How long does "WAIT" display on the PBIT after powering up the ELES before the CDP displays the ELES status menu?

The "WAIT" display on the Power-On Built-In Test (PBIT) of the Enhanced Launcher Electronic System (ELES) serves as an important indication of the system's initialization process. During this initial period, the system performs various self-checks and diagnostics to ensure that all components are functioning correctly before presenting the status menu to the user.

In this case, the length of time that "WAIT" is displayed is critical for ensuring that the system is fully operational and ready for subsequent commands. The correct duration, identified in the question, is 40 seconds before the Crew Display Panel (CDP) transitions to showing the ELES status menu. This duration allows for thorough verification of system integrity and operational capability, thus preventing premature usage before the system is completely ready.

Other durations, such as 20, 30, or 60 seconds, either do not provide sufficient time for comprehensive testing or exceed the required time frame, potentially leading to unnecessary delays in system readiness or misinterpretation of the system's operational state. Thus, recognizing the correct 40 seconds ensures that the operator is informed of the appropriate time for effective system startup sequences.