The Department of Transportation’s inspector general has opened an audit into the relocation of the Federal Aviation Administration’s air traffic control facility responsible for flights approaching or departing Newark Liberty International Airport.

Transportation Secretary Sean Duffy requested the audit to see if the move had a role in communications and radar outages at the Newark airport this spring.

Staff are burnt out — and very concerned about safety and feel very strongly that those moved to Philadelphia should come back to this facility,” Gillen said.

Federal audit ordered to review FAA's controversial transfer of air traffic controllers from New York to Philadelphia.

Shortly before the collision, air traffic controllers at Reagan National Airport requested to move the military helicopter route to decongest the area where commercial planes were landing. The request was denied.

The National Transportation Safety Board also released a trove of documents related to the fatal midair collision in January between an Army helicopter and a regional jet at Reagan Airport.