What is the legal alcohol limit before operating an aircraft?

The legal alcohol limit before operating an aircraft is indeed set at a blood alcohol concentration (BAC) of 0.04 for pilots operating under CASA regulations. The choice that best represents the zero-tolerance approach in aviation is 0.02, which is associated with stricter policies that aim to ensure the safety of flight operations. This lower threshold underscores the fact that even small amounts of alcohol can impair a pilot's ability to operate an aircraft safely.

Although the more commonly known limit for driving a motor vehicle in many jurisdictions is 0.08, aviation regulations are more stringent due to the increased responsibility and potential consequences of pilot error. Therefore, even a BAC of 0.02 can indicate a violation of aviation alcohol regulations, making the choice of 0.02 aligned with the emphasis on safety in piloting.