The FAA plans to reduce the operating hours of air traffic control personnel at about 100 ATC towers and terminal radar approach control facilities in late April to limit employees’ exposure to the coronavirus as the pandemic slows flight activity in the national airspace system.

Editor's note: This article was updated April 27 with links to the FAA's list of ATC facilities with reduced hours.

Editor's note: This article was updated April 27 with links to the FAA's list of ATC facilities with reduced hours.

No end date was given for the downsizing that will affect ATC facilities in Class C and D airspace where traffic volume has declined as much as 96 percent.

The modifications will be reviewed regularly for an eventual return to normal operations, said Rune Duke, AOPA senior director of airspace, air traffic, and aviation security. The FAA will conduct a regular analysis of traffic levels to determine how to appropriately staff the facilities.

“These facilities have seen a significant reduction in flights, especially during the evening and nighttime hours, since the pandemic began,” the FAA said in an April 22 coronavirus update. “Adjusting the operating hours will further protect our employees and reduce the possibility of temporary tower closures from COVID-19 exposures by ensuring enough controllers are available to staff the facilities during peak hours. It also will enable us to allocate difficult-to-source supplies where they are most needed.”

AOPA and other aviation associations have been providing the FAA with feedback on issues to be addressed to ensure safety and procedural clarity, and to maintain efficiency when the roughly 100 affected facilities reduce their operating hours.

“We are taking a close look at the FAA’s strategy and their initial list of locations,” said Duke. “The FAA and air traffic controllers have done an outstanding job to keep the system running during this extraordinary time. Their collaboration with aviation stakeholders has been key to ensuring the safety and efficiency of the system.”

Some of the issues AOPA has raised are without systemwide precedent: In the case of airports that are usually served continually by ATC, AOPA and other aviation groups are developing general recommendations on how such responsibilities as the posting and consistent dissemination of notams, and the monitoring of navaids, should be handled when the tower is closed.

Pilots may need to brush up on related procedures such as preflight planning: For example, if a navaid is unmonitored, an instrument approach such as an instrument landing system (ILS) may not be available, reducing an airport’s availability as an alternate during flight planning.

Also, the class of airspace that takes effect when a normally 24/7 Class C or Class D airport tower closes must be determined and made known to flight crews, he said. By contrast, the after-hours airspace classes in use at airports that regularly operate with part-time ATC service are published in flight publications and on navigation charts, making the information easily accessible to pilots. Clear guidance on such basic questions will help reduce the overall risk, Duke said.

The FAA is working to publish guidance materials and frequently asked questions about the operating changes. A list of affected ATC facilities is available, he said.

The AOPA Air Safety Institute recently released a safety notice about ATC zero events that provides additional guidance on what pilots can do during preflight to ensure they have all of the pertinent information.

“Notams will remain the best source of information for ATC and airport status, and we encourage pilots to check this source regularly,” said Duke.