Unimatic is a computer system installed by Tata Infotech for United Airlines in 1997 [1] to track and disburse vital flight data such as scheduling, aircraft weight, and aircraft balance. A massive failure of the system early on 8 August 2025 led to 35% of all United flights being delayed and 7% cancelled throughout the United States, with concomitant effects internationally. Furthermore, the FAA issued an alert cancelling all United flights to O'Hare International Airport; as of 8:45 p.m. CDT, United flights departing from there were delayed an average of two hours. [2] Ground stops were necessitated in Newark, Denver, Houston, and other airline hubs as well as in Chicago. [3] United averred that it was not a cybersecurity incident and that it was a "controllable situation", with passengers being compensated. [4]
