Federal and airport authorities said Friday they're investigating why an air traffic controller became incapacitated and went silent while working a night shift alone in the tower at the busy McCarran International Airport in Las Vegas. "No safety events occurred during this incident," the FAA said in a statement on what officials said amounted to a 40-minute span during which the female controller slurred words, then apparently lost consciousness shortly before midnight Wednesday. "An air traffic controller at the Las Vegas tower became incapacitated while on duty," the agency said. It didn't ID the controller or the cause of her incapacitation. The airport's director issued a statement saying initial findings echoed the FAA's, per the AP. Five inbound aircraft were airborne during the incident, and aircraft on the ground held positions or communicated between themselves, the FAA said.
Air traffic recordings show commercial airline pilots having trouble understanding the controller during radio communications about approaches to land, clearances to take off, and taxiing directions. Some began talking between themselves about something being amiss. At one point, the controller sounds sleepy and apologizes, saying she's "choking a little bit." Minutes later, she misstates an aircraft's call numbers. Finally, her mic opens to the sound of coughing and grunting. She doesn't respond to a pilot's inquiry before the sound of a male voice is heard in the room asking if she's all right. Officials said a male controller who'd been on break was summoned to return to the tower; paramedics responded. The FAA said the woman was put on administrative leave, and the agency ordered two controllers to be in the tower during busy hours. (Read more Las Vegas stories.)