[ursus]

Your mention of markers setting the line for the next pass from a cropduster reminds me of my wife's chagrin at always being passed over for what was then a relatively easy and well paid job back then. Two of her erstwhile friends were able secure such desired employment, both having died of cancer in their thirties. The wife still cannot reconcile the irony.

I recall growing up in a house that bordered a large barley field. The wood shingled roof needed replacement and when the crew arrived for work they seemed to hold off after noting an old Stearman biplane working over the adjacent field. They signaled to the pilot and it soon became apparent that it was for him to just barely clear the roof at the end of each pass. The impact of propwash from that low pitch propeller made their job easier as it lifted off and launched a good portion of the shingles into the next field. I still recall the grin of the pilot as he bombed our house.