When the aircraft is on a 90-degree approach to the landing runway, the term used to describe this approach is?

When an aircraft is on a 90-degree approach to the landing runway, this is known as the base leg of the approach. During the base leg, the airplane is positioned perpendicular to the final approach path, allowing pilots to align themselves with the runway for the final landing maneuver. Typically, pilots will make this turn from the downwind leg, which follows the runway parallel and then transitions onto the base leg to prepare for landing.

The base leg provides an opportunity for the pilot to configure the aircraft for landing, check all necessary systems, and ensure the final approach is clear and safe before turning onto the final approach path. Understanding this sequence of legs in the traffic pattern is crucial for safe aircraft operation and efficient runway use at airports.