When you are under the age of 21, you are not authorized to possess alcohol. This includes concealing it inside your checked baggage. Of course, the persons checking inside checked luggage are not verifying your age at the same time they are looking for your bag. Therefore, it is important that you do not bring alcohol onto a plane.
The Federal Aviation Administration (FAA) prohibits anyone under the age of 18 from flying with or without an adult. The only exception to this rule is if you are traveling with a licensed pilot who is at least 21 years old. Even then, your underage friend would not be allowed to drink any alcohol at all while on the plane.
If you are stopped by the police during a traffic stop and found to be carrying alcohol, even in small amounts, you can be arrested. Even if you are not drinking, merely having alcohol in your car can lead to jail time. It is best to avoid this situation by not drinking and driving or riding with someone who has been drinking.
Many airports will check the identification of passengers arriving with checked bags before allowing them access to the security checkpoint. If you are denied access to the security line because you cannot produce valid identification, there is nothing left to do but wait in line again once your bag has been screened.
It is best to leave assessing age verification methods to professionals.
In practice, if the alcohol is contained in your luggage the entire time, you are extremely unlikely to encounter any problems, especially if you are accompanied by an adult when traveling to the airport via check-in; it is not the case, for example, that your luggage would be tagged with your age, and...
...even if it did, there are no restrictions on what can be placed in your checked baggage. If, however, you are traveling alone or if you plan to fly with a young child where having alcohol on board could be problematic, then you should leave it out of reach of children.
The only other thing to note is that if you are traveling overseas, any laws prohibiting drinking on planes will apply once you enter the country so be sure to follow these instructions.
In most countries, it is permissible to bring alcohol on board an airline in your carry-on luggage or in baggage that will be checked before you board. To bring alcohol on an airplane, you must be of legal drinking age. The only exception is if the aircraft being flown has more than 8 passengers and neither you nor anyone else you are traveling with is under 21 years old. In this case, you cannot bring alcohol on board.
The only other requirement is that the bottle or container used to transport alcohol must be properly labeled as such. If it is not, then you could be in for a serious punishment when they search your bag at the check-in counter or during security screening.
Some countries may have additional regulations regarding the type or quantity of alcohol that can be brought on board. Before you travel, make sure you know what these restrictions are like in your country of residence.
Although it is not recommended, you may also want to consider carrying some form of liquor or alcoholic beverage containers in your hand luggage. This can be done in moderation as long as it does not exceed 3 liters (1 gallon) or 110 ml (4 oz.) of liquor or 20 ounces (oz.) or more of wine. Anything more than this and you should consider checking it in.
In California, state law forbids supplying liquor, including beer and wine, to anybody under the age of 21 on intra-state flights, hotels, and cruise ships in port. If our on-board crew has any worries regarding a passenger's age, they are taught to gently request evidence of age. The only type of evidence that is legal for passengers to possess is a driver's license or passport. If the company is concerned about underage drinkers, they may check the identification of everyone over the age of 18 as part of their pre-flight briefing.
The federal Transportation Security Administration (TSA) prohibits drinking on airplanes, including by minors. They do not care how old you are as long as you do not appear to be under the influence of alcohol or other drugs. A minor who violates this rule could be subject to detention or removal from the aircraft at the airline's discretion. Drinking on planes is dangerous because it increases your risk of suffering from alcohol poisoning. Alcohol poisoning can cause confusion, seizures, and death.
Drinking on planes is not recommended because it puts others at risk. The young, the elderly, and those with medical conditions such as diabetes, heart disease, and cancer should not drink any amount of alcohol anytime during their flight.
If you are going to drink on a plane, keep it to less than 3 ounces of wine, 1 ounce of spirits, or 8 ounces of beer per person, total, every 24 hours.
The FAA does not monitor in-flight drinking, but airlines do and normally adhere to the laws of the nation in which they are headquartered. For passengers, this means that regardless of the drinking age of the nation you're in, or en way to, a U.S.-based airline will not sell alcohol to any passenger under the age of 21. Alcohol sales on international flights is the responsibility of the carrier and data regarding drinking ages may not be readily available to travelers.
Some carriers have a social policy against serving minors while others don't care as long as you comply with your state's drinking laws. The best advice is to check with your carrier before traveling so there are no surprises when you get to the airport.
The only time I would recommend not drinking on an airplane is if you have an extreme allergy to alcohol. Otherwise, enjoy your beverage!