If one or more pressure relief valves are open and the differential pressure is below 7.8 psid or decreasing, what should you do?

The best course of action when one or more pressure relief valves are open and the differential pressure is below 7.8 psid or decreasing is to descend to 25,000 feet or less. This reduces the cabin altitude and helps maintain an adequate differential pressure across the aircraft's structure, which is critical for maintaining cabin integrity and passenger safety.

At higher altitudes, the risk of reduced cabin pressure becomes significant, especially if the pressure relief valves are actuating to relieve pressure. Descending to a lower altitude allows the aircraft to operate within safer parameters while the issue is addressed, and 25,000 feet is generally considered a safe altitude where the effects of hypoxia are less pronounced for most individuals.

While other altitude options may be relevant, descending to 25,000 feet ensures that the aircraft and its occupants are in a safer environment, reducing the potential for hypoxia and associated risks.