What travelers need to know about the global tech outage

While commercial air service was slowly recovering Friday after a technology outage caused thousands of flights worldwide to be canceled or delayed, the ripple effect from the disruption left airports crowded with passengers and airlines working to get planes and crews back in position.

“These flights, they run so tightly, so back to back, that even after a root cause is addressed, you can still be feeling those impacts throughout the day,” said Pete Buttigieg, the transportation secretary, in an appearance on CNBC.