Five agricultural aviation companies that
serve the agricultural industry in Louisiana
got their equipment tested Oct. 4 at the Jennings
airport with the help of the LSU
AgCenter and the Louisiana Department of Agriculture
and Forestry (LDAF).
Liquid testing was conducted to determine if the
airplanes’ spray systems have an even distribution.
Pattern testing is important to reduce chances of
crop injury when applying herbicides, as well as
chemical drift. Pilots sprayed a mixture of tap water
and a red dye over a 1-mm cotton string. Watersensitive
papers are used to detect spray patterns,
and a computerized system analyzes the string and
compares the distributions.
Personnel from the LDAF and LSU AgCenter
worked to set up the testing.
“We’re trying to do this throughout the state,”
says Billy Precht, president of the Louisiana Aerial
Applicators Association (LAAA) and owner of Riceland
Aviation of Jennings. “In the spring, we hope to
do this in north Louisiana.”
Aircraft Are Tested To Industry Standards
The effort is based on a national program as complaints about
pesticide and herbicide drift have become more of an issue in recent
years, Precht says. “This is something we’ve needed, and we’re just
getting in on the ground level. It’s all part of self-regulation.”
The fly-in provides the chance for older pilots to pass down their
knowledge to younger ones, he said.
LSU AgCenter agricultural engineer, Roberto Barbosa, analyzed
the test data to determine how well an airplane’s spraying mechanism
“We’re making sure our equipment is up-to-date and working
properly, and we have proof of it,” says Robert LeJeune of LeJeune
Aerial Applicators, based in Basile. “This is how we show our aircraft
has been tested to industry standards.”
“It’s more or less making sure our equipment is doing the job,”
The testing saves hundreds of dollars in fuel that would be required
to troubleshoot a problem, and the testing does not require spraying
any expensive chemicals, he says.
LDAF officials encouraged the testing, says Bradley Reed, vice
president of LAAA and owner of Reed Aviation based in Iota. “They
came to us and said we’d like to see it, and, fortunately, we have the
LSU AgCenter Extension Service to help us.”
Cooperation between the state agencies made the program work,
LeJeune says. “We really have some people with a lot of energy and
good ideas in LDAF and the Extension service.”
Engineer Strives To Modernize Testing Equipment
Pilots usually make three passes over the 150-foot cotton-string system.
In the first two passes, only the string is used to record spray pattern.
In the third pass, water-sensitive papers are used to document
On this day, no problems were found in airplanes from all five
LSU AgCenter agriculture engineering research associate, Yin-Lin
“Jack” Chiu, is working to modernize the testing equipment, including
a fluorometer that reads the spray distribution on the string. Other
instruments automatically gauge an airplane’s speed and height,
wind speed and direction and several other variables.
Barbosa has conducted the testing for several years, but he said the
LDAF asked the LAAA to assume a leadership role to get a voluntary
program throughout the state.
Arkansas requires regular testing, Barbosa says. “We’re trying
to keep the program voluntary, but we do want to see every pilot at
least every three years.”
LSU AgCenter contributed information for this article.