All airline traffic within a 250-mile radius of Memphis was shut down and flights heading into the region were rerouted. Flight disruptions were reported in Nashville, St. Louis, Pittsburgh, Miami and other cities.
The FAA is under pressure from Congress and President Bush to reduce flight delays. In the first seven months of 2007, the industry turned in its worst on-time performance since the government began collecting comparable data in 1995.
"The delays are a major concern, but my first thought is about planes being up there without controls and that could jeopardize lives," said Rep. Steve Cohen, D-Tenn., a member of the House aviation subcommittee.
Rep. James Oberstar, D-Minn., chairman of the House Transportation Committee, said his panel plans to look into the project.
"What makes our air-traffic control system so safe is it's heavily reliant on backups, overlaps and redundancies," Oberstar said. "If one system fails, there's another to pick up for it. Something did happen and this backup was not available."