We had a crop duster flying a field next to our house the other day so I thought I would see how close I could get, without getting sprayed of course.
I was able to get in a spot where he was making his turn and coming back around to the field. This was taken just before he got to the field and is not cropped at all. The plane was only about 50 feet above my head we I took this.
This looks like it would be a lot of fun but the only thing I can think of is a scene from the movie Space Cowboys where Tommy Lee Jones took up a kid on a birthday flight and it didn't end well for the kid.