Traffic pattern

In aviation, a traffic pattern is a standard path followed by aircraft when departing, landing or practicing landings and take-offs (touch-and-go landings). The traffic pattern has five parts or legs. After takeoff, still on the runway heading, the aircraft is on the upwind leg (regardless of the actual wind direction). If the aircraft does not depart the pattern without turning (an upwind departure) it will make a 90 degree turn to the right or left following the crosswind leg of the pattern. The next leg follows another 90 degree turn to fly parallel to the runway in the opposite direction from take-off. This is the downwind leg. The next leg is 90 degrees to the runway where the aircraft has started its decent in preparation to land. This leg is called the base-leg. When the aircraft lines up with the runway to land it is on the final approach leg of the pattern.