Check with your pump manufacturer about their advice regarding metal detectors/x-ray machines at airports. There is supposedly a risk these things can knock out an insulin pump, although the only evidence for this I've seen is a news report of teenage girl on a summer camp away from her parents whose insulin pump magically broke on the way home (as opposed to the probably far more likely prospect she just wrecked while away). But it's better to check just in case.
In terms of your BGs - it's only 3 hours or so, so I wouldn't stress it too much. Things to bear in mind are that you'll be sat down for three hours so potentially you'll be doing less physical activity. If you're flying on the sort of airline that gives you a meal, most of the meals are loaded with carbs (by the way, the 'diabetic' meal is even worse!). So your BG might be up. On the other hand, you're lugging a suitcase, which could be more activity than you're used to, and if you're anything like me you'll have to run to the gate in a mad panic. Then you're also likely to be more stressed than usual, which could make your BG go either way.
So the short answer is "dunno, it depends on you." The longer answer is "as long as you've got your test strips, insulin and some glucose with you, who cares? You'll be able to fix any problems straight away."