Maybe a stupid question, but why fly them across the Atlantic? Can't they fly over continental US, or along the coast? It feels like it's the same, except any emergency is a lot less bad.

My best guess is that it's simpler for the pilots to focus on the plane because of less interactions with other planes and crowded airspace. The routes are probably simpler compared to domestic fights.

Emptier airspace

There are quite a few specific procedures unique to crossing the North Atlantic. Part of it has to do with the absence of radar and VHF comms requiring HF or satellite communications which pilots will otherwise never use. I'm sure Pacific crossings have their own peculiarities but I'm less familiar.

From the article:

> [...] these planes will largely be used for transatlantic flights, and that requires extra training compared to non-transatlantic operations.

Not a stupid question, the article is asking essentially the same question

> That brings me to another question… I understand the need for specialized training, but does anyone know what actually happens on these transatlantic flights that couldn’t be done in a simulator or classroom? Obviously these are all pilots who already know how to fly the plane, so it’s just transatlantic operations that they’re being certified on. So is it about interacting with air traffic control, understanding the North Atlantic Tracks, etc.?

Because they're flying over water. When an engine fails you have a lot fewer choices as to landing compared to flying over the US.

I'm sure some of it has to do with operating within the North Atlantic Tracks. Essentially when you lose radio connection you are placed in a slot with a specific speed, bearing, and altitude without the ability to be in constant contact with FAA radio guidance. - the airspace is more congested than you might imagine.

https://en.wikipedia.org/wiki/North_Atlantic_Tracks

expanding upon my above: this article is neat. https://aerosavvy.com/north-atlantic-tracks/