Aviation Speak

The way traffic patterns at airports work is one of the first things that you learn as a student pilot, and it is information that you will use every time you fly, whether you are in a Boeing 777 or a Cessna 150. Because traffic patterns are an integral part of flying, the Aeronautical Information Manual includes a detailed definition of the term and its component parts to ensure that pilots and controllers understand one another. While it's always important for pilots and air traffic controllers to speak the same language, it is especially critical near airports where traffic density increases.

The typical components of a traffic pattern are the upwind leg, crosswind leg, downwind leg, base leg, and final approach. While all of these elements are considered part of the traffic pattern, the segments you actually use will depend on the circumstances, and you may find yourself flying a complete circuit or, at the request of the tower, making a straight-in approach to landing that eliminates all but the final approach leg of the pattern. Many pilots and instructors take a dim view of straight-in approaches at nontowered airports because you may barge into an already-established flow of traffic following the traditional pattern and because you may inadvertently cut off - or collide with - someone trying to make the turn from base to final.

The upwind leg is defined as a flight path parallel to the landing runway in the direction of landing - in other words flying into the wind, the same way that you would be landing. This is probably the least-used segment of the pattern.

The crosswind leg is a flight path at right angles to the landing runway off its upwind leg. You will most often fly this leg if you are practicing touch and goes or other maneuvers that keep you in the traffic pattern.

The downwind leg is a flight path parallel to the landing runway opposite the direction that you will be landing; in other words, you are flying with the wind or down wind. This leg typically begins after turning from the crosswind leg and extends until the turn onto the base leg.

The base leg, like the crosswind leg, is at right angles to the landing runway, but the base leg is flown at an appropriate distance from the approach end of the runway. It typically reaches only as far as the extended runway centerline.

The final approach leg is a flight path along the extended runway centerline in the direction of landing. This leg extends from the base leg's intersection with the runway to the runway itself. An aircraft making a straight-in approach under visual flight rules is also considered to be on the final approach leg of the pattern even though the leg may extend well beyond the base leg of a standard traffic pattern.