Apparently a class C misdemeanor in Missouri.
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.
577.016. Operating an aircraft with excessive blood alcohol content — penalties. — 1. A person commits the offense of operating an aircraft with excessive blood alcohol content if he or she knowingly operates any aircraft or knowingly acts as a copilot, flight engineer or flight navigator for an aircraft while in operation:
(1) With four one-hundredths of one percent or more by weight of alcohol in his or her blood; or
(2) Within eight hours after the consumption of any alcoholic beverage.
2. As used in this section, percent by weight of alcohol in the blood shall be based upon grams of alcohol per one hundred milliliters of blood or two hundred ten liters of breath and may be shown by chemical analysis of the person's blood, breath, saliva or urine. For the purposes of determining the alcoholic content of a person's blood under this section, the test shall be conducted in accordance with the provisions of sections 577.020 to 577.041.
3. The offense of operating an aircraft with excessive blood alcohol content is:
(1) A class C misdemeanor;
(2) A class A misdemeanor if the defendant has been found guilty of operating an aircraft with excessive blood alcohol content or operating an aircraft while intoxicated or any offense committed in any jurisdiction which, if committed in this state, would be the offense of operating an aircraft with excessive blood alcohol content or operating an aircraft while intoxicated.
And a felony of the third degree in Florida.
860.13 Operation of aircraft while intoxicated or in careless or reckless manner; penalty.—
(1) It shall be unlawful for any person:
(a) To operate an aircraft in the air or on the ground or water while under the influence of:
1. Alcoholic beverages;
2. Any substance controlled under chapter 893;
3. Any chemical substance set forth in s. 877.111; or
(b) To operate an aircraft in the air or on the ground or water in a careless or reckless manner so as to endanger the life or property of another.
(2) In any prosecution charging careless or reckless operation of aircraft in violation of this section, the court, in determining whether the operation was careless or reckless, shall consider the standards for safe operation of aircraft as prescribed by federal statutes or regulations governing aeronautics.
(3) Violation of this section shall constitute a felony of the third degree, punishable as provided in s. 775.082, s. 775.083, or s. 775.084.
(4) It shall be the duty of any court in which there is a conviction for violation of this statute to report such conviction to the Federal Aviation Administration for its guidance and information with respect to the pilot’s certificate.