What is the first step to perform a train check once the train is "Standing"?

Applying the train air brakes with at least a 10 psi brake pipe reduction is indeed the first step to perform a train check once the train is "Standing." This action serves to ensure that the brakes are fully engaged, allowing for a proper evaluation of their effectiveness and guaranteeing that the train is secure before any further checks are conducted.

The 10 psi reduction is significant as it allows the conductor or crew members to assess the air brake system's responsiveness and verify if there are any leaks or issues within the system. By confirming that the brakes are functioning properly before proceeding with additional checks, safety is prioritized, as the train remains in a secure state.

Following the application of the brakes, other tasks such as verifying the status of remote consists, initiating the TRAIN CHECK process, and checking for leaks can be performed confidently because the brakes ensure the train remains stationary. Therefore, starting with the brake application is foundational to conducting a complete and effective train check.