The Federal Aviation Administration is investigating a radio failure at the Denver Air Traffic Control Center, which covers approximately 285,000 square miles of airspace covering parts of Colorado, Arizona, New Mexico, Utah, Kansas, Nebraska, South Dakota, Wyoming and Montana. The outage temporarily affected communications Monday.

According to the FAA, both transmitters that cover a segment of airspace went down around 1:50 p.m., causing a loss of communications to part of the Denver Air Route Traffic Control Center for about 90 seconds. The FAA said the outage affected some flights approaching Denver International Airport.

They said the controllers used another frequency to communicate with pilots, and that all aircraft remained safely separated. Officials said the outage did not impact operations.

National attention was recently brought to the country's aging air traffic control system after a communications glitch at Newark Liberty International Airport in New Jersey. The FAA blamed equipment outages and staffing levels for the incident, stating, "Our antiquated air traffic control system is affecting our workforce."

Transportation Secretary Sean Duffy told the Senate Appropriations subcommittee Thursday that the FAA has resorted to buying replacement parts on eBay and making new parts with 3D printers.

Last week, President Trump announced his administration wants to replace technology at thousands of air traffic control sites.

"After decades of originally — and we're talking about a long time ago — reliable service, air traffic control is long overdue for, not an overhaul really, for a remaking," Trump said. "It's got to be brought up to a modern standard."

Officials said the plans include building six new air traffic coordination centers and replacing technology at over 4,600 air traffic control sites. The administration's plan includes buying 25,000 new radios, installing 4,000 new high-speed network connections, and replacing over 600 radars.

Aviation industry representatives said the plan would cost at least $30 billion to implement.

Editor's note: A previous version of the story misstated where the outage happened. It was at the Denver Air Traffic Control Center, not at Denver International Airport's air traffic control.