Carol Cavalcante, an official with Brazil's national airport authority Infraero, confirmed that radar under the command of the Cindacta-4 radar center headquartered in the Amazon city of Manaus went down, but didn't give an indication as to what caused the problem.

"Everything is back to normal now. It was out for about two hours. It's true, some flights were sent back to their point of origin at that time," Cavalcante said.

Marc Henderson, a spokesman for the Miami International airport, said four American Airlines flights heading to Sao Paolo and Rio de Janiero were sent back to Miami. He could not confirm whether it was because of radar problems.

Three of the flights had originated in Miami, and the other began in Dallas-Fort Worth International Airport, he said.

American Airlines, based in Ft. Worth, Texas, did not return phone messages left on its after-hours hotline or with its Miami spokeswoman.

Saturday's radar problems come on the heels of Tuesday's crash at an airport in Sao Paulo, Brazil's largest city. The accident—the worst in Brazil's history—killed 191 people.

A surge in travelers has overwhelmed underfunded air traffic control systems in South America, making flying to the region frightening and time-consuming for passengers and pilots alike.

Last September, a commerical jet with Brazil's Gol Airlines collided with a small executive jet over the Amazon, causing the Gol jet to crash, killing all 154 aboard.

A Brazilian judge indicted four flight controllers and the smaller jet's two American pilots on the equivalent of manslaughter charges, but the defendants point to other problems, from holes in radar coverage to the inability of some Brazilian controllers to clearly speak English, the language of international aviation.


AP