What should you do if you board a plane with something (drugs, guns etc) legal to carry at origin and destination, but the flight is diverted to somewhere it is illegal?

The situation you described is called “Force Majeure”, when due to unforeseen circumstances you are forced to divert your voyage. This happens quite a lot with ships at sea, they may have a mechanical breakdown or a medical emergency. This forces them to go into port, unplanned. Working offshore on an oil platform, I have seen this with helicopters, they are forced to land on our platform, due to a mechanical problem.

Underway your ship or plane follows the law of it’s home port, an American ship follows American law, but when you arrive at a foreign port you follow the local law. This applies to “Force Majeure”, once we were diverted due to an engine problem into Jeddah, Saudi Arabia. The local police boarded and searched our ship for pornography and liqueur. The liqueur was locked up, but all the pornography was seized, even though that was legal in the U.S.

So in answer to your question, yes if found they will seize any illegal drugs, but you probably won’t be charged, since it’s unlikely you would deplane or leave the immediate area of the airport.

Force majeure – Wikipedia

I would prepare for a long stay in the airport until you get on a new flight to your destination.

(I’m not a lawyer, and this is in no way legal advice.)

Airports are kinda weird places in that people always need to make connections and travel through them, even if they’re not always going to the country the airport is in. All foreign travelers (and goods) need to pass through customs before they’re allowed to enter the country – but not necisarily to enter the airport itself.

If there was bad weather, or the plane needed an emergency fuel stop, then everyone stays on the plane. The doors are never opened, and nothing is ever removed from the plane, or left at the airport. Just like a sealed package, the plane lands, and the plane takes off again – no more, no less then what was on the plane enters or leaves the country.

If there was a longer delay, and everyone had to leave the plane….

Assuming that your airplane lands at an airport with customs facilities, if you had something illegal, then I would assume that you would not go through customs to enter the country, and would just stay within the confines of the customs area at the airport. (Anyone who went through customs to get IN to the country would probably have to pass back through to get OUT of the country again – so you couldd potentially be searched twice.)

Depending on what it was, and how illegal it was, the customs people might be able to hold it for you, or they might confiscate it. They could also contact your home country – if the item was illegal to export from your country, you could be in big trouble anyways. On one hand, they know that the plane landed there by accident. On the other hand, there are certain things they can’t let into the country. Drugs I would imagine would be a big problem. I highly doubt they would let you in to the country with them. A gun I could see them putting in a safe or something to hold for you until you left. (This would be one of those unintentionally illegal things.) Ivory or something like that they might just ignore, since you weren’t planning to be in their country in the first place, and they’ll just let it be someone elses problem later.

Airports are kinda international places. So as long as you dont cross customs and wait for plane to take off and land at original destination it will be fine.

you can also give those items to customs and they will destroy those items for you.

it is forbidden to cross customs part without telling them what you bring.

Well airlines follow federal law. Meaning even if you’re traveling between Colorado and Massachusetts we’re weed is legal, it still would be federally illegal since its banned under federal law and you would be transporting across state lines which would be trafficing. As far as firearms , if you had the proper license for both states and you were diverted to a non legal gun state, I think you would be fine seeing as you’re gun would have to be in you’re checked luggage anyway which you wouldn’t even have access to if you were diverted.

Get rid of it. In NYC, it is illegal to have an unregistered hand gun in your luggage regardless of the fact that it is legal where the flight originated and at the intended destination.

If you are carrying citrus, for example while travelling from Canada to Mexico, it will be seized at Customs.

Hmmm Drugs, Guns… my guess is that you are for the legalization of Marijuana or are attempting to show how unfair the laws are. Or you are against gun control and trying to demonstrate the same.

Now first off I’m assuming you are talking about the US. The Federal regulations are very clear about guns and how they are to be transported via air and in baggage. So in that case leave it where it is and do not leave the airport. You should be OK. The same goes for checked baggage. It will continue on to your destination if you are deplaned.

On the other hand federal law is also very clear Marijuana is a Class 1 drug the same as LSD and Ecstasy. You are breaking federal law no matter where you are in the US. It is just common sense you should never carry illegal drugs on you. Carrying them in an area where you can be stopped and searched with out a warrant and there are an abundance of drug sniffing dogs also would show a lack of common sense. Don’t do it.

If it is some other legally prescribed substance do not carry it loose but rather in it’s labeled container with your name on it. I’m assuming you got on the plane with legal and accurate identification that would match the name on the RX. You should be OK.

Have a great day and remember smoking dope impacts your judgement. Legally carrying or owning guns does not. Smoking dope and carrying guns is just stupid. So is drinking and carrying guns. Owning a weapon and transporting it according to federal regulations is a constitutional right. Smoking dope is not.