I let every student know up front that I cant save it every time. The lower the altitude the less time I have. I dont let them get too far away. They know that landing and takeoffs is where there will be the most damage done. We've had a few students finally quit. But it was because we had been training them for about a year. Both older guys that just didnt have the eye hand coordination. I told them I'd stay with them as long as they wanted. We had a wise crack by one of the young pilots and I imediately told him, "Watch it, I garuntee you'll be there someday'.
Edwin