I was in a long distance relationship for 4 years. Although it was very difficult, I think that they can work as long as both parties are committed to making the effort to keep communication open. It was very costly though so please beware.
I also found that when we were due for visits, because we had so much time to think about how we wanted the visit to go, sometimes it put unneccessary pressure on us to MAKE it perfect, as you know, life is not perfect so these times were trying. But as I said, keep communication open, be honest and faithful and this kind of relationship can work, but you will need to be patient and bear in mind that whether you are in a long distance relationship or not, relationships can be hard work... just ask yourself are you ready to commit to it for the length of your seperation??
Good luck.