The National Air Traffic Controllers Association, which represents the nation's air traffic controllers, released new details about the equipment outages that prompted ongoing issues at Newark Liberty International Airport in New Jersey.
"On Monday, April 28, air traffic controllers in Area C of the Philadelphia TRACON (PHL), who are responsible for separating and sequencing aircraft in and out of Newark Airport (EWR), temporarily lost radar and communications with the aircraft under their control, unable to see, hear, or talk to them," the union said in a statement.
Archived audio on LiveATC.net from the night of April 28 captured air traffic controllers alerting incoming aircraft that they had lost radar contact. A similar communication outage occurred at EWR on Nov. 6, according to the aviation YouTube channel VASAviation.
Significant delays and cancellations have occurred at Newark every day since April 28, partly because a handful of air traffic controllers went on medical leave following the incident, which forced a slower flow rate at the airport.
"The controllers did not 'walk off the job' as it has been reported by the media. Due to the event, the controllers took absence under the Federal Employees Compensation Act. This program covers all federal employees that are physically injured or experience a traumatic event on the job," the statement from NATCA said. "These professionals ensure the safe movement of aircraft through the National Airspace System as a primary goal."
The Federal Aviation Administration acknowledged the situation in a statement.
"Our antiquated air traffic control system is affecting our workforce," the statement said. "Frequent equipment and telecommunications outages can be stressful for controllers. Some controllers at the Philadelphia TRACON who work Newark arrivals and departures have taken time off to recover from the stress of multiple recent outages. While we cannot quickly replace them due to this highly specialized profession, we continue to train controllers who will eventually be assigned to this busy airspace."
According to data from Cirium, an aviation analytics company, more than 358 departures from Newark have been canceled since April 28, with daily totals ranging from 11 on April 29 to 91 on May 1.
Flight tracking website FlightAware shows that 46 departures were canceled before 9:45 a.m. ET on Tuesday at Newark. Poor weather in the New York metro and runway construction have also impacted traffic at the airport in the last few days.
According to the FAA, inbound traffic to Newark is being delayed at its origin airport by an average of 161 minutes.
New Jersey Governor Phil Murphy wrote a letter to U.S. Transportation Secretary Sean Duffy requesting the Department of Transportation prioritize equipment upgrades at Newark.
"Decades of underinvestment in the maintenance of critical air traffic control infrastructure, delays in upgrading to modern 21st century air traffic control technology, and inadequate air traffic control staffing have resulted in a frail system nationwide," the letter said. "I urge you to prioritize the region, the busiest airspace in the nation."
In a press conference last week, Duffy said that the DOT will announce a plan for technology and infrastructure upgrades to the air traffic control system this week.
(This story was updated to add new information.)
Contributing: Lucas Frau, NorthJersey.com
Zach Wichter is a travel reporter and writes the Cruising Altitude column for USA TODAY. He is based in New York and you can reach him at zwichter@usatoday.com.