United Airlines resumed services late Sunday after lifting a ground stop on all domestic flights following yet another IT glitch.
The FAA ground stop lasted more than two hours but did not affect international services.
United gave few details, describing it simply as an ‘IT issue,’ although NBC News reported the problem was related to the Aircraft Communications Addressing and Reporting System (ACARS), citing US officials.
Many disrupted passengers took to social media to vent their frustration.
"We’re working to get flights on their way. We apologize for the inconvenience to our customers," United said in a statement shortly after the ground stop was lifted at 9.00pm ET.
During the ground stop Chicago Department of Aviation said 66 flights were cancelled as a result at United’s Chicago O’Hare hub, and flight tracking website FlightAware reported average delays of about 27 minutes late on Sunday.
Last year saw several major airline IT outages with Delta and Southwest Airlines hit particularly hard.
Both carriers were forced to cancel thousands of flights over multiple days costing tens of millions of dollars.
Just this month, both Air Canada and Porter Airlines reported flight disruption within days of each other due to computer related outages.
