Mo. Rev. Stat. § 577.015: Operating an aircraft while intoxicated — penalties.

1. A person commits the offense of operating an aircraft while intoxicated if he or she, while in an intoxicated condition, knowingly operates any aircraft or knowingly acts as a copilot, flight engineer or flight navigator for an aircraft while in operation.

2. The offense of operating an aircraft while intoxicated is:

(1) A class C misdemeanor;

(2) A class A misdemeanor if the person has previously been found guilty of the offense of operating an aircraft while intoxicated or with an excessive blood alcohol content, or any offense committed in another jurisdiction which, if committed in this state, would be the offense of operating an aircraft with excessive blood alcohol content or while intoxicated.