Last week, hundreds of flights were canceled or delayed along the West Coast went ground control computers connected to several major airports went haywire. According to NBC News, the problem arose because a Cold War-era spy plane flying through California airspace wreaked havoc with the system. Unfortunately, the U.S. Air Force doesn't agree with that interpretation of events.
NBC News, citing anonymous sources, reports that the Lockheed U-2 passed through airspace monitored by L.A. Air Route Traffic Control Center in Palmdale, California, on Wednesday afternoon and confused the ERAM computer system that air traffic controllers use to make sure flights don't collide. Per NBC:
The U-2 was flying at 60,000 feet, but the computers were attempting to keep it from colliding with planes that were actually miles beneath it. Though the exact technical causes are not known, the spy plane’s altitude and route apparently overloaded a computer system called ERAM, which generates display data for air-traffic controllers. Back-up computer systems also failed.
The chain of events started with a flight plan that resulted in an improper computer code for the U-2's flight, according to one person, apparently prompting malfunctions that overwhelmed the computer system. The system ultimately went into overload and shut itself down as a precautionary measure.
On Wednesday, Los Angeles International Airport (LAX) diverted ten incoming flights and grounded a number of others as a result of the computer malfunction. LAX spokeswoman Nancy Suey Castles told CNN at the time that "Airlines at LAX are reporting an estimated 10 cancellations and 110 departure delays throughout tonight." John Wayne Airport in Orange County, Bob Hope Airport in Burbank, and Bay Area airports were also affected, as were airports in Las Vegas and Salt Lake City. Officials reported at the time that the confusion was caused by technical glitches.