Can you check the city select at the gate? I was reading that over 20 lbs you have to check. I am also concerned about them breaking it especially with the car seat adapter still on it. I might just take my smaller chicco stroller and wear DS so DD can sit in the stroller. I am traveling along only an hour flight.
Re: city select and airplanes
My DH was a little psycho about ours the first time we traveled with it and he bought the travel bag. We have traveled with it twice, put it in the travel bag twice, gate checked it twice, and both times, it has suffered minor (but made me angry) damage. The last time the travel bag (which is really durable) had a hole torn in it (how does that happen). The airline (we flew the same one both times) and they refused to help.
My sister had a different stroller suffer major damage on a different airline and they did nothing (her stroller was damaged so badly that it was rendered useless). Good luck!