I agree with all the other that say take the UPT slot if you can get it. It sounds like you want to be there for the right reasons and that means you're probably the type of person who will never regret your time in.

The most likely event to cause a global airline slowdown is a national security event that will cause military flying to increase. It is nice to have the option to pick up more military flying if you're furloughed.

Not a reason to join, but if you join the military for the right reasons, you'll want to go where the action is anyhow. Therefore, it is nice to know you have a buffer against a downturn in your civilian job.