I know this is only my second post but i hope the pictures below work.
I have been fortunate enough to know Mike Horrell for the past seven years, and he took me through my PPL, CPL and FI ratings.
I have been lucky enough to work along side Mike while crop spraying, I started off learning about the ground equipment and ground crewed for three years prior to spraying myself.
During the months of July and August each year we go off around the UK spraying bracken. We usually use three R22's, one is based in the Highlands and Islands, one in the Borders and the third in Engalnd and Wales. Along the way I have been lucky enough to fly with some really experienced pilots, just to name a few: Noel Boyd (featured in The Last Great Adventure), Colin Bint (RIP) a true gent and Andy Brown from around Nelson.
The spraying aspect of the job is really quite tricky, very few of the areas that we spray are marked out using flags, therefore we use line features on the ground. Each job is different and I constantly learn each time I go out.
In N.Z. Dynamic GPS is used to plot out the spraying area and you can add in your swath width. This then produces a grid which you can follow on the screen (correct me if this is wrong as I have not seen this system before). When the job is finished you can get a print out of the area which has been sprayed and you can hand this to the client.
The draw back to this type of spraying is that you can not see where you have or have not been. The chemical which we use kills the bracken the following year and if you accidently miss an area you can end up with stripes - not good!! Bracken is really the only crop which we are allowed to spray in the UK however we have been out in Oman spraying date palms using insecticide.
Hope this gives a small insight into spraying - here are some pics
Me taking off
Me landing
And the equipment (notice the spray booms are just inside the disc area to reduce vortices)
Links fixed.
Heliport