The government ruled out a cyberattack as the cause of the technical problems, which forced airlines to cancel about 5 percent of the flights in and out of the country on Tuesday as they tried to catch up.
In 43 instances in recent years, the airline kept passengers stranded on the tarmac for hours in violation of federal rules, the Transportation Department said.
When their flight from Denver to J.F.K. was delayed, six scouts and three adults missed their connection back to Savannah, Ga., and had to make a choice: Wait five days or find their own way home.