation.



### F ormal A pplication

The next step is to fill out and submit three copies of FAA Form 8710-3—Agricultural Aircraft Operator Certificate Application, along with your Letter of Intent (if applicable) and other requested documents to the appropriate FAA Flight Standards District Office. You may obtain this form from the local

FSDO or download it from the FAA web site (http://www.faa.gov) by typing in

“FAA Form 8710-3” in the search box.



### D ocument C ompliance

A certification team assigned to you will review your application and asso

ciated documents within 30 business days of receiving it. They will notify you in writing whether the formal application is accepted or rejected. If the application is inaccurate, not com

pleted properly, or does not include all the required documentation, the team returns the application to you with a letter outlining unsatisfactory items.

You must correct these items before your certification process continues.



### D emonstration and

I nspection

This phase includes inspection of your facilities and aircraft. The team inspects your home base of operations for compliance with applicable operating procedures. The size and complexity of your operation determines the extent of the inspection required at your base. You must demonstrate to inspectors that you can conduct operations to the highest degree of safety. You must provide for inspection at least one certificated and airworthy aircraft that is equipped for aerial agri

cultural work that you will use in your or your employer’s pest control operation. An Airworthiness Inspector verifies that the aircraft is properly certificated and airworthy, its inspection status is current, and it is safe for operation. Inspectors look at five areas during this inspection:

• The commercial applicator record keeping system being used.

• Methods used for informing personnel of their duties and responsibilities.

• Aircraft condition and airworthiness.

• Facilities (if applicable).

• Your knowledge and skills.

If you work as a pilot-in-command for an agricultural operator, then the operator or a person designated by that operator determines your knowledge and skills. Once you successfully dem

onstrate that you have the necessary knowledge and skills, the operator pro

vides you with an endorsement letter.

Application Record Keeping

You must show examples of a record keeping system you have in place for your aerial application oper

ation. The law requires you to keep these operation records for at least 12 months or longer. Since record keeping requirements vary by state, check the requirements in the state where you are conducting business. These records

should include the:

• Name and address of each person for whom agricultural aircraft ser

vices were provided.

• Date of the service.

• Name and quantity of the pes

ticides and other agricultural material dispensed for each oper

ation conducted.

• Name, address, and certificate number of each pilot used in agri

cultural aircraft operations and the103 APPENDIX 2 date that pilot met the knowledge and skills requirements of 14 CFR § 137.19(e).

• Additional information depending on state requirements.

Informing Personnel of Their Duties and Responsibilities

You must provide inspectors with documentation that shows how you have informed each person employed in your agricultural aircraft operation of their duties and responsibilities for the operation. The EPA Worker Protection Standard mandate for documenting pesticide handler training in agricul

tural operations satisfies some of these requirements.

Aircraft

A n A irworthiness Inspector inspects the aircraft, aircraft records, and dispensing equipment. The inspector verifies the following to

determine the aircraft is safe to conduct the proposed operation:

• You have up-to-date and complete

aircraft maintenance records.

• The aircraft complies with all applicable airworthiness direc

tives.

• The aircraft meets certification and airworthiness requirements.

• The aircraft inspection is up-todate.

• The aircraft has approved and properly labeled seat belts and

shoulder harnesses installed for each pilot station.

• The aircraft is appropriately equipped for agricultural opera

tions.

• If the aircraft is equipped to release the tank or hopper as a unit, it is equipped to prevent inadvertent release by the pilot or other crew

member.

• The aircraft is in a condition for safe operation.

Should questions arise concerning the load jettisoning capability of the aircraft used in congested-area opera

tions, you must present jettisoning test data that show the aircraft is equipped with a device capable of jettisoning at

least one-half of the aircraft’s maximum authorized load of agricultural materials within 45 seconds. Jettisoning does not apply to rotary-wing aircraft.

Facilities

FAA regulations do not specify the type of facilities you must have as an agricultural operator. State and local regulations and, to some extent, EPA regulations address requirements for facilities. The FAA facilities inspection verifies that the practices and proce

dures at the base of operations conform to FAA regulations.

Knowledge Test

The Operations Inspector con

ducts a knowledge and skills test during initial certification. As required by § 137.19(e), you or your designated chief supervisor will be the testing candidate. This requirement applies to applicants who seek either a private or a com

mercial operating certificate. The objective of the knowledge and skills test is to evaluate the pilots in an operation and to assure that they are qualified to act as pilot-in-command of an agricultural aircraft. A pilot who was previously qualified under part 137 may not have to take the knowledge and skills test if proper documentation is

available. The pilot must have adequate knowledge of the aircraft’s operating limitations to be used under the appli

cable requirements contained in 14 CFR part 91, § 91.9. Weight and balance information receives special emphasis. Knowledge of the aircraft’s perfor

mance capability is required and

includes:

• Stall speeds at maximum certifi

cated gross weight, straight ahead, power off, and flaps up.

• Best rate and best angle of climb speed.

• Maneuvering speeds.

• Density altitude and its effect on performance.104 APPENDIX 2 • Performance capabilities and oper

ating limitations of the aircraft to

be used.

• Takeoff distance required to clear

a 50-foot obstacle at maximum certificated gross weight with zero

wind.

In addition, you must demonstrate your knowledge of the following limi

tations and restrictions applicable to agricultural aircraft operations:

• Passenger carrying.

• Weight and balance.

• Operating without position lights.

• Dispensing in congested areas.

• Not observing standard airport traffic patterns.

• Altitude during ferrying to and from dispensing sites.

Before an applicator credential is awarded for dispensing pesticides, you must demonstrate a thorough knowledge of methods to protect a pilot against contamination and methods of safe pesticide use and handling. The knowledge test may be written or given orally, and consists of the following subject areas:

• Steps to take before starting operations, including surveying

the area to be treated.

• Handling pesticides and proper disposal of used containers.

• Pesticide hazards and precautions when handling and applying pesticides.

• Recognizing symptoms of pesticide exposure, appropriate first aid, and how to contact a poison control

center.

• Safe flight and application proce

dures.

• State-specific laws and regulations. Skills Test

You perform the skills test with the aircraft’s tanks or hoppers loaded, using a suitable inert material such as water, lime, or sand. The examiner evaluates your piloting skills and operational judgment in the following areas:

• Ground crew coordination and loading procedures.

• Engine start, warm-up, and taxi procedures.

• Fixed-wing aircraft short-field and soft-field takeoffs, directional control, liftoff, and climb.

• Approaches to the working area.

• Flareout.

• Swath runs.

• Pull ups and turnarounds.

• Clean-up swath or trim passes.

• Jettisoning of remainder of load

after swath runs in the event of in-flight emergency.

• Rotary-wing aircraft rapid deceleration or quick stops.

• A pproach, touchdow n, a nd directional control on landing.

• Taxi, engine shutdown, and securing of aircraft.



### C ertification

The FA A awards you t he Agricultural A ircraft Operator’s

Certificate after the FSDO certifi

cation team concludes that you meet the qualifications listed above and you demonstrated that you have the nec

essary knowledge and skills or have a knowledge and skills endorsement from the operator of the firm for whom you are working.105 APPENDIX 3 

## H eat stress occurs when the body is subjected to a level of heat with which it cannot cope. With heat stress, the heat, not pesticide exposure, causes certain symptoms. Wearing personal protective equipment—clothing and devices that protect the body from contact with pesticides—can increase the risk of heat stress by limiting the body’s ability to

cool down.

Avoiding Heat Stress

Several factors work together to cause heat stress. Before beginning a pesticide-handling task, think about whether any of the following conditions are likely to be a problem that might

lead to heat stress:

• Heat fac tors— temperat u re, humidity, air movement, and sunlight.

• Workload—the amount of effort

a task takes.

• Personal protective equipment (PPE).

• Drinking water intake.

• Scheduling.

Heat and Workload

High temperatures, high humidity, and sunlight increase the likelihood of heat stress, although air movement from wind or from fans may provide cooling. Because hard work causes the body to produce heat, a person is more likely to develop heat stress while working on foot than while driving a vehicle. Lifting or carrying heavy containers or equipment also increases the likelihood of overheating.

Signs and Symptoms of Heat Stress

Heat stress, even in mild forms, makes a person feel ill and impairs his or her ability to do a good job. They may get tired quickly, feel weak, be less alert, and be less able to use good judgment. Severe heat stress (heat stroke) is a serious illness. Unless you cool a heat stress victim quickly, he or she can die.

Severe heat stress is fatal to more than 10 percent of its victims, even young, healthy adults. Victims may remain sen

sitive to heat for months and be unable to return to the same type of work. Learn the signs and symptoms of

heat stress and take immediate action to cool yourself or another person down if these symptoms appear. Signs and symptoms may include:

• Fatigue (exhaustion, muscle weakness).

• Headache, nausea, and chills.

• Dizziness and fainting.

• Loss of coordination.

• Severe thirst and dry mouth.

• Altered behavior (confusion, slurred speech, quarrelsome or irrational attitude).

Heat cramps are another type of heat stress. These are painful muscle spasms in the legs, arms, or stomach caused by loss of body salts through heavy sweating. To relieve cramps, drink cool water. Stretching or kneading the muscles may temporarily relieve the cramps. If there is a chancethat stomach cramps are pesticiderelated rather than caused from salt loss, get medical help right away.

First Aid for Heat Stress

It is not always easy to tell the dif

ference between heat stress illness and pesticide poisoning because many signs and symptoms are similar. Get medical help right away rather than wasting time trying to decide what is causing

the illness. First aid for heat stress

includes:

• Get the victim into a shaded or cool area. 

### H EAT stress appendix 3106 APPENDIX 3 • Cool the victim as rapidly as pos

sible by sponging or splashing the skin, especially around the face, neck, hands, and forearms, with cool water or, when possible, immersing in cool water.

• Carefully remove all PPE and any other clothing that may be making

the victim hot. • If conscious, have the victim drink as much cool water as possible.

• Keep the victim quiet until help

arrives.

Severe heat stress (heat stroke) is a medical emergency. Unless you cool the victim immediately, brain damage and death may result.107 APPENDIX 4 

### S teps to F ollow in C leaning U p

a P esticide S pill appendix 4



## T he following steps should be taken whenever a pesticide spill takes place. For large spills, contact local authorities for assistance in management, pre

vention of injuries, and protection of

the environment.

• Refer to the pesticide label to determine the PPE required for cleaning up a spill.

• Clear the area and keep unpro

tected people from coming near the spill.

• Administer first aid and obtain medical care for anyone who received, or possibly received, a pesticide exposure.

• Prevent fires by extinguishing sources of ignition and providing adequate ventilation.

• Control the release. Use any strtegy available to stop the flow of the spill.

• Contain the release. Use sand or other absorbent to keep the pes

ticide confined. Patch the leaking

container or transfer its contents

to a sound container.

• Clean up the spilled pesticide and absorbent and any contaminated objects. Place these materials into a sealable and suitable holding

container.

• Clearly label containers holding spilled pesticide and contaminated soil and other objects. Include the pesticide name, signal word, and name of responsible party.

• Manage the contaminated area. Consult the product label and Material Safet y Data Sheet (MSDS) for the particular product. Consult with the state regulatory agency on how to properly manage the release and how to properly dispose of recovered product and

other items such as contaminated

soil and absorbents.108 APPENDIX 5 

### GLO B AL POSITIONING SYSTEMS appendix 5



## A global positioning system (GPS) pro

vides one of the most accurate meth-ods of navigation for aerial pesticide applica

tions. A receiver installed in the aircraft picks up satellite signals that let you know the speed of the aircraft, direction of travel, and its altitude and location.

Because of the usefulness of this infor

mation, GPS equipment, in most cases, is an essential tool for precision aerial application. Recent studies indicate that at least 92 percent of agricultural pilots in the U.S. use GPS equipment.

A GPS receiver uses satellitetransmitted data to calculate its own

current location. In order to find its exact location, the receiver must simul

taneously detect identification signals

from four different GPS satellites. The time it takes signals to travel from three

of the GPS satellites form the basis for the calculations performed by the GPS

receiver to determine its three-dimen

sional spatial location. Signals from the fourth satellite verify time signals from

the three other satellites. The U.S. Department of Defense created the Global Positioning System program in 1973. The original intent ofthis program was to provide a satellitebased navigational system for military purposes. Although various aspects of GPS technology are now readily acces

sible to the public, the U.S. Department

of Defense continues to fund and manage the GPS program. The Global Positioning System can rapidly reference any specific location on Earth. Functionally, the GPS system consists of three major components or

segments:

• Space Segment—a constellation of 24 Earth-orbiting satellites.

• Control Segment—five Earthbased satellite monitoring stations.

• User Segment—individual GPS signal receivers owned and operated by users. Space Segment

The Department of Defense began launching Earth-orbiting GPS satel

lites in February 1989 and completed this task in June 1993 with 24 satel

lites in orbit. Each satellite completes one orbit around the Earth every 12 hours, remaining in one of six orbital paths. Relative to the Earth’s surface, the six orbital paths are equidistantly spaced at 60-degree intervals and each orbital path is inclined approximately 55 degrees relative to the Earth’s equa

torial plane. This satellite arrangement

enables a GPS user to access between five and eight satellites at any one time.

Control Segment

The control segment consists of five Earth-based tracking stations. Stations are located in Hawaii, on

Ascension Island in the middle of the South Atlantic Ocean, on the island of Diego Garcia in the middle of the Indian Ocean, on Kwajalein Atoll (2,100 miles southwest of Hawaii and 1,400 miles east of Guam) in the Pacific Ocean, and in Colorado Springs, Colorado. The Colorado Springs location is the master station. All the tracking

stations monitor the satellites and determine precise orbit location data. The Colorado Springs master station

sends corrections for orbital location

and clock data to all satellites in the system. This information enables a satellite to send an up-to-date subset

of satellite location and time data to a

user’s GPS receiver.

User Segment

The user segment is the worldwide total of all GPS receivers currently in service. This includes government, military, and civilian users. Seagoing vessels, trains, trucks, mass transit busses, cars, farm equipment, motor

cycles, commercial airliners, general aviation aircraft, and agricultural air

-109 APPENDIX 5 craft use GPS signals for navigation. In addition, GPS units provide useful data for many purposes other than navi

gation, such as:

• A universal and instantly available global time reference having atomic clock accuracy.

• A basis for precision map con

struction.

• A way to precisely measure move

ments of geological formations.

• The ability to track all of the indi

vidual vehicles within an entire fleet, such as with taxicabs or fire

trucks.

• The guidance needed for an air

craft to execute an accurate and safe landing under local zero vis

ibility conditions.

• The ability to provide aircraft speed and location in real time for agricultural aircraft to automati

cally and continuously regulate spray output as a function of the actual travel speed and position of

the aircraft.

Differential GPS

Each GPS satellite broadcasts signals over two microwave frequency channels. One channel carries a strong signal that only the military uses. The signal of the second channel, known as the coarse acquisition (C/A) signal, is less robust. This signal is available for nonmilitary GPS use, although calculations based on it do not provide pinpoint precision of the GPS receiver location. C/A signals typically provide location precision in a range of ± 100 feet horizontal accuracy. This level of precision is not accurate enough for aerial pesticide application. To improve accuracy of the C/A signal, a technology known as Differential GPS (DGPS) provides greater precision. DGPS technology with a strong differential correction signal reduces the horizontal error range down to between less than three feet and rarely more than ten feet. Aerial applicators use DGPS systems. Regular GPS relies on a single receiver, but DGPS technology requires

two. One receiver remains fixed at an accurately surveyed location, and serves as a reference point. Aircraft have the

second receivers installed in them. Both

of these receivers detect the same C/Asignals from orbiting satellites, but the stationary receiver transmits data to refine the mobile receiver’s positioning information. Although the stationary receiver cannot determine which par

ticular GPS satellites a mobile receiver uses, it detects all accessible satellites, computes the timing signal correction factor for each, and transmits the cor

rection data to the aircraft’s mobile receiver, which sorts out the satellite

data. DGPS providers transmit the cor

rection signals from stationary GPS

receivers to mobile receivers over a widerange communication network. Two transmission methods predominate:

• FM radio tower beacon (e.g., U.S.

Coast Guard Differential GPS Navigation Service; Nationwide Differential GPS Service).

• Communication satellite relay (e.g., Wide Area Augmentation System (WAAS) and various commercial DGPS services).

Wide Area Augmentation System

Because GPS alone did not meet navigation requirements of the Federal Aviation Administration for accuracy, integrity, and availability, the FAA and the Department of Transportation (DOT) developed the Wide Area Augmentation System (WAAS) for use in precision flight approaches. WAAS corrects for GPS signal errors caused by ionospheric disturbances, timing, and satellite orbit errors, and it provides vital integrity information regarding

the status of each GPS satellite. WAAS consists of approximately 25 ground reference stations positioned across the United States, covering a very large service area. These stations link together and form the U.S. WAAS network. Two master stations, one

located on the East Coast and the other on the West Coast, collect data from

the reference stations and create a cor

rection message that they transmit to a110 APPENDIX 5 geostationary communication satellite (GEO). The satellite broadcasts the message on the same GPS frequency

to receivers onboard aircraft that are within the broadcast coverage area of

the WAAS. The WAAS improves basic GPS accuracy to approximately 28 feet ver

tically and horizontally, improves the availability of the signals using geo

stationary communication satellites, and provides necessary integrity infor

mation about the entire GPS system. For some users in the U.S., the position of the geostationary satellites over the equator makes it difficult to receive their signals if trees or moun

tains obstruct the view of the southern horizon. WAAS signal reception is ideal for open land areas and for marine applications.

U.S. Coast Guard Maritime Differential GPS Navigation Service

The U.S. Coast Guard provides

a Maritime DGPS service for the Harbor and Harbor Approach phase of marine navigation. The Maritime DGPS service coverage area includes the coastal United States, Great Lakes, Puerto Rico, and most of Alaska and

Hawaii. It consists of two DGPS control

centers and about 65 DGPS reference

stations. The reference stations transmit correction signals on U.S. Coast Guard radio beacon frequencies, and this service is available to the public. Many GPS receivers are equipped with built-in radio receivers that accept and process GPS-satellite correction signal data. The position accuracy of

the Maritime DGPS Service is within approximately 33 feet. If an aircraft is equipped with suitable DGPS receiving equipment, and is less than 100 miles from a reference station, its pilot may typically expect positioning accuracy of about 2.5 feet. For aircraft operating more than 100 miles away from the Maritime DGPS reference station, positioning accuracy decays at a rate of approximately 3 feet per 90 miles. Because of this distance-related decay in accuracy, you should obtain GPS sat

ellite signal corrections from the closest

Maritime DGPS reference station for the most accurate positioning data. The Nationwide DGPS program is incor

porating the Maritime DGPS program into its system.

Nationwide DGPS Service

A 1997 federal law directed the U.S. Department of Transportation to work with several other government entities to develop and operate a standardized Nationwide DGPS Service. The goal ofthis service is to provide reliable localarea GPS-satellite signal correction data to the public without charge. This program involves the U.S. Air Force, U.S. Coast Guard, U.S. Army Corps of Engineers, the National Oceanic and Atmospheric Administration, the Federal Highway Administration, and the Federal

Railroad Administration. When com

pleted, the Nationwide DGPS Service expects to have approximately 80 DGPS radio beacon sites in place throughout the continental United States. The plan will provide every area in the continental United States with double coverage

DGPS correction data from two landbased radio beacon towers. The program will ultimately include all U.S. Coast Guard-operated DGPS reference sta

tions. Each Nationwide DGPS System

radio beacon site has a 300-foot tower antenna that substantially increases the effective range available for mobile DGPS user reception. The signal from each site covers a range of 250 miles with enough signal strength to provide posi

tional accuracy of about 3 feet or less.

Commercial DGPS Services

Commercial DGPS ser vices provide additional options for pilots making aerial applications in remote

locations. These services fill in areas missed by the government systems. Most mobile DGPS equipment is com

patible with the commercial DGPS services. Subscribing to one of these services provides pilots with a high degree of location accuracy suitable for precise aerial pesticide application.111 GL OSSA RY adjuvant. A material added to a pesticide mixture to improve or alter the deposi

tion, toxic effects, mixing ability, per

sistence, or other qualities of the active ingredient.

agitation device (agitator). A mechanical or hydraulic device that stirs the liquid in a spray tank to prevent the mixture from separating or settling.

agricultural aircraft operations. The Fed

eral Aviation Administration Regulation Part 137 of the Code of Federal Regula

tions Title 14 (14 CFR 137) prescribes rules governing agricultural aircraft op

erations within the United States and the requirements for commercial and private Agricultural Aircraft Operator certificates for those operations.

agricultural aircraft operator certificate. Certificate issued by the Federal Avia

tion Administration under provision of 14 CFR 137 to pilots who meet specific requirements as provided in Part 137.

anti-drip device. A spring-loaded mecha

nism built into an aircraft spray nozzle

that closes off the nozzle when the fluid pressure drops below a certain level. This prevents nozzles from dripping when the spray is shut off.

application pattern. The course the pilot follows above the area being treated with a pesticide. See also back and forth
application pattern and racetrack ap

plication pattern

.
application swath. See swath and swath

width

.

area of a circle.

Area = 3.14 × radius × radius (A = π r 2 )

area of a square or rectangle. Area = length × width area of a triangle. Area = base × height divided by 2

back and forth application pattern. Also known as a back and forth flight pattern. Making application swaths in a sequential manner by flying a swath in one direction and the adjacent swath in the opposite direction.

baffle. A structure built into an aircraftmounted spray tank that suppresses the sloshing of liquid in the tank, reducing the

effect of load shift on the aircraft.

boom. A structure attached to an aircraft to which spray nozzles are attached.

buffer area (or zone). A part of a pestinfested area that is not treated with a pesticide to protect adjoining areas from pesticide hazards.

buffer strip. An area of a field left unsprayed for protecting nearby structures or sen

sitive areas from drift. The minimum buffer strip is usually one swath width.

carrier. The liquid or powdered inert sub

stance that is combined with the active ingredient in a pesticide formulation. May also apply to the water, oil, or other substance that a pesticide is mixed with prior to application.

Code of Federal Regulations (CFR). Regu

lations used to enforce federal laws. The

CFR contain sections that address aerial application of pesticides as well as training and certification of pesticide handlers.

co-distillation. A phenomenon where pes

ticide molecules are picked up in water vapor and can move off site.

Commercial A gricultural A ircraft O perator. A category of the FAA certification pro

cess applying to pilots for hire who make pesticide applications by air. 

# G loss ar y112 GL OSSA RY commercial applicator. A person who, for hire, uses or supervises the use of a restricted-use pesticide and this defini

tion varies among states.

conflict with labeling. Any deviation from instructions, requirements, or prohibitions of pesticide product label

ing concerning storage, handling, or use, except: a decrease in dosage rate per unit
treated; a decrease in the concentration of the mixture applied; application at a frequency less than specified; use to con

trol a target pest not listed, provided the application is to a commodity/site that is listed and the use of the product against an unnamed pest is not expressly prohib

ited; employing a method of application not expressly prohibited, provided other directions are followed; mixing with an

other pesticide or with a fertilizer, unless such mixing is expressly prohibited; and

an increase in the concentration of the mixture applied.

congested area. A populated area where personal injury or property damage might occur if an aircraft crashes or if the pesticide load must be dumped.

conventional application volume. For aircraft, the conventional application volume ranges between 5 to 15 or more gallons of spray per acre.

corrosive materials. Certain chemicals

that react with metals or other materials. Some pesticides are corrosive, and special handling requirements are needed when using these.

coverage

. The degree to which a pesticide is distributed over a target surface.

decontaminate. The most important step in reducing potential injury when someone has been exposed to a pesticide. Decontamination involves thoroughly washing the exposed skin with soap and water or flushing the exposed eye with a gentle stream of running water.

dehydration. The process of a plant or animal losing water or drying up. De

hydration is a major contributor to heat related illnesses in people.

density altitude. A condition where air mol

ecules spread out or become less dense as altitude increases and/or as temperatures rise. Density altitude has an effect on the operational performance of an aircraft. differential G PS ( D G PS ). A global position

ing navigation system that relies on a mo

bile receiver mounted in an aircraft and a fixed ground-based receiver, providing a higher degree of positional accuracy than

a mobile receiver used alone.

directions for use. T he instructions found on pesticide labels indicating the proper procedures for mixing and application.

drift (spray)

. (from National Coalition on Drift Minimization) “The movement of pesticide through the air at the time of pesticide application or soon thereafterfrom the target site to any non- or offtarget site, excluding pesticide move

ments by erosion, migration, volatil

ity, or windblown soil particles after application.”

driftable fine. S pray droplets that are 200

microns in diameter or smaller.

droplet spectra. A classification of spray droplets into eight categories based on the volume median diameters of spray droplets. The eight categories are extra fine, very fine, fine, medium, coarse, very
coarse, extra coarse, and ultra coarse.

dynamic surface tension. V ariation or changes in the surface tension of a liq

uid based on the position of molecules of substances within droplets that alter

surface tension.

economic poison. (1) Any substance or mixture of substances intended for pre

venting, destroying, repelling, or miti

gating any insects, rodents, nematodes, fungi, weeds, and other forms of plant or animal life or viruses, except viruses on or in people or other animals, which the Secretary of Agriculture shall declare to be a pest, and (2) any substance or mix

ture of substances intended for use as a plant regulator, defoliant, or desiccant.

effective swath width. A swath that in

cludes overlaps made with each pass to achieve a more even application.

environmental contamination

. Spread of pesticides away from the application site into the environment, usually with the potential for causing harm to organisms.

evaporate. The process of a liquid turning
into a gas or vapor.113 GL OSSA RY exposure. The unwanted contact with pes

ticides or pesticide residues by people, other organisms, or the environment.

extensional viscosity. The amount of stretching or stringiness required for a droplet to break off from a stream or flow of liquid.

Federal A viation A dministration (F AA ). The federal agency responsible for en

forcing rules affecting aircraft operations.

ferrying. The process of flying an aircraft from its home base to a pesticide applica

tion site and returning to its home base or location where the material loading takes place.

field worker. Any person who, for any kind of compensation, performs cultural ac

tivities in a field. A field worker does not include individuals performing tasks as a crop advisor, including field checking or scouting, making observations of the well being of the plants, or taking sam

ples, nor does it include local, state, or federal officials performing inspection, sampling, or other similar official duties.

filter screen. Fine screens placed in key locations in a spraying system to catch foreign materials that would otherwise clog the spray nozzles.

fine. A spray droplet that is 200 microns in

diameter or smaller.

first aid. The immediate assistance provided to someone who has received an expo

sure to a pesticide. First aid for pesticide exposure usually involves removal of contaminated clothing and washing the affected area of the body to remove as much of the pesticide material as pos

sible. First aid is not a substitute for competent medical treatment.

flow rate. The amount of pesticide being expelled by a pesticide spray or granule applicator per unit of time.

general-use pesticide. Pesticides that have been designed for use by the general public as well as by licensed or certified applicators. General-use pesticides usu

ally have minimal hazards and do not require a permit for purchase or use.

geostationary communication satellite. A satellite whose orbit speed exactly
matches the rotation of the earth, and thus remains stationary in relation to
the earth; used for communication and global positioning.

global positioning system. A navigation

al device that uses signals from satellites to determine the receiver’s position.

granule

. A dry formulation of pesticide ac

tive ingredient and inert materials com

pressed into small, pebble-like shapes.

handle

. Mixing, loading, transferring, applying (including chemigation), or assisting with the application (includ

ing flagging) of pesticides; maintaining, servicing, repairing, cleaning, or han

dling equipment used in these activities that may contain residues; working with opened (including emptied but not rinsed) containers of pesticides; adjust

ing, repairing, or removing treatment site coverings; incorporating (mechani

cal or watered-in) pesticides into the soil; entering a treated area during any application or before the inhala

tion exposure level listed on pesticide product labeling has been reached or greenhouse ventilation criteria have been met; performing the duties of a crop advisor, including field checking or scouting, making observations of the well being of the plants, or taking samples during an application or any restricted entry interval listed on pesti

cide product labeling. Handle does not
include local, state, or federal officials performing inspection, sampling, or

other similar official duties.

handler. A person involved with mixing, loading, transferring, applying (includ

ing chemigation), or assisting with the application (including flagging) of pesticides; maintaining, servicing, repairing, cleaning, or handling equip

ment used in these activities that may contain residues; working with opened (including emptied but not rinsed) containers of pesticides; adjusting,
repairing, or removing treatment site coverings; incorporating (mechanical or watered-in) pesticides into the soil; entering a treated area during any appli

cation or before the inhalation exposure level listed on pesticide product label

ing has been reached or greenhouse
ventilation criteria have been met; and114 GL OSSA RY performing the duties of a crop advisor, including field checking or scouting, making observations of the well being of the plants, or taking samples during an application or any restricted entry interval listed on pesticide product la

beling. The handler definition does not
include local, state, or federal officials performing inspection, sampling, or

other similar official duties.

heat-related illness. Potentially lifethreatening overheating of the body un

der working conditions that lack proper preventive measures, such as drinking plenty of water, taking frequent breaks in the shade to cool down, and removing or loosening personal protective equipment during breaks.

human flagger. An individual who assists in an aerial application by positioning and waving marking flags to indicate to the pilot the location of swaths. Flaggers must receive pesticide handler training.

intentional misapplication. The deliber

ate improper use of a pesticide, such as exceeding the label rate or applying the

material to a site not listed on the label.

inversion. A weather phenomenon in which cool air near the ground is trapped by a layer of warmer air above. Vapors of pesticides applied during an inversion can become trapped and concentrated and move away from the treatment area with the potential to cause damage or injury at some other location.

labeling. The pesticide product label and all other written, printed, or graphic matter accompanying the pesticide. Labeling may not necessarily be attached to or part of the container.

light bar. An accessory to the aircraft mounted global position system that enables the pilot to locate the center of each spray swath through the use of an array of lights.

low volume (L V ) application volume.

A pplication of liquid pesticides at the rate of 0.5 to 5 gallons of liquid per acre.

Material S afety D ata S heet (M SDS ). A n information sheet provided by a pesti

cide manufacturer describing chemical qualities, hazards, safety precautions, and emergency procedures to be followed in case of a spill, fire, or other emergency.

mesh. T he number of wires per inch in a

screen, such as a screen used to filter foreign particles out of spray solutions to keep nozzles from becoming clogged.

Mesh is also used to describe the size of pesticide granules, pellets, and dusts.

micron. A very small unit of measure:

1 / 1,000,000 of a meter; represented by the greek symbol μ.

M SDS

. S ee material safety data sheet

.
non-target organis m. A nimals or plants
within a pesticide-treated area that are not intended to be controlled by the
pesticide application.

off-target pesticide drift. Pesticide drift
that moves outside of the application area during or immediately following a
pesticide application.

off-target pesticide movement. A ny movement of a pesticide from the loca

tion where it was applied. Off-target movement occurs through drift, volatil

ization, percolation, water runoff, crop harvest, blowing dust, and by being car

ried away on organisms or equipment.

output volume. The amount of a pesticide mixture discharged by an aircraft over a measure period of time. The usual out

put volume for aircraft liquid sprayers is measure in gallons per minute or gallons per mile.

pattern testing. The process used to determine the spray swath or granule swath pattern by flying test passes and visualizing the droplet array or granule

distribution across the swath.

personal protective equipment ( PPE ). Apparel and devices worn to minimize human body contact with pesticides or pesticide residues. PPE must be provided by an employer and is separate from, or in addition to, work clothing. PPE may

include chemical resistant suits, chemi

cal resistant gloves, chemical resistant footwear, respiratory protection devices, chemical resistant aprons, chemical re

sistant headgear, protective eye wear, or a coverall (one- or two-piece garment).115 GL OSSA RY pesticide drift. Any movement of pesticide

material from its intended swath dur

ing application. Movement of pesticide material becomes problematic when it moves from the application site.

pesticide handler. S ee handler

. phytotoxic. Injurious to plants.

pilot-in-command. The Journeymen Pest Control Aircraft Pilot supervising or conducting a pesticide application.

precautionary statement. The section on pesticide labels where human and envi

ronmental hazards are listed; personal
protective equipment requirements are

listed here as well as first aid instructions and information for physicians.

private agricultural aircraft operator. A category of the FAA certification process applying to pilots who make pesticide applications by air on their own property or property of which they

control.

private applicator

. An individual who uses or supervises the use of a pesticide for the purpose of producing an agricultural commodity on property owned, leased, or rented by him or her or his or her employer.

prop wash

. The displacement of air and spray droplets caused by the propel

ler of the aircraft. The spray pattern is displaced to the left of the centerline of

the aircraft.

racetrack application pattern. The ap

plication pattern that involves making successive overlapping loops across a field rather than a back and forth pattern.

regulations

. The guidelines or working rules that a regulatory agency uses to carry out and enforce laws.

residual effectiveness. The pesticidal ac

tion of material after it has been applied. Most pesticide compounds will remain

active several hours to several weeks or even months after being applied.

restricted-entry interval (R EI )

. The pe

riod of time after a field is treated with a pesticide during which restrictions on entry are in effect to protect people from potential exposure to hazardous levels of

residues. restricted-use pesticide

. Highly hazardous pesticides that can only be possessed or used by certified commercial or private applicators.

rotor distortion. Similar to prop wash of a fixed wing aircraft, but involving the displacement of air and entrapped spray droplets as a result of the rotation of the rotary wing aircraft rotor.

service container. Any container designed to hold concentrate or diluted pesticide mixtures, including the sprayer tank, but not the original pesticide container.

shear viscosity. The resistance of a liquid

to flow.

smoke generator. A device mounted on an aircraft that produces smoke by injecting oil into the exhaust system. This smoke trail is used by the pilot to visualize air

movement.

statement of practical treatment. A sec

tion of the pesticide label that provides information on treating people who have been exposed to the pesticide. This in

cludes emergency first aid information.

supplemental label

. Additional instruc

tions and information not found on the pesticide label because the label is too small but legally considered to be part of the pesticide labeling.

swath (or swath width)

. The area covered by one pass of the pesticide application
equipment.

temperature inversion. See inversion

.
ultra low volume ( U L V ) application

volume. Applications of less than 0.5 gallons of spray per acre.

volume median diameter ( V M D ). Half of the total spray volume of a nozzle consists of spray droplets that are smaller than the
VMD numerical value, while the other half is made up of droplets that are larger

than the VMD numerical value.

wide area augmentation system ( WAAS ). A highly accurate GPS navigational sys

tem used for precision flight positional

determination.

wing tip vortex. The circular or spiral swirling of air caused by the wing tips of an aircraft, and resulting in entrapment of spray droplets affecting the dispersal116 C HAPTE R 7 pattern. Keeping the fixed wing aircraft boom length at approximately 75 per

centage of the wingspan eliminates spray droplets becoming entrapped.

W orker P rotection S tandard. The 1992
amendment to the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) that makes significant changes to pesti

cide labeling and mandates specific train

ing of pesticide handlers and workers in production agriculture, commercial greenhouses and nurseries, and forests.117 INDEX 

# A

access, unauthorized 11, 17, 18, 19, 21, 31, 84

acres per minute treated, determining 68, 69, 70,

additional labeling 12, 13

additional restrictions

pesticide label 12, 13, 22, 24, 25-26

on application 13, 22, 26, 84

adjacent

crops 25, 30, 82, 83, 84

fields 25

non-target areas 24, 25, 82, 84

swath 57, 88

adjuvant 28, 36-37, 40

drift control 37, 40

aerial application

equipment, calibrating 12, 40, 58, 63-78, 87

equipment, cleaning 26-27

operation security, evaluating 18

making 81-93, 95

aerial pest control operator 1, 9-13, 25

laws and regulations for 93, 94

aerial pesticide applicator pilot 1, 9

detailed content outline for 3-5

laws and regulations for 9-13

agitation 44, 45, 46, 52

hydraulic 46, 52

mechanical 46

tank 46

agricultural aircraft operation 101-104

FAA requirements for 10, 29, 101-104

operator certificate 101, 104

air shear 39, 40, 51, 57, 75

aircraft

crash, plans and emergency response in case of 29

factors influencing 90-92

features and limitations of 23-24 securing 18

airspeed, application 24, 27, 39-40, 47-51, 65, 69,

71-75, 87, 92

alcohol and drugs, avoiding use of 18, 21-22
using before or during operation 22

altitude

application 10, 64, 66, 71, 75, 83, 87

ferrying 82

A merican S ociety of A gricultural and B iological

E ngineers 36, 37

amount of pesticide to put into the tank,

determining 64, 69-71

answers, review questions 96

antenna, G PS 53

anti-drip device nozzle 45, 52

application

airspeed 24, 27, 39-40, 47-51, 65-69, 71, 75, 87, 92

altitude 10, 64, 66, 71, 75, 83, 87

avoiding obstructions during 83, 87-88, 89

documenting 27-28, 54

equipment, aerial, calibrating 12, 40, 58, 63-78, 87

equipment malfunction 23, 29, 48, 49

equipment, types of 12, 43-62
height 22, 24, 28, 38, 40, 65, 68, 75, 87, 90

instructions 11, 12-13, 26

low volume 45, 47, 49-50, 51

pattern, back and forth 88-89

pattern, racetrack 88-89

pattern, turnaround 89-90
reviewing and documenting 27-28

safety 22-28
site, adjacent crops 25, 30, 82, 83, 84

site, checking 19, 25, 26, 82-83

speed 24, 27, 28, 39-40, 43, 44, 47-51, 54, 57, 64,

65-69, 71, 75, 87, 88, 89, 90, 92

speed, changing 71-75

swath 28, 40, 45, 51, 53, 55, 56, 57, 58, 59, 60, 65,

66, 67-68, 70, 75, 76-77 

# I ndex118 INDEX techniques 12, 40

volume 44, 49, 50, 51, 54, 55, 63, 64, 65, 66, 69,

71, 75, 87

what to watch for during 83-86

applying granules 57-59, 69, 75-78, 81, 86, 90, 92

area of a circle, calculating 73

area of a rectangle, calculating 71

area of a square, calculating 71

area of a triangle, calculating 72

ASABE 13, 36, 37

ASABE S -572.1 13, 36, 37

as-applied map 28, 54

associated labeling 12

atomization 39, 44, 75

avoiding heat stress 22, 105

avoiding obstructions during application 83, 87-88,

89

avoiding use of alcohol and drugs 21



# B

back and forth application pattern 88, 89

baffle 45

boom, spray 47-48, 49, 51, 52, 53, 54-56

length of 24-25, 39, 49, 55

booms and nozzles, positioning 54-57

buffer area or zone 13, 22, 26, 40, 84, 88

buffer strip 88



# C

calculating area of

a circular application site 73

a rectangular or square application site 71

a triangular application site 72

an irregularly-shaped application site 74

calibrate equipment, why needed 64-65

calibrating

aerial application equipment 63-78

granule applicators 75-78

liquid spraying equipment 65-75

calibration

methods, equipment 65-78

reasons for 64-65

capacity, spray tank 65-66, 70

carrier, pesticide spray 37, 38, 50

catastrophic event 29 categories, standard droplet size 13, 35, 36, 37,

38, 39

centrifugal

spray pump 45, 46

spreader 58, 60

certificate, agricultural aircraft operator 65,

101-103

certification, pesticide applicator 1, 2, 10-12, 27

certified commercial applicators, general

standards for 11-12

changing

application speed 71

nozzle orifice size 75

output pressure 75

sprayer output 71

check valve 29, 45, 46, 47, 49, 52, 56

checking the application site 82-83

checklist

ground crew 86

pilot 85

Class II Medical Certificate 10

classification of droplet size 35-37

cleanup

kit, spill 28, 29, 107

pesticide spill 20, 107

clothing and equipment, protective 11

Code of Federal Regulations 10, 12

co-distillation 38

commercial

agricultural aircraft operator 10, 101

applicator 1, 11

DGPS services 110

pesticide applicator pilots 1

communication 18, 24, 27, 30, 81, 82, 84

communication satellite, geostationary 110

compatibility 26

competency, determination of 11

components, liquid dispersal system 44-57

conflict with labeling 27

conflicts, resolving 27

congested area 23, 103, 104

contact information, pesticide regulatory agency

98-100

container, service 10

contamination, environmental 29, 30

content outline, detailed 3-8

controller, flow volume 49, 52, 53, 54, 57, 66, 67

conventional application volume 49119 INDEX corrosive pesticide materials 44

coverage, pesticide 24, 36, 39, 40, 45, 65, 75, 86,

87, 89

crash, aircraft, plans in case of 29

crops adjacent to the application site 25, 30, 82,

83, 84

cultural practices 25, 27



# D

decontaminate 44

dehydration, preventing 22

density altitude 89-92

detailed content outline 3-8

determination of competency 10, 11

determining

acres per minute treated 68, 69
amount of pesticide to put into the tank 69, 70

application volume per acre 69, 70

D G PS 52, 53, 56, 64, 81, 83, 86, 90, 108, 110

service, commercial 110

differential global positioning systems 52, 109,

110, 112

differential G PS 52, 53, 56, 64, 81, 83, 86, 90, 108-110

diluting pesticide concentrates, knowing

procedures for 12

dispersal

equipment 23, 43-60

system requirements 43-60

displacement, prop wash 54, 55

distortion, rotor 55, 56

documenting

application 27-28, 54

handler training 103

drift 12, 13, 20, 23, 24, 25, 29, 33-40
control adjuvant 37, 40

factors that contribute to 34-39
minimizing off target 13, 24, 33-40, 75, 81, 86, 87

driftable fine 34, 35, 50

droplet

size and drift, external factors affecting 37

size categories, standard 37

size, classification of 35-37

size, effects of evaporation on 37-38

spectra 13, 35-37, 112

spectra, nozzle classification by 36-37

drugs, avoiding use of 18, 21-22

dry material spreaders 57-60

dynamic surface tension 36 

# E

economic poison 10

effective swath width 28, 40, 45, 51, 53, 55, 56, 57, 58,

59, 60, 65, 66, 67-68, 70, 75, 76-77

effects of evaporation on droplet size 37-38

electronics 49, 52-54, 57

emergencies

ground crew 28-29
planning for 28-30

emergency

information 28

maneuvers 23, 24

response plan 28-30

employee

habits 19, 21-22

training 19-21

endangered species area protection map 12

environmental

concerns 65

contamination 29, 30

fate of pesticides 11

E nvironmental P rotection A gency 10
registration number 27, 28

requirements for certification 10-12

environmentally sensitive areas 25, 26

equipment

calibration methods 63-78

securing 17-19

estimating density altitude 89-92

evaporate 35, 37-38

extensional viscosity 36

external factors affecting droplet size

and drift 37-39



# F

F AA requirements for agricultural aircraft

operators 101

facilities, securing 18

factors

influencing the aircraft 90-92
contributing to drift 34-39

fan-driven pump 44, 45, 51, 66

fan-pattern nozzles 40, 49, 50

F BI 18, 19

features and limitations of the aircraft 23-24

Federal A viation A dministration 10, 29, 52, 101120 INDEX federal aviation regulations 10, 29, 52, 101

Federal B ureau of I nvestigation 18, 19

feed rate, granule spreader 58, 60

ferrying 10, 28, 46, 81, 82

filter screen 46, 49, 56

filters and screens 46, 49, 51, 56

fines (pesticide droplet) 35, 50, 75

first aid 11, 18, 20, 24, 26, 29

and decontamination requirements 18, 20, 26

for heat stress 20, 21, 22, 113

measures 26

first and last runs of the day 82

flagger, human 29, 40, 53, 85

flight hazards 25, 28, 29, 54, 81, 83

flight pattern 24, 28, 29, 53, 58, 81, 87, 88-90

application record 27

back and forth 88-89

racetrack 88, 89

Flight S tandards D istrict O ffice 28, 101

flow meters, valves, and pressure gauges 48-49

flow volume 66-67

flow volume controllers 49, 53, 54

F SDO 28, 101

fuel and oil check, preflight 22



# G

gallons per minute, determining 67-70

general standards for certified commercial

applicators 11

general types of pesticides 11

general-use pesticide 11, 13

generator, smoke 40

global positioning system 52, 53, 54, 108

differential 52, 53, 54, 108

G PS 52, 53, 54, 108

antenna 53

light bar 53

systems 53

granule 57-60

applying 57-60

calibrating applicators for 69, 75-78

spreader 57-60

ground crew

checklist 86

emergencies 28-29 member 18, 19, 21, 22, 23, 24, 25, 27, 28, 29, 30,

43, 56, 60, 82, 84-86

onsite, importance of during an application 84-86

ground equipment 17, 22, 23



# H

habits, employee 19, 21-22

handler, pesticide 19, 20-22, 26, 29, 65

harvested crops, residues on 64

hazards, flight 25, 28, 29, 54, 81, 83, 87-88

hazards, health 11, 12, 17, 19, 20, 26, 27, 30, 84

health, human 20, 64

heat and heat stress 20, 21, 22, 113

height, application 22, 24, 28, 38, 40, 65, 68, 75,

87, 90

hollow-cone pattern nozzles 49, 50, 51-52

hopper, pesticide 43, 45-46, 58-60, 64, 75

human exposure, preventing 29

human flagger 29, 40, 53, 85

human health concerns 20, 64

humidity 28, 37-38, 54, 68, 92

effect on granule flow 75

pesticide label restrictions 84

hydraulic agitation 46, 52



# I

illness, heat-related 20, 21, 22, 113

importance of onsite ground crew during an

application 84-86

interior baffles 45

inversion, temperature 34, 37, 38-39, 40, 84, 92



# L

label and labeling

comprehension 11

conflict with 27

instructions 10, 11, 12, 13, 24, 25-26, 29, 30, 36,

43, 63, 64, 65, 68, 69, 75, 83, 84, 86

pesticide 12-13, 20, 22, 23, 24, 25-26, 29, 36, 63,

64, 65, 68, 69, 75, 83, 84, 86

precautionary statement 13, 29

laws and regulations 9-12

local 10

leaching 33

length, spray boom 24-25, 39, 49, 55121 INDEX light bar, G PS 53

limitations, personal, pilot 24-25

line screens 46, 49, 56

liquid dispersal system components 43-54

liquid spraying equipment, calibrating 65-75

local laws and regulations 10

local weather conditions 25, 82, 90

low volume 45, 47, 49

L V 49, 50



# M

making an aerial pesticide application 81-94

malfunction, application equipment 23, 29, 48, 49

maneuvers, emergency 23, 24

map as-applied 28, 54

endangered species area protection 12

mapping systems 52, 53, 54

mechanical agitation 46

Medical Certificate, Class II 10

medications, over-the-counter and prescription 21

mesh 46, 51

micron 34, 35, 36

minimizing off-target drift 39-40

mixing equipment, types of 12



# N

NAAA 13, 93-94

N ational A erial P esticide A pplicator P ilot

Certification E xamination 1

N ational A gricultural A viation A ssociation 13,

93-94

N ational Coalition on D rift Minimization 34

N ational W eather S ervice 38

N C OD M 34

negative pressure, system 46, 47

non-target organism 10, 11, 19, 21, 22, 24

notification and posting requirements 26

notification requirements 26

nozzle

anti-drip device 45, 52

classification by droplet spectra 35-37

orientation 24, 28, 35, 39-40

hollow-cone pattern 49, 50, 51-52

orifice size, changing 46, 57, 75

positioning 48, 54-60 rotary atomizer 50, 51

screen 46

straight stream 49, 50

variable flow rate 49, 50

variable orifice flood 49, 50, 51

wind shear 39, 51, 57, 75



# O

obstructions, avoiding during application 83,

87–88, 89

off-target

drift, minimizing 33-40, 75, 81, 86, 87

pesticide drift, preventing 13, 24, 33-40, 75,

81-86, 87

pesticide movement 27, 29, 34, 40, 68, 87, 90

onsite ground crew, importance of during an

application 84-86

operating pressure, spraying system 24, 28, 36, 39,

40, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 57

O peration S

. A .F. E

. 93-94

operation, agricultural aircraft 101-104

operator, aerial pest control 1, 9-13, 25

laws and regulations for 9-13

output
changing 75

rate, spray 76

sprayer, changing 71

volume, spray 115

overcompensation, prop wash 55

overspray, drift, and other misapplication 29-30

over-the-counter and prescription medications 21



# P

PAASS 13

pattern testing a spray boom 54, 55-57, 68

pattern, application

back and forth 88-89

racetrack 88-89

per acre application volume, determining 69-70

personal limitations, pilot 24-25

personal protective equipment 20, 21, 22, 26, 30

pest control operator, aerial 1, 9-13, 25

laws and regulations for 9-13

pesticide

amount to put into the tank, determining 64, 69-71

applicator certification 1, 2, 10-12, 27122 INDEX applicator pilot, aerial 1, 9

drift 12, 13, 20, 23, 24, 25, 29, 33-40

environmental fate 11

exposure routes 11, 20

general types of 11

handler 19, 20-22, 26, 29, 65

label 12-13, 20, 22, 23, 24, 25-26, 29, 36, 63, 64,

65, 68, 69, 75, 83, 84, 86

label directions 24

label restrictions, understanding 25-27

laws and regulations 9-13

poisoning symptoms 11

regulatory agency 1, 10, 11, 13, 21, 22, 39, 63

regulatory agency contact information 98

restricted-use 1, 11, 13, 27

spill, steps to follow when cleaning up 20, 107

tanks and hoppers 45

toxicity 11

uses, selective 10

pilot

aerial pesticide applicator 1, 9

checklist 85

in command 10, 101

qualifications and limitations 24-25

pipes, hoses, and fittings 46-47

piping 46, 47

planning for emergencies 28-30

plans in case of aircraft crash 29

poison, economic 10

positioning booms and nozzles 48, 54-57

positive shut-off valve 24, 47, 52

post-application volatilization 33, 34

posting requirements 26

PPE 20, 21, 22, 26, 30

preflight fuel and oil check 22

pressure gauge 48, 49

pressure
system operating 24, 28, 36, 39, 40, 44, 45, 46,

47, 48, 49, 50, 51, 52, 53, 54, 55, 57

system, negative 46, 47

preventing

dehydration and heat related illness 22

human exposure 29

off-target pesticide drift 13, 24, 33-40, 75, 81, 86, 87

procedures

for diluting pesticide concentrates 12

P rofessional A erial A pplicator’s S upport S ystem 13 prop wash 54, 55

displacement 54

overcompensation 55

protective clothing and equipment 20, 21, 22, 26, 30

pump centrifugal 45, 46

fan-driven 44, 45, 51, 66



# Q

qualifications and limitations, pilot 24-25



# R

racetrack application pattern 88-89

rainfall or irrigation water 34

ram-air spreader 58-60

reasons for calibration 64, 65

record keeping 27-28

registration number, EPA 27

regulations, federal aviation 10

regulatory requirements 9-11

requirements

for certification, EPA 10-12

personal protective equipment 26

regulatory 9

residues on harvested crops 64

resolving conflicts 27

response plan, emergency 28-30

rest break 23

restricted-use pesticide 1, 11, 13, 27

review question answers 97

rotary atomizer 50, 51

rotor

distortion 55

vortex 25, 39, 55

routes of exposure, pesticide 11, 20

R UP 1, 11, 13, 27



# S

S

. A .F. E

. 93-94

safety hazards 11, 12, 17, 19, 20, 26, 27, 30, 84

safety program, well-developed 19

scouting the target site 22, 25, 30

screen, nozzle 46123 INDEX securing

facilities, storage areas, and surrounding

property 17-19

pesticide application aircraft, vehicles,

and equipment 17-19

security, aerial application operation 17-19

selective pesticide uses 10

S elf Regulating A pplication and Flight E fficiency 93

sensitive area, environmental 25, 26

service container 10

shear

viscosity 36, 37

air 39, 40, 51, 57, 75

shut-off valve, positive 24, 47, 52

smoke generator 40

soil contamination, reason for calibration 65

SOP 30

spectra, droplet, nozzle classification by 35-37

speed

application 24, 27, 28, 39-40, 43, 44, 47-51, 54,

57, 64, 65-69, 71, 75, 87, 88, 89, 90, 92

application, changing 71, 75

spill

cleaning up 107

cleanup kit 28, 29, 107

spray

boom 47-48, 49, 51, 52, 53, 54-56

boom length 24-25, 39, 49, 55

boom pattern testing 54, 55-57, 68

nozzle classification by droplet spectra 13, 35,

36, 37, 38, 39

output volume 53, 54, 57, 65, 66, 67-71, 75

pump, centrifugal 45, 46

pump, fan-driven 44, 45, 51, 66

tank vent 45

tank volume 69

volume and dilution restrictions 13

sprayer output, changing 71

spraying system operating pressure 7, 36, 57

spreader

mounting 59-60

dry material 57-60

granule 58-60

ram-air 58-60

vanes 58-59

standard droplet size categories 24, 28, 36, 39, 40,

44, 45, 46, 47, 48, 49 50, 51, 52, 53, 54, 55, 57

standard operating procedures 30 standard S -572.1, ASABE 36-37

staying alert 22

steps to follow in cleaning up a pesticide spill 107

storage areas, securing 18

straight stream nozzle 50

suck-back 40, 43, 46, 47, 52

surface tension, dynamic 36, 37

swath

application 28, 40, 45, 51, 53, 55, 56, 57, 58, 59, 60,

65, 66, 67-68, 70, 75, 76-77

width, effective 55, 56, 57, 60, 66, 67-68, 69, 76, 87

symptoms of pesticide poisoning 11

synergism 11



# T

tank

agitation 46

capacity 65-66, 70

pesticide 45-46

vent 45

volume 69

target site, scouting 22, 25, 30

technique, application 12, 40

temperature inversion 34, 37, 38-39, 40, 84, 92

toxicity, pesticide 11

training

handler 20-21

turnaround, application pattern 89-90

types of application and mixing equipment 12, 44-60



# U

U

. S

. D epartment of H omeland S ecurity 19

U

. S

. E nvironmental P rotection A gency 10-13, 19

U

. S . Federal A viation A dministration 10

ultra low volume 45, 49, 50

U L V 45, 49, 50

unauthorized access 11, 17, 18, 19, 21, 31, 84

understanding

pesticide label restrictions 25-26

the work order 23-25

using the G PS light bar 53



# V

valve, positive shut-off 24, 47, 52

vanes, spreader 58-59

variable flow rate flat fan nozzle 50-51124 INDEX variable orifice flood nozzle 51

vent, spray tank 45

viscosity, extensional 36

viscosity, shear 37

V M D 35, 36

volatilization, post-application 33, 34

volume

application 45, 49, 50, 51, 54, 55, 63, 64, 65, 66,

69, 71, 75, 87

spray tank 69

volume median diameter 35, 36

vortex

rotor 25, 39, 55

wing tip 25, 39, 48, 54, 55 

# W

weather

conditions, local 25, 82, 90

factors 24

well-developed safety program 19

what to watch for during an application 83-86

why you need to calibrate equipmen t 64-65

wind shear on nozzles 39, 40, 51, 57, 75

wingtip and rotor vortex 54, 55

work crews 25

work order, understanding 23

W orker P rotection S tandard ( WPS ) 12, 20, 26