American Airlines' filing for Chapter 11 bankruptcy reorganization is the latest after-shock to hit the industry in the decades following deregulation. American will continue to operate, but I can tick off a long list of airlines that have disappeared in my time as a flyer: Mohawk, Piedmont, Allegheny, Eastern, People's Express, Pan Am, etcetera, etcetra. The rapid growth of discounter Southwest (soon to merge with AirTran) continues to put pressure on the giants of the industry, and there are plenty of books that provide a primer on the turmoil.