We fly now, after years of driving and it is so much easier. I didn't really like to fly at all but it gets easier, the more you do it. My ds had a fear of heights and was an anxious flier but now it doesn't bother him. The last bumpy flight we had, I kept telling myself that I never heard of a plane crash because of turbulence. Maybe show him some you tube videos on what inside a plane looks like. Maybe ask the doctor if he can take some Benadryl, if it relaxes him. Good luck.