To qualify a train air brake system using the Air Flow Method (AFM), which of the following is required?

The correct response focuses on the requirement for the locomotive to have an air flow indicator when qualifying a train air brake system using the Air Flow Method (AFM). The air flow indicator is crucial as it measures the airflow from the locomotive through the brake system, allowing for verification of the system's functionality. This measurement is essential to ensure that the brakes are responsive and operating correctly, which directly impacts the safety and efficiency of train operations.

Having an air flow indicator enables the crew to monitor the air brake system during the test process. As air flows through the system, it provides a clear visual representation of the air pressure and flow rate, which are critical parameters in assessing the system’s performance and troubleshooting any potential issues. This functionality is specific to the AFM qualification process, distinguishing it from other methods where different equipment may be required or involved.

Other choices, although related to train operations and air brake systems, do not specifically meet the requirement for the AFM qualification process. For example, while having an automatic brake valve on the controlling locomotive is standard for many operations, it does not directly influence the air flow measurement necessary for the AFM. Similarly, a gauge at the front of the train may provide useful information but is not a requisite for the AFM