Training Tip: When ATC goes to zero

In ATC parlance, the facility had gone to “ATC zero” status—an unplanned closing that the existing contingency planning can’t prevent.

The interruption at New York Center was one of several instances in which positive coronavirus tests impacted air traffic control in March as the virus spread. The control tower at McCarran International Airport in Las Vegas also went to ATC zero status, with Class B airspace service unavailable and the terminal radar facility taking over from the tower. Four days into the closure, hundreds of flights had been delayed or canceled, with Southwest Airlines alone dropping about 500 flights from its schedule, according to a news report.

Before the coronavirus pandemic and an earthquake in Salt Lake City joined the list this month, equipment failures and natural phenomena like severe weather or flooding were known triggers for ATC facilities going ATC zero. In September 2014 an arson fire shut down the Chicago ARTCC when a reportedly suicidal contract worker lit gasoline-soaked rags near computer equipment in the facility basement. He pleaded guilty to charges in the incident and was sentenced to a 12-year prison term.

ATC-zero events are infrequent (434 systemwide in 2019, according to the FAA). If a portion of a facility is affected by a shutdown, the facility is said to be on “ATC limited” status, as was Indianapolis Center on March 19 in another event triggered by a coronavirus test. Far more common than ATC-zero or ATC-limited events are “ATC Alert” events, which numbered 1,765 in 2019.

The sudden and widespread impact of an ATC-zero scenario underlines the need for general aviation pilots to make regular and repeated checks of notams for airport closures, routing restrictions, and airspace service-level changes. Pilots can check for air traffic delays via the FAA’s ATCSCC website and selecting various products like current advisories.

ATC zero is not a time for taking advantage of the situation and adding to congestion—for example by making touch-and-goes at a busy airport like Midway International Airport in Chicago, a complication the FAA quickly addressed by imposing a temporary flight restriction, noted Rune Duke, AOPA senior director of airspace, air traffic, and aviation security.

As with the coronavirus itself, taking the necessary precautions in flight planning protects not just yourself, but all your fellow users of the airspace system as well.