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U-2 Caused Widespread Shutdown of US Flights Out of LAX
Hugh Pickens DOT Com (2995471) writes "Reuters reports that last week's computer glitch at a California air traffic control center that led officials to halt takeoffs at Los Angeles International Airport was caused by a U-2 spy plane still in use by the US military, passing through air space monitored by the Los Angeles Air Route Traffic Control Center that appears to have overloaded ERAM, a computer system at the center. According to NBC News, computers at the center began operations to prevent the U-2 from colliding with other aircraft, even though the U-2 was flying at an altitude of 60,000 feet and other airplanes passing through the region's air space were miles below. FAA technical specialists resolved the specific issue that triggered the problem on Wednesday, and the FAA has put in place mitigation measures as engineers complete development of software changes," said the agency in a statement. "The FAA will fully analyze the event to resolve any underlying issues that contributed to the incident and prevent a reoccurrence." The U.S. Air Force is still flying U-2s, but plans to retire them within the next few years. The U-2 was slated for retirement in 2006 in favor of the unmanned Global Hawk Block 30 system, before the Air Force pulled an about-face two years ago and declared the Global Hawk too expensive and insufficient for the needs of combatant commanders."
It was a NASA owned U-2. They do atmospheric testing. They basically fly a pattern in the sky over and over. The problem with the flight plan was that the U-2 was assigned VFR-on-Top. What that mean is the plane was flying using VFR(Visual) flight rules on top of clouds. This normally occurs below 18000 feet. As such, I think the VFR-on-Top system was only designed for below 18000 feet. As the U-2 was above 60000 feet, the system was processing it for conflicts at every altitude, causing a buffer overflow. They are working on a patch to fix that problem, and in the meantime have implemented a workaround for us. That's what our memo told us at work. Source: I'm an air traffic controller at Denver En-route ARTCC.