I went through the same stuff a while ago. I still remember how my mum was worried about dying in the plane crash, and she even said out loud that I needed to be buried close to home so she could visit me. Mums, they always be mums.
So, based on what I went through, I can say that you should tell them about how safe military flying actually is, with lots of good training that pilots go through. Talk about how this training teaches you to be disciplined, to lead, and to really understand the technical side of things. Also, I want to share how loving planes and being good at computer stuff can come together for lots of different job options. This way, they can see that flying isn't just about being up in the air; it can lead to many other cool careers.