A person cannot act as a crewmember of a civil aircraft if they have consumed alcohol within the past:

The regulation concerning alcohol consumption for crewmembers of civil aircraft is clearly defined for safety reasons. The rule stipulates that no person may act as a crew member of an aircraft within eight hours of having consumed any alcoholic beverage. This is known colloquially as the "bottle to throttle" rule. The reason for this strict limitation is to ensure that pilots and other crew members are fully alert and capable of performing their duties without the impairing effects of alcohol, which can diminish cognitive function, reaction time, and overall situational awareness.

This eight-hour limit is crucial for aviation safety, as it helps to mitigate the risks associated with potential impairment. The emphasis on this time frame underscores the aviation industry’s commitment to maintaining the highest standards of safety and ensuring the well-being of both crew and passengers. Adjusting this limit to a shorter period could potentially compromise aviation safety, which is why it is crucial that crewmembers adhere to the eight-hour guideline following any alcohol consumption.