U.S. aviation regulators and airline meteorologists are monitoring the radiation plume drifting northeast from Japan's damaged nuclear reactors to ensure it doesn't threaten commercial jet routes.
The Federal Aviation Administration hasn't decided whether any action is needed beyond tracking the cloud, a spokeswoman, Laura Brown, said today in a telephone interview. American Airlines and Delta Air Lines Inc. said their flights aren't going near any radioactive contamination. Delta operates a daily flight from the Twin Cities to Tokyo.
"There's no problem in avoiding anything that is currently there," said Tim Smith, a spokesman for AMR Corp.'s American in Fort Worth, Texas. "We're already flying in from west of this concern area anyway."
The plume is heading over the Pacific Ocean and contains radioactive barium and cesium emitted from the damaged Fukushima Dai-Ichi power plant, Austria's Meteorological and Geophysics Center said on its website. Particles may start moving northwest if winds shift as expected, according to the data center.
Intensified U.S. efforts to detect radiation on flights arriving from Japan have found no dangerous levels for passengers or cargo, the Customs and Border Protection agency said. The Fukushima plant is about 135 miles (220 kilometers) north of Tokyo and is under a no-fly zone.
Delta today became the first major U.S. carrier to change its Japan service since the March 11 earthquake, tsunami and subsequent radiation leak, suspending service at Tokyo's Haneda airport while maintaining its usual schedule at its Tokyo-Narita hub. The move is an effort to "maximize operational efficiency," Atlanta-based Delta said on its website.
"Delta's meteorology team is continuously monitoring wind patterns and forecasts to ensure Delta flights are following safe flight patterns," a spokeswoman, Betsy Talton, said in an e-mail.
A day earlier, United Continental Holdings Inc. became the first large U.S. airline to say travel had dwindled on Japan routes, saying it has had a "measurable decline" in demand for flights to the country. It signaled that some flying may be cut.
United Continental "will continue to provide the level of service that is warranted by demand and which can be operated safely," said Andrew Ferraro, a spokesman for the Chicago-based company. He declined to comment on whether seating capacity to Japan will be trimmed.
The full schedule of 183 weekly departures to Japan for the Chicago-based company's United and Continental brands remains intact except for a route between Guam and Sendai, where the airport was damaged, Ferraro said in an e-mail.
Deutsche Lufthansa AG was the first major carrier to reroute flights away from Tokyo amid fears of radioactive fallout. Service is being rerouted south to Osaka and Nagoya through the weekend at least, Chief Executive Officer Christoph Franz said in a speech in Frankfurt, its main hub.
British Airways and Air Canada are among carriers pulling crews out of Tokyo, while Cathay Pacific Airways Ltd. reported plummeting travel to the country.
Narita is Japan's main overseas gateway by air, and Haneda is focused on domestic routes while also handling some international flights.