The last legacy airline to have avoided bankruptcy filed for Chapter 11 earlier this week. Megan McArdle focuses on the company's intractable labor disputes:

[W]hen there are three or four unions--pilots, flight attendants, mechanics, and baggage handlers--things get complicated. All of those groups are completely necessary to make sure that the plane gets in the air. If one of them doesn't show up, you lose all the money on every seat.