What is the maximum allowable blood alcohol concentration for operating an aircraft?

The maximum allowable blood alcohol concentration (BAC) for operating an aircraft is 0.04. This regulation is established by the Federal Aviation Administration (FAA) to ensure the safety of flight operations. At or above this BAC level, a pilot is considered to be under the influence of alcohol, which can significantly impair judgment, coordination, and reaction times—all critical factors for safe flying. The stringent limit reflects the aviation industry's commitment to safety, acknowledging that even small amounts of alcohol can affect performance. Hence, maintaining a BAC below this threshold is essential for pilots to perform their duties safely and responsibly.