In the acronym "GUMP" for pre-landing checks, what does the "A" stand for?

In the pre-landing checklist represented by the acronym "GUMP," the "A" stands for Mixture. This step is essential as adjusting the mixture setting optimizes engine performance and fuel efficiency. As the aircraft descends for landing, a proper mixture setting ensures that the engine receives the correct fuel-to-air ratio, preventing engine roughness or potential power loss.

This emphasis on mixture is particularly critical in conditions where altitude changes can affect engine performance, such as when approaching a landing at different elevations or in varied atmospheric conditions. While factors like airspeed and altitude are also crucial for landing, they are represented by different components of the acronym—making Mixture the correct interpretation of the "A" in GUMP.