It is the most recent in a series of problems plaguing the country’s aviation infrastructure that have sparked widespread concern.

The incident follows recent radar outages at New Jersey’s Newark Airport due to the FAA’s antiquated infrastructure, adding to safety concerns about flying in U.S. airspace.

Air traffic controllers’ radio at Denver International Airport experienced an outage for a minute-and-a-half this week, according to the Federal Aviation Administration (FAA). The federal agency said a part of the Denver Air Route Traffic Control Center suffered a loss of communications for about 90 seconds at around 1:50 p.