What happens if the GPS database is expired when attempting an instrument approach?

When the GPS database is expired, the approach cannot be flown because the aircraft's navigation system relies on current and accurate data to execute instrument approaches safely. An expired database means that the information pertaining to waypoints, procedures, and altitudes may be outdated or incorrect, leading to potential navigation errors. Therefore, for safety and regulatory compliance, it is required to have an up-to-date navigation database to ensure all instrument procedures reflected in the GPS are valid and safe to use. Conducting an approach with an expired database poses significant risks, which is why the correct course of action is to refrain from flying the approach until the database is updated.