Baby's first flight

Feeling a bit shaky about taking the little one on his first flight trip.
First of all, how can I fit all his stuff (and mine) in one suitcase??!!!
After having the packing sorted out, a bunch of questions poping up in my head.

• What if he going to be cranky through out the trip?
• Or do a big stinky poop just after we've boarded?
• Or decide that he doesn't like sitting in the baby carrier?

Another thing I'm horrified about is the security at Oslo airport on the way back. The thought of having to pick up the luggage and check it in again and then go through security again make me wish that I was an octopus!