Yet another air traffic controller has been caught sleeping on the job, the Federal Aviation Administration said on Saturday, the fifth such case to be revealed since late March. The controller was napping at a high-traffic regional hub, officials said, but didn’t miss any calls from airplanes. Still, the case has prompted an emergency overhaul of traffic controllers’ schedules, with the FAA due to roll out new rules in the next 72 hours. Last week, single-staffing during overnight shifts was ended, but more changes are on the way. “We are taking important steps today that will make a real difference in fighting air traffic controller fatigue,” said FAA administrator Randy Babbitt in a statement.