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United States Department of Agriculture

Agricultural Research Service

Title: Effects of Lowering Spray Boom in Flight on Swath Width and Drift

Authors
item Hoffmann, Wesley
item Tom, Hal

Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 1, 2000
Publication Date: N/A

Interpretive Summary: Drift is one of the leading concerns facing aerial applicators. With increasing pressure from regulatory agencies and environmental groups, applicators must take advantage of technologies that can reduce the risk of agricultural protection materials moving beyond their intended target areas. A potential new technology is the use of drop or lowered spray booms to increase the distance between the spray release point and the turbulence generated by the trailing edge of the wing. This increased distance increases the time that droplets have to reach their target before they are subjected to turbulent forces, which may influence where the droplets are deposited. A new spray boom system was designed and constructed for use on an agricultural aircraft. The boom system lowers and brings forward the spray boom once the aircraft is in the air. This greatly increases the distance between the spray release point and the trailing edge of the wing. This new system was found to increase the swath width or effective area of coverage by 10 percent. This will make the aircraft more productive. Lowering the spray boom also significantly decreased the amount of material that deposited outside of the intended area.

Technical Abstract: Drift is one of the major concerns of aerial applicators. With increasing encroachment of urban areas into agricultural lands and more stringent regulatory conditions, aerial applicators must use new technologies to make applications more efficient. A spray boom system for aircraft was designed, constructed and tested. The spray boom is lowered by 0.45 m (1.5 ft) and moved forward 0.37 m (1.2 ft) once the aircraft is in the air. The purpose of constructing the system was to increase the distance between the spray release point and the turbulence generated by the trailing edge of the wing. The system components created an additional drag force on the aircraft of 580 N (130 lb); however, no performance effects were noticed. During in-wind swath analysis tests, the swath width was increased by 1.9 m (10.3 percent). A drift test was conducted to compare the drift from the spray system with the boom in the raised (original) versus lowered positions. There was 25.9 and 55.9 percent less deposition at 10 and 310 m from the flightline, respectively, with the boom lowered.

Last Modified: 7/22/2014