Originally Posted by
Check Airman
It would be rather u usual to enter the traffic pattern as you've described in the first scenario. The last is way more likely- you'd be doing some sort of approach, in which case you'd land straight in.
In the rare event that you'd have to circle, the terrain would play a more important role in deciding left or right traffic.
His point is well taken. Perhaps the airport only has one ILS and wind dictates landing on the opposite end of the runway. FAR 91.126 (b) (1) comes into play.