Originally Posted by Adlerdriver

Very acceptable, especially in the US.

The problem is that option 4 is not going to be any pilot’s “go to” solution for communication with ATC, especially within the US where the easiest option (VHF radio) is so common and reliable. It’s also not a particularly expedient option in a time critical situation like that in your book. If I were in Cleveland center’s airspace and my choice was to dig into my enroute chart and try to find their phone number or just key the mic and talk to them, I’ll choose the radio every time. So if you’re going for realism, I don’t think the satphone is going to play well, especially if all the pilot wants is a vector over a uninhabited area. If he’s going to talk to some nuke expert to figure out if he should cut the blue wire or the red one, that’s where the satphone would make more sense. Just my .02.