I've worked for non-union airlines (VERY profitable ones BTW) and strong union airlines (also profitable). Without a labor contract the rules can be changed at managements whim and at anytime -- AND THEY DO. With a contract, there are known rules that both management and the workforce must follow. Even then often times they break the contract and say "if you don't like it, grieve it" with an army of lawyer behind them.
In this industry, you'd have to be nuts to want to work for a non-union airline. I'm sure there are a couple of exceptions, but certainly not many.
[ 21 November 2001: Message edited by: Roadtrip ]