FaceTime says check number

So my dad flew from California to Florida for a trip and turned on his iPhone 5 to airplane mode but when he turned it back on, he started having problems with FaceTime and iMessage. When he tries to iMessage it turns up green for an SMS instead of the blue and when he tries to FaceTime it says to check the number because the number is incomplete. At first we thought it was a problem just between him and I since I am currently in England, but he checked with another family member back in California and it didn't work for them either. We never had problems when he was in California. Anyone know what we can do to fix it?