Last Wednesday morning, at the height of the day’s opening travel rush, the computers at the United Airlines operations center suddenly crashed. When a backup computer system inexplicably failed to take up the slack, United was forced to cancel flight departures around the globe.
The outage lasted for roughly two hours, and caused delays of up to 90 minutes for more than 250 flights. Another 24 domestic U.S. flights were canceled altogether.

In a brief statement posted to its Web site, United apologized for the travel disruptions. “We are very sorry for the inconvenience Wednesday morning’s computer outage may have caused you,” the company said. “While United’s operation returns to normal, we continue to encourage you to check the status of your flight before going to the airport.”

Company spokespersons said that United hoped to have all operations back to normal by the end of the day on Wednesday, but conceded that problems and delays might linger until midday on Thursday.

Critical Computer System

The system failure did not pose any operational danger to flights, which remained in constant radio communication with air traffic controllers. However, many United flights landed without any idea of which gate they would be using, and many more flights were simply unable to take off.

The crashed computer system, known as Unimatic, is an essential component of flight operations for United Airlines. Among other things, the system tracks flight time for airplane crews, balances weight and loads on flights, and manages flight plans for pilots. The airline cannot function if the Unimatic system is not operating properly; among other things, Federal law prohibits passenger flights from taking off without a weight-and-balance analysis.

The numerous delays on Wednesday will contribute to United’s already poor on-time performance. According to the Bureau of Transportation Statistics, which began tracking airline on-time departures and arrival in 1995, United flights left on time just 72 percent of the time between January and April of this year.

Little Long-Term Effect

Nonetheless, Morningstar analyst Brian Nelson said he thinks the glitch will have little lasting effect. “This incident is very minor in magnitude,” Nelson said in a phone interview. “I don’t think this will have a long-term effect on the company, and it won’t affect United’s competitive posture.”

Nelson noted that other airlines have suffered much more dramatic scheduling problems, most notably US Airways, following its merger with American West. “After they merged their reservation system,” Nelson said, “they had enormous, long-lasting problems. A one-time event like a computer outage doesn’t affect the intrinsic value of a company like United; but obviously, it could be problematic if it recurs.”