what does "downwind leg" mean

Question

in January 1970 I was on the downwind leg of my senior year in high school, and the Chicago Public Schools had installed a computer somewhere. A truck full of these fancy IBM typewriter gadgets was delivered to Lane Tech, and a bewildered math teacher was drafted into teaching computer science (as they had the nerve to call it) to a high school full of rowdy males.

Answer 1

مطمئن نیستم اما بعید نیست می‌خواد بگه اواخر یا توی نیمه‌ی دوم سال ارشد دبیرستان.