ON THE FARM...Crop Dusters Improve Their Aim

Worn or improperly aligned spray nozzles, or spray system leaks, can cause crop dusters to spray unevenly. This means that the pesticide (bug killer), herbicide (weed killer) or fertilizer may have to be sprayed over again. That costs farmers and crop dusters extra money.

NASA worked with Oklahoma State University (OSU) to develop a system for telling crop duster operators if their spray pattern is in good shape. NASA provided a funding grant, along with wind tunnel tests and computer models done at Langley Research Center and Wallops Flight Center.

Old methods for testing crop duster spraying patterns used to take days or weeks. The OSU system takes only a few hours. The mobile system consists of a 100-foot frame connected to a computer. OSU hosts “fly-ins” all over the state. A fly-in typically draws 50 to 100 crop dusters and suppliers.

A plane’s tanks are filled with a dyed liquid. The pilot flies the plane over the measurement frame, spraying away. As the plane flies over the frame, droplets of the dye fall onto a paper tape running the 100-foot length of the frame. The tape then feeds into a scanner that analyzes the amount of droplets that fell on the tape. The computer provides a printout that shows the "peaks and valleys” of the spray pattern.

The crop duster pilot can adjust the plane’s spray nozzles on the spot, and fly over the frame again for another printout.

The OSU system was adopted by the National Agricultural Aviation Association, as the backbone of a program to improve the safety and efficiency of crop dusting.