FedEx Express, Northwest Airlines and Polar Air Cargo each received clearance from the U.S. Department of Transportation to operate four more freighter flights weekly between China and the United States, starting next spring.

DOT said 15 more all-cargo flight frequencies for U.S.-China routes become available on March 27, 2007, but until 2008 the bilateral accord between the countries limits such allocations to the U.S. carriers that already operate in those lanes.

Currently, FedEx is approved to operate 26 U.S.-China flights weekly, UPS 21, and Northwest and Polar 12 each. All but UPS sought new frequencies.

And because the three airlines that sought new flights asked for four each, or a total of 12, "we are able to grant the applicants all of the frequencies for which they have applied," DOT said.

FedEx has the world's largest freighter fleet and has been rapidly building its China operations. Northwest is the only U.S. passenger airline with freighters - a fleet of 14 747-200s that it plans to update over the next few years.

Polar is the scheduled freight airline of Atlas Air Worldwide Holdings, which also owns Atlas Air's lease and charter cargo airline. Polar recently grounded its older-model 747-200s and is selling most of them, to operate with more efficient 747-400s. Atlas Holdings plans to soon order new-era freighters to rebuild its fleets, reportedly to be 12 747-8s - a model still in development.

Holdings President and CEO William Flynn said Polar already operates 12 frequencies between China's big commercial center of Shanghai and the United States, and with the four additional flights and one of the existing frequencies it will start service from China's capital of Beijing.

The DOT approval notice said that as usual with such flight awards the carriers must inaugurate service within 10 days of the allowed startup date -- by April 4 -- or seek a waiver. Otherwise, the rights revert to DOT.

John D. Boyd