Pilots and controllers kept communicating during ground stop of US flights

• The FAA paused departing US flights after an intermittent communications outage on Nov 13, but Sean Duffy said it was not a “complete blackout”.
• Controllers still reached pilots during the disruption, using voice radio and other backup systems, according to the Transportation Secretary.
• Aviation has more backups if radio fails, including text messages, satellite links and tower light signals, which help keep planes safe.

A communications outage on Nov 13 led the US Federal Aviation Administration to pause departing flights nationwide, but pilots were not entirely cut off from federal air traffic controllers.

In a night news conference on Nov 13, Transportation Secretary Sean Duffy said the outage was intermittent, so federal controllers were still able to reach pilots.

“It wasn’t a complete blackout in communication or radar,” he said. “So we were able to keep some of those communications going.”

But even in a complete outage, aviation authorities have multiple backups to maintain contact with pilots.

Pilots and air traffic controllers primarily communicate by voice radio, using primary, backup and emergency frequencies.

Controllers and airline dispatchers can also send text-based messages to pilots. And many commercial planes are equipped with satellite communications, which are especially useful for reaching people on the ground when the planes are flying in remote airspace like over the ocean.

If a control tower loses radio capabilities, it can also communicate with pilots with high-intensity coloured lights, which pilots can acknowledge by rocking their wings or flashing lights in response. NYTIMES

• This article originally appeared in The New York Times.