Description
Helicopters with boom sprayers are well suited for use in mountainous areas, steep terrain, sites with highly irregular shapes and remote areas. They are highly maneuverable and apply sprays at much slower speeds than fixed-wing aircraft. Airspeed can vary from 30 to 80 mph but is about 45 mph for brush and weed spraying. To maintain precision application rates, aircraft should be equipped with variable-rate, flow-control units to compensate for changes in airspeed. GPS/GIS systems are helpful for precision applications. Spray tanks vary in size from 90 to 230 gallons, and the spray boom should not exceed 90% of the rotor diameter. Many types and sizes of nozzles are available.
Application
The conditions and regulations outlined in the fixed-wing aircraft section also apply to helicopters. Applications must follow the chemical’s Product Label, and the applicator must be certified by the state. Batch trucks that carry clean water and chemical mixing tanks for helicopters usually have landing pads atop the truck for convenience and safety in servicing. Ground personnel must always be alert to the helicopter’s moving rotors during servicing. Helicopters are more expensive to operate than fixed-wing aircraft, but they have the advantage of operating where fixed-wing aircraft cannot. Helicopters do not need landing strips and are adapted to remote rugged terrain and irregularly shaped sites. GPS/GIS units negate the need for flagmen in these remote sites and can record flight patterns.
Images
References / Additional Information
Fitch, K. 2025. Shrub-steppe and grassland restoration 6 common mistakes. In: 2025 Society for Range Management Annual Meeting, 2025 February 9-13; Spokane, Washington.
Gebhardt, M.R. 1984. Foam marking systems for rangeland sprayers. In: 38th Annual Report of the Vegetative Rehabilitation and Equipment Workshop (VREW); 1984 February 14-15; Rapid City, SD. Missoula, MT: USDA Forest Service Equipment Development Center: 33-35.
Jacoby, P.W. 1987. Chemical control. In: 41st Annual Report of the Vegetative Rehabilitation and Equipment Workshop (VREW); 1987 February 8-9; Boise, ID: USDA Forest Service Equipment Development Center: 10.
Stevens, R.; Monsen, S.B. 2004. Chapter 9. Mechanical plant control. In: Monsen, S.B.; Stevens, R.; Shaw, N.L., comps. Restoring western ranges and wildlands, vol. 1. Gen. Tech. Rep. RMRS-GTR-136-vol-1. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 65-88.
Young, J.A. 1983. Ground sprayers for sagebrush rangelands. In: 37th Annual Report of the Vegetative Rehabilitation and Equipment Workshop (VREW); 1983 February 13-14; Albuquerque, NM. Missoula, MT: USDA Forest Service Equipment Development Center: 29-33.