What is the first step in executing a Class I Brake Test?

The first step in executing a Class I Brake Test involves coupling the engine to the cars and requesting 3-step protection. This is crucial because it establishes the necessary safety protocols before conducting further tests. The 3-step protection ensures that other crew members are aware of the test being conducted and can respond accordingly to ensure safety throughout the procedure.

By coupling the engine to the cars first, the crew can ensure that all components are in place and ready for testing. Establishing communication and safety protocols is a critical aspect of railroad operations, especially when dealing with brake systems that can significantly affect the safe movement of trains.

This first step sets the foundation for the subsequent steps in the testing process, which cannot be effectively conducted without first ensuring proper coupling and communication.