Federal aviation officials say the air traffic control system around Los Angeles shut down last week because data from the flight plan of a U-2 spy plane confused software that runs the system.
A backup system helped safely guide flights already in the air, but hundreds of planes scheduled to fly to Southern California were grounded.
The FAA said in a statement Monday afternoon that software at an air traffic control facility north of Los Angeles "experienced problems while processing a flight plan filed for a U-2."
The spy plane flies at around 60,000 feet under "visual flight rules." According to the FAA, a computer perceived a conflict between the altitude and the use of visual flight rules and began trying to route the plane to 10,000 feet, overwhelming the software.
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