At what blood alcohol concentration (BAC) is a pilot considered under the influence?

A pilot is considered under the influence when their blood alcohol concentration (BAC) reaches 0.04%. This standard is set by the Federal Aviation Administration (FAA) and aligns with the legal limits for operating aircraft. At this level, impairment can begin to affect a pilot's performance, judgment, and reaction times, which are all critical for safe flight operations.

The 0.04% BAC limit reflects a cautious approach to ensure aviation safety, accounting for the unique responsibilities and decision-making required of pilots compared to other professions. While higher BAC levels can lead to more pronounced impairment and legal consequences, the 0.04% threshold specifically indicates when a pilot's ability to operate an aircraft safely is compromised.