What should be inspected regarding airlines during a pre-trip inspection?

During a pre-trip inspection, it's crucial to check for cracks, leaks, or abrasions on the airlines because these issues can significantly affect the performance and safety of the braking system. Airlines are responsible for transporting air throughout the air brake system, and any damage such as cracks can lead to air loss, which compromises the braking power and could result in brake failure. Leaks not only reduce the effectiveness but can also lead to increased wear on components. Abrasions may indicate that the airlines are rubbing against other parts of the vehicle, which can cause further damage over time. Therefore, this inspection ensures that the airlines are in good condition and functioning properly, ultimately contributing to the safety of the vehicle and its operation.