A five-hour computer outage that virtually shut down United Airlines Friday night and early Saturday is a stark reminder of how dependent airlines have become on technology.
Passengers saw their flight information vanish from airport screens, and thousands were stranded as United canceled 36 flights and delayed 100 worldwide.
The airline still had no explanation Saturday afternoon for the outage. But things could have been much worse.
A blizzard in the Northeast wiped out more than 10,000 flights over three days in December, a mid-January storm led airlines to cancel nearly 9,000 flights.
Friday's shutdown occurred late enough in the day that many of the canceled flights were the last planes out for the day, said Henry Harteveldt, an airline analyst with Forrester Research. On a Monday morning, the results could have been catastrophic.