US flights: Disruptions could last days after outage

US flights were slowly resuming departures and a ground stop was lifted after the Federal Aviation Administration (FAA) scrambled to fix a system outage overnight that had forced a halt to all US departing flights. But the outage could impact traffic through Friday, said Captain Chris Torres, vice president of the Allied Pilots Association.

"This thing was lifted at 9 am Eastern. That doesn't mean the problem stops at 9 am This is going to cause ripple effects," said Torres, whose members fly for American Airlines.

More than 7,300 flights were delayed and 1,100 cancelled according to the FlightAware website in the first national grounding of flights in about two decades, industry officials said.

The total was still rising and officials said the outage could cause delays through at least until Thursday, if not longer, according to several airlines.

The cause of the problem with a pilot-alerting system was unclear, but US officials said they had so far found no evidence of a cyberattack. US Transportation Secretary Pete Buttigieg told CNN an issue with overnight "irregularities" with safety messages sent to pilots prompted the outage.

He said the ground stop was the "right call" to make sure messages were moving correctly and there is no direct evidence of cyberattack.

The outage occurred at a typically slow time after the holiday travel season, but demand remains strong as travel continues to recover to near pre-pandemic levels.

The FAA said in a tweet that normal air traffic operations were resuming.

One issue airlines are facing is trying to get planes in and out of crowded gates, which is causing further delays. Crew time limit rules may also play a factor.

At an airport in Greenville, South Carolina, Justin Kennedy abandoned a work trip to nearby Charlotte. He said confusion reigned as airline employees weren't aware what the FAA was saying, and many passengers were initially unaware of the delays.

"I sat in a Chick-fil-A dining area that had a good view of the TSA exit," the 30-year-old information technology employee said. "I saw at least four people sprinting to gates because they thought they were going to miss their flight, only to come back to the food court, out of breath."

The FAA had earlier ordered airlines to pause all domestic departures after its pilot alerting system crashed and the agency had to perform a hard reset around 2 am, officials said. Flights already in the air were allowed to continue to their destinations.

Shares of US carriers rebounded after the market opened as flights resumed. The S&P 500 airlines index was up 1% in afternoon trading.