ATC-Zero: What That Means for Business Aviation

 - March 24, 2020, 3:35 PM

This story is part of AIN's continuing coverage of the impact of the coronavirus on aviation.


During a webinar held today by the National Business Aviation Association (NBAA), the important question that listeners wanted answered had to do with speculation that U.S. airspace would be shut down due to the coronavirus crisis. The webinar—“When COVID-19 Causes 'ATC-Zero' Disruptions–Planning Considerations”—was recorded and is available on the NBAA website.

The term ATC-Zero means that an FAA air traffic control (ATC) facility can not provide published ATC services. FAA Order 1900.47 explains ATC contingency plans and includes information about what happens during ATC-Zero events. A historical search on the internet revealed the use of the term after the 9/11 attacks, but it is not known if ATC-Zero was used prior to that.  

The webinar’s hosts—NBAA COO Steve Brown; Heidi Williams, NBAA director of air traffic services; and David Villegas, an NBAA air traffic services specialist—reassured the audience that a national airspace shutdown is not likely.

“There is little need to talk about that kind of shutdown on a national basis,” said Brown. While there have been some “ATC-Zero” events or closures of air traffic control facilities or elements in those facilities due to Covid-19, he said, “The FAA has taken steps to prevent the spread [of the virus]. We have a robust system with many backups, and the FAA Administrator has communicated to us in the last day that there is no ongoing discussion about [a national airspace shutdown].” In any case, he added, a significant decline in flying means that “the system is well-staffed, given the lower volumes of traffic.”

So far, ATC issues related to the virus have hit six FAA facilities, according to Williams. But these events don’t always result in the closure of an entire facility, and there are three levels of impact: limited, alert status, and ATC-Zero (complete shutdown).

Today, the tower at Republic Airport in Farmingdale, New York, remains closed, and the airport is notamed for no touch-and-go landings or practice IFR approaches until April 5.

The tower at Las Vegas International Airport closed (ATC-Zero) on March 19 but was expected to open today, while Chicago Midway’s tower reopened in the middle of the day. La Guardia Airport suffered some limited operations, but its tower is still operating. Indianapolis Center is in alert status and closed some airspace, rerouting traffic around the closed area. New York Center experienced some alert status impacts over the weekend of March 21 to 22.

“We’ve seen an organized job on the FAA Command Center floor,” said Villegas. “They’ve done a considerable job of [maintaining] continuity.” He went on to explain that the FAA has contingency plans for issues that might force closure of facilities or portions of facilities. FAA personnel rehearse and use these plans so they are prepared for eventualities such as weather events, a fire, or now, the coronavirus.

What the contingency plans cover is how to keep traffic flowing if, say, a terminal radar (Tracon) facility or tower or center needs to be evacuated or part of a larger facility needs to shut down. If a tower closes, for example, then traffic will be shifted to the Tracon. If the center shuts down entirely, its traffic could be shifted to Tracons or adjacent centers. And towers could take over some low-altitude Tracon traffic while the rest is moved to the overlying center.

“This is well-planned for by the FAA,” said Brown. “The protocols are known and they are rehearsed routinely to manage temporary outages.”

There is an issue related to Covid-19, however, and it can cause longer outages. For example, a local or state government might require a 14-day quarantine of a facility after someone tests positive for Covid-19, preventing that facility from reopening right after cleaning. This might require a longer period of shifting traffic to adjacent facilities and it could mean pilots need to prepare to operate at airports that have become non-tower facilities.

Thus, advised the trio of air traffic experts, “be prepared.” Pilots must plan before departure for how to operate safely at non-tower airports.

Generally, ATC Tracon and center facilities will continue accepting traffic, even in a case where traffic is shifted to an adjacent facility. However, Williams warned, there have been cases recently where traffic was diverted before reaching the terminal environment.

“Make sure you are fueled for your alternate, but [also know that] you might be diverted outside the center’s airspace. Think about that if you’re traveling somewhere where there is a potential for a facility to be impacted.”

If the destination airport’s tower is closed, she added, “We’re all pretty familiar with that, about keeping our ears open and listening for other traffic. Be sure you understand the layout of the airport, the taxi diagrams, and heeding other traffic.” Pilots flying at Las Vegas, Chicago-Midway, and Farmingdale have been reverting to making radio calls about taxiing, crossing runways, taking off, and arrivals and landing on the common traffic advisory frequency (CTAF).

While some of these airports have notams warning pilots not to do touch-and-go landings or practice approaches, one pilot was observed to be doing touch-and-goes at Midway in a Cessna 172. “Like at MIdway,” she said, “it is probably not the best idea to do touch-and-go operations. You can and are allowed to, but does it make sense and is it best for the rest of the system? These are questions we should ask. It’s busy enough with mixed traffic, air carriers, business aviation, and [light aircraft]. It’s important to exercise good judgment.”

One unique feature of U.S. national airspace is that unless the federal government closes the airspace, as was done after the 9/11 attacks, much of the U.S. airspace system remains open to VFR traffic when ATC-Zero happens. And for business aviation, flying VFR should be part of contingency planning, Brown explained.

ATC might be able to give pilots VFR flight following services below FL180 if they aren’t able to be on an IFR flight plan, especially considering some areas might not be so busy these days. But in a case where ATC is diverting traffic around a closed center sector, it’s likely that the controller has a better view of the big picture. “Maybe it’s better to remain [on the IFR flight plan] and do the divert,” Williams said, instead of canceling IFR and going VFR.