Published Friday, Nov. 9, 2018 | 4:23 p.m.
Updated Friday, Nov. 9, 2018 | 8:23 p.m.
The Federal Aviation Administration is investigating after an air traffic controller at McCarran International Airport became “incapacitated” Wednesday during an overnight shift, according to airport officials.
Archived audio from the incident obtained by the Sun indicates several pilots became concerned when they sensed a female tower operator appeared incoherent. At one point, someone says the instructions being repeated back from the tower were erroneous.
“We have thoroughly reviewed the incident and confirmed that no safety events or losses of required separation between aircraft occurred, and there were no conflicts between aircraft on the airfield,” the federal agency said. “However, the FAA is very concerned about this incident and what occurred is not acceptable.”
The controller’s performance was normal when she began her shift at 10:06 p.m., said FAA spokesman Ian Gregor in an email. For unclear reasons, it began to decline about an hour later, deteriorating by 11:24 p.m.
Then at 11:47 p.m., the operator appeared “unresponsive,” Gregor said. Three minutes later, another operator, who had been on a break, entered the tower and took full control four minutes later, Gregor said.
Two controllers were on duty for that shift and breaks were allowed periodically, Gregor said.
Due to the incident — beginning Friday –—the FAA changed its overnight staffing policy, which now requires two controllers in the cab “until a certain time, based on shift periods and traffic levels,” Gregor said.
The incapacitated employee has since been restricted from directing air traffic, officials said.
In the air traffic control tower audio, the controller appears incoherent. “You’re coming in broken,” someone says to her.
“Is there somebody there that knows what they’re doing,” a pilot said. “Do you have anybody else up there,” another voice could be heard saying.
At one point, she continuously repeated instructions back to a pilot, providing the wrong number, even though the pilot continued to correct her.
Then she stopped replying. A voice can be heard saying that he’d heard through a “hot” microphone that somebody had walked in and asked if she was okay.
Eventually, another controller took to the radio and quickly began to provide clear instructions.
Gregor said pilots contacted staff at the base of the tower, who subsequently went to alert the controller who’d been on break so that he could relieve “the incapacitated controller.”
Through their training, pilots know not to land unless they have a clearance they’re comfortable with, Gregor said. “In this instance, some pilots opted not to depart or communicated with other aircraft on the common radio frequency,” he said.
Some pilots on the ground held their positions, while others proceeded with caution, questioning the controller while communicating with each other, Gregor said.
An airplane aborted landing and four airplanes inbound to McCarran were briefly held back, Gregor said. There were minor departure delays, he said.
“Our safety system is very interdependent and includes multiple layers of redundancies so there is no single point of failure,” Gregor said. “When one component fails, the risk increases but there are other processes and procedures in place to prevent an accident from occurring.”
“Safety is always the top priority in aviation,” Rosemary Vassiliadis, Clark County director of aviation, said in a release.
U.S. Rep. Dina Titus, a member of the House Subcommittee on Aviation, said in a statement that she was briefed on the situation and was awaiting further details, “but I find the initial reports deeply disturbing.”
“The safety of travelers is of paramount concern and I will work with the FAA and McCarran as this investigation continues to unfold,” Titus said.
