I've had two transatlantic relationships -- one that worked and one that didn't. The one that didn't work had more challenges -- no VoIP at the time, cell phones still very expensive, language differences which hindered communication (his English was very good but not on the level where you could talk in subtleties or nuances) and, perhaps biggest of all, no discernible end in sight.
The one that worked we've been able to stay in touch every day through email, VoIP and texts, we're both native English speakers (though as a Brit and an American it's debatable whether we share a common language ), I've been able to see him very regularly thanks to my airline job, and we knew from the very first that there was a finite end to our distance.

A year after we met and I've given up the airline job (heresy around here, I know) and in five days' time will be getting on a plane for my new life in the UK.

Having a goal set down, a time when one of the two (or both) will move so you'll be together is, IMHO, critical. Of course there's trust and communication, but if you don't see a relationship going anywhere it's hard to justify the hardship (emotional, financial and otherwise) of an LDR.