Southwest's Problem: Its Planes Fly Too Much

Southwest Airlines may be a victim of its own efficiency. The airline's much-touted short-haul operations require each plane to fly an average of six times a day, and the stress of all those landings and take-offs may be partially to blame for the cracks found in some of their older 737s, the LA Times reports. The plane forced to make an emergency landing in Arizona, for example, is 15 years old.

"The Boeing 737 is very reliable and efficient, but this one is an aging aircraft," says one aviation consultant. "It could be making 2,200 flights a year. Maybe more than that." A safety expert agreed, likening it to "blowing up a balloon and letting the air out over and over." He called for more frequent and rigorous inspections, noting that the airline was once fined $7.5 million for failing to inspect its planes, and that in 2009 one plane had to make an emergency landing thanks to a football-sized hole in its fuselage. (More Southwest Airlines stories.)