I think the bigger concern is not what you weigh, its how you carry it. You may weigh 250, but are you fit and athletic?- can you get in and out of the emergency exits and fullfil your job requirements? The bigger concern- from the hiring viewpoint may be- will this guy be able to stay healthy and keep a first class medical? Most airliner cockpits are roomy (not so much for a CRJ... but normally...) so there is some room for the bigger guys. I have seen some pilots that do make me wonder though...