What is used to check the status of a PA5 car when operating?

The MC handle is critical for checking the status of a PA5 car when it is operating because it serves multiple functions related to the control of the train's movement and condition. When the train engineer utilizes the MC handle, they are able to engage or disengage the train's power supply, monitor brake systems, and assess key operational indicators, which all contribute to ensuring the car is functioning correctly.

In contrast, while the control box may contain various operational controls for the train, it does not directly interact with the current operational state in the same hands-on manner as the MC handle. The overhead trolley is not involved in monitoring the state of the PA5 car; rather, it's part of the physical infrastructure that supplies power to the train. Similarly, the door interlock system is a crucial safety feature that ensures doors are secure before the train can move but does not provide a comprehensive status check of the vehicle's overall operational readiness.