What is the base leg in a traffic pattern?

The base leg in a traffic pattern is defined as the course between the downwind leg and the final approach leg. This phase of flight occurs after the aircraft has made a turn from the downwind leg and is preparing to line up with the runway for landing. During the base leg, the pilot reduces airspeed and descends to align with the runway's approach path.

This part of the traffic pattern is crucial for several reasons. First, it allows the pilot to establish a proper spacing from the runway and other aircraft in the pattern, as well as verify that the aircraft is ready for landing configuration. It also provides an essential reference point for the visual flow of traffic around the airport, ensuring that pilots can consistently and safely transition from the downwind phase to final approach.

The other choices describe different aspects of a traffic pattern: the section leading to the landing runway is the final approach; the final approach itself is where the aircraft aligns directly with the runway for landing; and the initial departure leg from the runway refers to the phase when the aircraft first takes off and begins to climb. Each of these elements is essential in the overall structure of the traffic pattern but does not define the base leg specifically.