United States — August 7, 2025
A widespread technical failure brought United Airlines to a standstill on Wednesday evening, as the carrier temporarily grounded all mainline flights across the country. The outage triggered major delays and cancellations, disrupting travel plans for thousands.
The issue began at approximately 5:12 p.m. CDT, when United’s internal flight operations platform—Unimatic—suffered a critical malfunction. The system, which handles vital flight data such as aircraft weight and balance, is essential for safe departures.
United Airlines confirmed that the outage was not the result of a cyberattack, but rather an internal technical fault. The Federal Aviation Administration (FAA) was alerted, prompting a nationwide ground stop for United flights.
🔎 Quick Breakdown
- Flights delayed: More than 1,000 flights were delayed at major hubs including Chicago O’Hare, Denver, Newark, Houston, and San Francisco
- Flights canceled: Dozens of flights were canceled, leaving passengers stranded both in terminals and onboard aircraft
- Recovery: The system was restored within hours, and flight operations resumed gradually
United issued a public apology and assured travelers that a full investigation is underway to identify the root cause and prevent future disruptions. The incident has reignited concerns over the fragility of legacy airline systems and their ability to handle modern operational demands.