Hank Krakowski, chief operating officer of the Air Traffic Organization, is resigning after reports of controllers sleeping on the job. A nationwide search is being conducted for his replacement, but the job will temporarily be filled by David Grizzle, the chief counsel for the FAA. A plane headed for Reno, Nevada, was forced to land unassisted Wednesday morning when an air traffic controller was sleeping on the job and out of communication for nearly 16 minutes, though no injuries were reported. It was the second such incident this week alone, and it follows on the heels of several others. The FAA announced on Wednesday that it will be adding a second controller to work the overnight shift at 26 airports around the country. Almost five years ago, there was a fatal crash in Kentucky in which a controller was working alone and likely suffering from fatigue, though blame for that incident was ultimately placed on the pilots.