What is required of a crew member before the end of a "required rest" period regarding alcohol consumption?

The requirement for a crew member regarding alcohol consumption before the end of a "required rest" period is that they cannot consume alcohol within 8 hours. This standard is crucial for ensuring that crew members are well-rested and alert, ultimately contributing to the safety of flight operations. The 8-hour rule is commonly referenced in aviation regulations to mitigate the risks associated with pilot fatigue and ensure that crew members are fit for duty when they report for their shifts.

By adhering to this guideline, crew members can ensure that they have adequate time to metabolize any alcohol consumed before they take on responsibilities that demand high levels of concentration and physical capability. This standard helps maintain not only individual safety but also the safety of passengers and crew alike.