Under what circumstances would a "holding pattern" be used?

A holding pattern is specifically utilized in aviation to allow an aircraft to maintain its position while waiting for clearance to land or to enter an approach. When an aircraft reaches the clearance limit but is not yet authorized to descend or land, the pilot enters the holding pattern. This is a pre-defined flight path, typically a racetrack shape, that keeps the aircraft within a specified area while waiting for the air traffic control approval to proceed.

This procedure is especially important for managing air traffic and ensuring safe spacing between aircraft, particularly when there is congestion at an airport or issues affecting the immediate landing area. It allows flights to remain organized and ensures that operations at the airport can continue smoothly.

Other scenarios provided, such as fuel calculations, takeoff procedures, and altitude adjustments, do not involve holding patterns. While they are essential parts of flight planning and execution, they are not related to the specific function of maintaining an aircraft's position while awaiting landing instructions, which is the primary purpose of a holding pattern.