How does immigration/customs work for private jets?

[bordelond]

@Machine_Elf , this 2011 thread might interest you – the first 25 posts or so get to what you’re asking in the OP. I see that @Llama_Llogophile contributed several posts to that one, as well.

Can the uber-wealthy get into the U.S. undocumented via private-property helipads/airstrips?

(Inspired by the ongoing “Golfer Having a Hard Time Getting a Visa” thread in GQ) Let’s say Mexican multi-billionaire Carlos Slim holds a sybaritic Cinco de Mayo bash at a huge private compound near the resort town Playas de Rosarito, Mexico (near Tijuana). Slim invites a veritable whos-who of high-rolling moguls, enterntainers, and captains of industry & finance. During the festivities, Slim hits it off with one Bill Gates, of Microsoft fame. As they get to talking, Gates thanks Slim for lett…