Are you sitting there refreshing the plane route app thing?
I’m saying this kindly as a fellow anxiety sufferer.
STOP IT!!!
You are not helping yourself. Say that worst case scenario, something does happen with his plane. It’s hugely unlikely as other posters have said, but it’s not completely impossible. How will sitting there now refreshing the plane app, worrying about it, keeping yourself awake and feeding your anxiety, change anything? It won’t. You watching the plane app won’t make his flight any safer than it already is (pretty safe). It will make you feel awful though.
Remember your CBT. Did you learn about the worry tree (attached)?
You need to take control of your anxiety rather than let it control you. Close the plane app. Focus on something else - whatever your distraction or coping techniques are - put on a mindfulness app thing, take a bath/shower, listen to music and clean something, get out a craft project, do an exercise video, reorganise your sock drawer..... whatever practical, physical task that keeps you focused on the here and now and your current real experience, and distracts you from the catastrophising thoughts & associated feelings your anxiety is trying to put you through.
Managing anxiety is about learning to tolerate these thoughts yourself - us reassuring you about the safety of his plane isn’t actually helping you - you know that already.
It is possible for you to manage this! You can do it! 
