If you have a friend in the USA who owns a lot of land that is suitable for landing a plane, and you own a private jet with 2 pilots in Norway, can you take off in private property without notifying anybody on what you have on the plane and where you are going or anything like that and fly to the USA and land on the property of your friend? Is that legal to do?
Yes, it is possible to land an airplane in the US at a private airport when you have taken off from a foreign airport.
No, you may not do it legally.
Doing this is a federal crime. Since you are smuggling something, you may not care about the legality. When you are eventually caught, you will go to prison. Your assets will be confiscated by and forfeited to the government. And once you are released from prison, you will be deported and blacklisted from entering the US ever again. Your gold will not be returned to you.
It is not worth the risk. Especially when the gold is worthless unless you can convert it to money. You can’t do that legally either (more prison time). Even money gotten through illegal means is forfeited to the government.
No matter from where you takeoff, nor in what country your aircraft is registered, if you cross the US Air Defense Identification Zone, you have to land at an Airport of Entry before proceeding elsewhere. You have to declare any goods or monetary instruments (even gold) you are transporting to Customs and Border Protection located at the AOE. There are trade laws, aviation laws, customs laws, banking laws, tax laws, Anti-terrorist laws, etc. that you will be violating if you do not.
In general*, any time people or cargo enter another country, they must do so at a designated Port of Entry, i.e. where customs and immigration officers are stationed. This is true regardless of whether traveling by land, sea or air. Trying to enter other than at a PoE is usually a serious crime, and in the case of flying without a proper flight plan, may even get you shot down.
In the US specifically, you can request (for a fee) that these officers meet your flight at an airport other than a designated PoE, which is a really convenient perk for GA pilots. As far as I know, they will only agree to do this at public airports, and if you ask about a private airport such as your friend's farm, they'll tell you to land at a public airport first to legally enter the country and then continue to the private one as a domestic flight.
(* Open border agreements like Schengen are an obvious exception.)
Think about how your question is fundamentally different from this one:
If you have friend in the USA that owns a lot of land that is suitable for landing a plane, and you own a private jet with 2 pilots in Colombia, can you takeoff in private property without notifying anybody on what you have on the plane and where you are going or anything like that and fly to USA and land on the property of your friend? Is that legal to do?
But would anybody notice that I'm transferring cocaine if the cocaine is hidden and I put the cocaine there long before the actual travel. And would I need to arrange customs to come to me? And how would I do that. This is just me wondering if this is actually possible.
I'll bet you can answer this question all by yourself without even consulting additional sources. If not, you can probably put on your Customs and Border Patrol hat and ask yourself: "What would I think of a covert flight of this nature crossing into my airspace? It's probably a totally cool, totally legal flight with no contraband on board. I'm gonna go ahead and do nothing."
No, your plan could never succeed. You could not file a legal flight plan since your plan has no provision for landing at an appropriate port of entry for customs and immigration clearance. If you attempt to make the flight without filing a flight plan, you would necessarily need to transit the North American ADIZ (Air Defense Identification Zone).
The map below does not show the Alaska zone, but rest assured it also exists - there is no way to cross into the north american land mass without being detected.
Any aircraft flying in these zones without authorization may be identified as a threat and treated as an enemy aircraft, potentially leading to interception by fighter aircraft.
With no defensible justification for your presence in that airspace you would be treated as a hostile aircraft and dealt with as such.
I'm certain there will be problems with this, because this is very much the way smugglers move goods across a border without letting customs authorities inspect it.
If you cross from international airspace to American, without a flight plan, at the very least you'll be directed to land at a recognized airport for customs, and if you don't respond to attempts at contact, it's possible warplanes might be dispatched to intercept you -- this could even go as far as a shoot-down, in the worst case.
Even if you "aren't smuggling," if you have anything of value on board, this kind of flight is smuggling. It will also run afoul of immigration laws, if anyone on board isn't an American citizen (and will be seen as suspicious in that regard even they are).