Being in a plane that actually crashes, bursts into flames (with you inside) and seeing many of your best friends perish in that instant would be a permanent block for me too.
People get in car wrecks all the time and watch their fellow passengers die right next to them. Most of them drive again - usually as soon as they are able to. And there's a pretty high chance that they will be involved in another accident in their lifetime. The odds of being in a plane crash are EXTREMELY small. The odds of being in 2 are damn near 0.
Not arguing that this isn't incredibly traumatic for Travis, but when you think about what I just said - you gotta admit it's something he should be able to overcome. And I hope he does.