UNITED STATES
IN MY OPINION
Robert McCurdy bluemaxs2rt@gmail.com “Ag-Pilot Instructor — Retired”
Drifting Into Trouble
Moral of the story, and I emphasized this to my ag aviation students, a nowind condition is a very insidious danger.
B 32 | agairupdate.com
During the early ‘90s, I was flying an AT-401 out of Swan Lake, Mississippi. We got a call one morning from one of our rice farmers to Stam a 90-acre rice field. I checked the maps and identified the field to be sprayed. The field was bordered on the west and east by other rice fields belonging to this same farmer and to the south by a “lay-out” field which really was only used for duck hunting when it would be flooded later in the year. To the north was a small scope of woods, maybe 25 yards deep. Lengthwise, it extended beyond both boundaries of the rice field to be treated with Stam, but immediately on the other side of the woods was a large field with a cotton stand of about three inches in height. Naturally, the cotton belonged to another farmer and was not one of our regular customers. The DTN indicated the wind to be light and variable and our windsock was hanging like a wet dish rag. Calm winds have always made me a little nervous when doing herbicide work. After ordering the material, figuring the loads and working up the strategy for the job, we determined it would be better to do the fly from our base, approximately ten miles from the job site. I called the farmer and told him I was a little concerned about the wind, or lack thereof. I would have liked to have had a gentle breeze out of anywhere, as long as it had some northerly component. The farmer expressed that it was near critical that the job be done asap. I needed the farmer’s assistance and we discussed the coordination strategy. I would lay a line of smoke from east to west along the north edge of the rice to be sprayed. The farmer assured me he would be at the north end of the rice field watching the wind and if it appeared that the smoke was moving towards the woods, he would wave me off and the application would be
terminated. I told him I intended to leave a 100foot buffer between my cut off point and the tree line and that I would be back to spray the buffer as soon as we had a northernly wind. I took all the standard precautions, using only about 22 psi boom pressure and adding a drift control agent to the mixture. Everything went, “According to Hoyle.”
FAR 91.3(a) and 137.39(2) clearly state, “the pilot in command is directly responsible for and is the final authority” After mixing the first load and flying north to the destination rice field, I observed the farmer in position. I laid a line of smoke across the north border of the rice field, pulled up and saw that it was not moving. The farmer gave me the OK signal and I laid down the first pass of the east perimeter, flying north and cutting the spray off before beginning the pull-up with at least a 100foot buffer. The farmer observed the pass and signaled again that everything was a “go.” I made several more passes, releasing a puff of smoke on each pull up and watching the farmer for any signals. After about five or six passes, for some reason I decided to make another east-west run along the north boundary with a line of smoke and sure enough it was slowly moving into the trees. I quit spraying, but it was too late now. I damaged about 28 acres of cotton, as I remember. The farmer told me later that it had looked like all the material was settling before it got to the trees and
