Air-traffic control centers in adjacent regions handled flights that were already in the air when the problem was discovered.
"The airspace was completely cleared by 1:30 (p.m.) Eastern time," FAA spokeswoman Kathleen Bergen said.
High-altitude flights through the region -- which includes parts of Alabama, Mississippi, Arkansas, Missouri, Indiana, Kentucky and Tennessee
-- were discontinued while the equipment was being fixed.
"What we did is put a ground stop in place for any flight that would transition through that airspace. We held them on the ground wherever they were, whether it was Miami, Seattle, Los Angeles, Boston," Bergen said.
The FAA's action had a ripple effect in several airports.
David Magana, a spokesman at Dallas-Fort Worth International Airport, said about 50 flights had been delayed, but were in the process of departing Tuesday afternoon. About 50 other flights had to be canceled.
In Nashville, 12 Northwest Airlines flights were diverted, and 25 to 30 departures had been delayed one to two hours, airport spokeswoman Emily Richard said. Disruptions affecting fewer flights were reported at airports in Los Angeles, St. Louis, Miami, Pittsburgh, Louisville, Ky., Kansas City, Mo., and Tampa, Fla.
No major problems were reported at Atlanta's Hartsfield-Jackson Airport or Chicago's O'Hare and Midway airports, aviation officials said.
[to top of second column]
Memphis, with the headquarters of shipping giant FedEx Corp., is the world's busiest airport for cargo, handling 4.08 million tons of air freight in 2006. The Memphis airport also is a hub for Northwest Airlines.
It was not immediately clear how much the flight disruptions had affected FedEx, company spokesman Jess Bunn said. The busiest part of the company's day is early in the morning.
Operations were back to normal by about 3:30 p.m., said Laura Brown, a spokeswoman for the FAA in Washington.
Brown said the outage affected the center's ability to talk to flights passing through its airspace and to other air traffic control facilities.
Brown had no further details, including which telephone company operates the line that was lost. She would not comment on a statement from the Air Traffic Controllers union that was e-mailed to reporters, explaining that its members had to use personal cell phones to talk to other facilities about specific flights immediately after the Memphis center lost communications.
The Memphis center is one of 20 around the country. It handled almost 3 million flights last year, ranking it ninth among the 20.
"It's a big airspace, and there are lots of airplanes," Bergen said.
[Associated Press; by Woody Baird]
Copyright 2007 The Associated Press. All rights reserved. This
material may not be published, broadcast, rewritten or