What is a sign that the emergency hydraulic accumulator is fully charged?

A fully charged emergency hydraulic accumulator is indicated by a pressure gauge reading above 2400 psi. The accumulator, designed to store hydraulic fluid under high pressure, operates effectively when its internal pressure meets or exceeds this specified range.

In context, the pressure gauge serves as a direct measurement of the accumulator's current state. A reading above 2400 psi demonstrates that the system has sufficient hydraulic pressure available to function correctly in emergencies, ensuring that critical systems can operate if the primary hydraulic system fails.

Other indicators, such as green lights or unlit annunciators, can suggest either normal operation or readiness of various systems but don’t specifically confirm the accumulator's charge state. Similarly, an illuminated warning signal like EHYD PX LO would indicate low hydraulic pressure, which is the opposite of what indicates a fully charged accumulator. Therefore, the pressure gauge is the most reliable and direct method of gauging the accumulator's readiness.