If there is a fault in the Master Controller handle, what is the first step a driver should take?

In the event of a fault in the Master Controller handle, the appropriate initial action is to place the handle into emergency. This action is crucial because it establishes a state that can help prevent further issues, such as unintended acceleration or loss of control of the train. By switching to emergency mode, the driver effectively engages the emergency braking system, which is designed to halt the train safely and immediately in case of malfunction.

Taking this step ensures safety for both the crew and passengers by prioritizing immediate risk management. While notifying the conductor and pressing the emergency stop button are important actions, they may follow after securing the situation by initially placing the handle into emergency mode. Transitioning to coast mode is least suitable as it does not actively address the fault and could lead to loss of control.