The Federal Aviation Administration responded this week to recent problems with air traffic controllers sleeping on the job by announcing changes to scheduling practices to allow controllers more time for rest in between shifts. “We expect controllers to come to work rested and ready to work and take personal responsibility for safety in the control towers,” said secretary of transportation Ray LaHood in a statement. “We have zero tolerance for sleeping on the job.” The new rules, which will be fully in effect by the end of this week, include: Controllers now will have a minimum of nine hours off between shifts (up from the current minimum of eight); they no longer will be able to swap shifts unless they have a minimum of nine hours off between the last shift they worked and the next; they no longer will be able to switch to an unscheduled midnight shift following a day off; and FAA managers will schedule their own shifts in a way to ensure greater coverage in the early morning and late night hours. Recent close calls due to lapsed coverage in a control tower resulted in the resignation last week of Air Traffic Organization head Hank Krakowski. David Grizzle, FAA’s chief counsel, has assumed the role of acting COO.