I suggest you don't make a big deal out of it......just act as though you are getting on a bus. If you build it up as an Event she'll react accordingly.
Just "We're going to (wherever). When we get there, we'll....."
And, if hamgooster will forgive me, the very last thing you should do is tell her all about how lots of people are afraid of flying. 5-year old daughters are natural drama queens, and you would be giving her the material for her act.
To be fair,they're still drama queens at 15, 25, and 35. I'll have to let you know about 45, 55, 65, 75, 85, and 95 later.