Lessen external stressors by arriving at the airport with ample time to get through security and to pick up your favorite healthy snack to bring on the plane for comfort.
Takeoff and landing
Listening to an audio book or music while taking off and touching down helps block out potentially irksome sounds and redirect your thoughts.
Fear is more likely to gain a foothold when you're alone. Strike up a conversation with the person sitting next to you, whether you know them or not.