ATC Zero: What Happens When COVID-19 Forces Air Traffic Control Facilities To Close

On March 21, 2020, I was working at Washington Air Route Traffic Control Center (ARTCC). As I returned from break, the Shenandoah (SHD) and Wahoo (WAH) sectors, which are side-by-side sectors owning Flight Level 340-600, were getting busy. I offered the SHD Radar Controller a break, but she passed. I relieved the SHD D-Side (an additional controller at the sector who, when it gets busy, performs landline coordination with other sectors and facilities). As I was plugging in, I was told New York ARTCC just went ATC Zero and to stop all incoming aircraft from the adjacent sectors.  

ATC Zero is when a facility is unable to provide air traffic services or "zero services." Every facility has Contingency Plans in place for if/when these situations happen. One of the first steps in this is to shut the adjacent sectors/facilities off.  This puts them into a "No-Notice Hold," meaning the other sectors can hold their airplanes or do whatever they want, but they cannot accept any handoffs allowing any aircraft into the affected airspace.

After I received the briefing and assumed the SHD D-Side position, I called the three sectors around us and put them into the hold. A couple minutes later, the BADEN sector in Atlanta ARTCC called and shut us off. They couldn't take any more aircraft due to the number already inside their airspace. At that time, I had three aircraft in handoff status to them.

While I had them on the line, I asked if they could take the one aircraft at FL410 heading southbound direct Pulaski (PSK). The reason why I asked about that particular aircraft is we had another aircraft headed northbound at FL410 plus an aircraft headed westbound underneath them at FL400, all in the same general area.

I knew the aircraft I asked him about was a Boeing 737-800, and its max certified altitude was FL410. That means I couldn't climb them to put them into a holding pattern. We would need to be spot-on with vectoring to avoid Atlanta ARTCC's airspace while maintaining separation from our traffic. Luckily, the Atlanta controller agreed to take them, and they were able to continue on their route.

I switched off the landline and told the radar controller what I had just coordinated. Most of the aircraft in our sector were headed southwest bound toward Atlanta ARTCC. Being in a no-notice hold situation, the highest priorities are the aircraft closest to the boundary to the next sector.

When a controller is put into a No-Notice Hold, it raises our workload significantly. We have to issue holding instructions to all of the aircraft affected, which takes time. Once all the holding instructions have been issued and the aircraft have entered the holding patterns, our workload goes down significantly, usually lower than before the hold. Once aircraft are established in the hold, it is fairly easy to peel them out in an orderly fashion.

The radar controller started putting aircraft in Present Position Holds. The first two aircraft took their holding instructions and entered the holding pattern. The radar controller told the next aircraft, "I have holding instructions, advise ready to copy." This aircraft departed the Washington, D.C., metro area and was flying to Texas. The pilot responded by asking if we actually meant the holding instructions for them. The radar controller told them, "affirmative, New York Center just went ATC Zero, and due to saturation, I have to put you into the hold, advise ready to copy." Instead of taking the holding instructions, the pilot said, "We are currently 839 miles from our destination, and New York Center is behind us, why do we have to hold?"

Now, I have to admit, this is one of my pet peeves. I completely understand when a pilot asks us to confirm what they heard was correct. However, the minute pilots start arguing after we have confirmed the clearance or statement, well, that is when it becomes frustrating. This happens most often with holding patterns. I have never seen a pilot talk a controller out of putting them into the hold, so arguing is a waste of time. Whenever we, as controllers, get put into the hold by another sector or facility, we usually have to issue holding instructions to several aircraft. So we don't have the time to waste with a back-and-forth about why they are going into the hold after we've stated the reason.

If you need to declare an emergency or need to divert for some reason, then, by all means, please tell us. If you have a special circumstance, such as being low on fuel, just make a simple statement as you read back your holding instructions stating you only have about xx minutes (e.g. 15 minutes) to hold before you will need to divert. That type of information is valuable as we can sometimes work an exception out for the special-circumstance aircraft. Otherwise, please take the holding instructions and wait for things to slow down on frequency. Once they slow, feel free to ask your questions.

The radar controller responded to the pilots saying that yes, New York Center is ATC-Zero, but the next sector put us into a No-Notice Hold due to saturation from the backup of traffic. Advise when you're ready to copy holding instructions. The pilot came back and said, "Okay, hold on." I was mystified that they didn't even grab a pen during the back-and-forth. Eventually, they received their holding instructions and entered the hold.

Whenever a sector gets "shut off" and the controller has to put aircraft into holding patterns, they are drastically reducing the amount of aircraft they can safely run through their airspace. Even though there are mathematical formulas for the size of holding patterns, the truth is, we don't know exactly where a holding aircraft will end up. Typically, at higher altitudes, we specify the inbound leg to be between 10-25 miles. However, we don't know how wide the radius of the turns will be. The winds aloft can make a huge difference. Therefore, even though ARTCC standard separation is 5 miles laterally, we generally don't let any aircraft close to the lateral confines of the holding pattern. This severely limits the number of aircraft we can run through our airspace. This is the reason the BADEN sector put us into the hold

Flying during the coronavirus pandemic has proven that changes can happen rapidly. At the time this happened, two areas in Indianapolis ARTCC (ZID) were shut down due to a positive test result for COVID-19. One of their affected sectors is adjacent to the SHD sector. Therefore, we had a lot of aircraft routed around ZID's airspace, flying through ours. The SHD sector was psychotically busy at several times during those days because of it. I know the traffic in the United States overall started going down, but the traffic through SHD sector went way up.

After we finally got all our aircraft into holding patterns, I was relieved from position for the day. Later that afternoon, I looked online and it appeared everybody was delayed less than an hour. We found out that it was only two areas within New York ARTCC that went ATC Zero. Traffic Management Unit (TMU) was able to implement plans that opened up all the major NYC airports. Oceanic traffic, however, was restricted.

Chicago Midway Airport (KMDW) was the first tower to go ATC Zero due to COVID-19. As they do for control towers that close at night, ATC closed via NOTAM three of the four runways (or six of eight runways if you want to be extremely technical). The next day, there were several general aviation aircraft performing touch-and-goes at the uncontrolled field. This put a strain on the incoming IFR traffic (even though Southwest Airlines canceled all its flights). The FAA subsequently published an additional NOTAM prohibiting touch-and-goes.

On April 21st, Washington ARTCC had a positive COVID-19 case. The individual was a contractor whose duties took them throughout the building. Because of this, Washington ARTCC went ATC Zero during the midnight shift so they could perform a deep cleaning throughout the facility. They planned the ATC Zero a few hours in advance, which should have helped with a smooth transition. (I wasn't working.) The facility was opened up early the next morning, resuming normal operations.

Since the onset, there have been a few ATC facilities shut down. Most facilities have found a way to keep operating. The question is: what actions do you take in preparation for the ATC facility you are communicating, or planning to communicate with, when it goes ATC Zero

When Towers are shut down, they typically make an announcement on frequency that they are shutting down, advising pilots in the process what they should do. The ATIS should also state it will be an uncontrolled airfield, while also advising whom to contact for IFR clearances. The good news is that traffic in the pattern is usually aware of their traffic.

As a contingency, during your flight planning, take note of other airfields that could serve as alternates. If you are talking to a tower, then it should convert to uncontrolled, and you should still be able to land. However, it never hurts to know a close alternate airport in case the airport authority decides to close the airport.

If a radar facility becomes ATC Zero, the process is more complex. Typically, another radar facility will take over the affected airspace. However, this could take several minutes to several hours. Once they are set up, however, they will need everybody to change to their frequency and will start by identifying every aircraft. If you are such a sector during this kind of changeover, be extra vigilant of your TCAS or ADSB-In. If you are receiving VFR Flight Following, then you should be able to continue VFR with minimal issues. If you are VFR in Class B airspace, I would exit the Class B as soon as practical.

However, if a facility goes ATC Zero without being able to make a statement on frequency about what is happening and who else to contact, then you should follow IFR communication failure procedures. If you can fly VFR and land, do it.

As most pilots realize, when aircraft are issued an IFR clearance, the clearance itself does not provide traffic separation services. Realistically, it is a route in case of loss of communications. Traffic is separated by controllers on a sector-by-sector basis. Before a controller takes a handoff, they do a traffic scan. They usually fix any issues before taking the new handoff. They may turn or change altitude for the aircraft already on their frequency, or they may call the other controller and have them move their aircraft before taking the handoff.

This is why you may get a turn or change in altitude long after you have been on frequency with a controller. In my opinion, the longer you keep flying on your flight plan without being able to communicate with ATC, the riskier your flight becomes. You may want to think about requiring your passengers to remain seated with their seatbelts on in case of any evasive maneuvers you may have to make.

A good technique is to monitor 121.5. Most Part 121 and 135 pilots are good about monitoring guard. Sadly, I have noticed most general aviation pilots do not monitor guard. Every ATC facility is still required to monitor it at all times (yes, we hear all the stupid comments made on the frequency). This is a good tool to use if you are lost, can't find a frequency or if something abnormal happens where you aren't able to communicate normally. Somebody monitoring guard should be able to get you a frequency to contact the assuming facility. If you are not in range, broadcast on 121.5 in the blind for an aircraft at a higher altitude to relay your message to ATC.

At the time of this writing, the FAA has a link on faa.gov for a list of facilities impacted by COVID-19 and their operational status. You can also visit fly.faa.gov to see the ATC Command Center's Operation Plan. At the end of the day, be prepared for an ATC facility to become ATC Zero. Also, please do not argue about receiving holding instructions. Controllers are generally very good about keeping pilots in the loop when they get new information. Remember, getting you out of the hold and on your way helps the controller, too, by getting you out of their sector, so in the end it's a win/win.