'Approach, are you there?' - Audio reveals moment air traffic radar goes dark

Newly-released audio reveals the moment air traffic controllers at one of New York's busiest airports lost communications with planes under their control - leaving one pilot asking, "Approach, are you there?".

The pilot called out five separate times over a span of 30 seconds before the control tower was able to respond, the audio recorded by LiveATC.net reveals.

The tense moments at Newark Liberty International Airport led to multiple employees going on trauma leave, contributing to hundreds of delayed flights.

US Transportation Secretary Sean Duffy said that communications were lost for 30 seconds, and that no planes were in danger.

A few others have estimated that contact was lost for up to 90 seconds.

"That's 90 seconds of a wholly filled-up sky of planes literally flying blind over one of America's busiest airports," said New York Senator Chuck Schumer on Tuesday. "Thank God nothing happened, but we tempt fate if no changes are made."

The audio released on Tuesday by LiveATC.net is between an air traffic control tower in Philadelphia, and pilots flying in the area around one of New York's busiest travel hubs.

"Approach, are you there?" one pilot arriving from New Orleans says, to no response. After five further attempts, over thirty seconds, the tower responds: "I got you loud and clear."

At another point, the control tower tells a United Airlines pilot: "I am gonna move you here because I just got told that the approach lost all the radars."

"Three of their four radar screens went black and they have no frequencies."

The pilot is heard calmly responding: "Alright, we're ready to move."

The incident on 28 April contributed to hundreds of delayed flights that continued into Tuesday.

Secretary Duffy said the outage was "a sign that we have a frail system in place, and it has to be fixed".

The Federal Aviation Administration also acknowledged in a statement that "our antiquated air traffic control system is affecting our work force".

Air traffic control operations at the airport in New Jersey have come under sustained criticism recently.

Last week, United Airlines announced it was cancelling 35 flights per day from its Newark schedule because the airport "cannot handle the number of planes that are scheduled to operate there".