Mon May. 9, 2011 3:00 AM PDT
By Josh Harkinson of MotherJones.com
Last week, a computer glitch at Houston's air traffic control center caused dozens of flights to be delayed for up to an hour. Though it didn't put any planes in danger, the episode was another unwelcome bit of bad P.R. for the nation's air traffic controllers. In the past month and a half, five air traffic controllers were found to be asleep on duty, sometimes missing calls from pilots. Late last month, a mistake by a controller caused First Lady Michelle Obama's jet to fly too close to a military cargo plane.