A “hotline” between air traffic controllers at Ronald Reagan Washington National Airport and the Pentagon intended to coordinate aircraft has not worked since March 2022, the Federal Aviation Administration revealed in a congressional hearing Wednesday.

The revelation comes months after the midair collision between a commercial jet and an Army helicopter killed 67 people, raising questions about military aircraft in the congested capital airspace.

Pilots flying into Denver International Airport on Monday couldn’t communicate with air traffic controllers for about six minutes after multiple radio transmitters failed, according to reporting