American Airlines made a new request to the U.S. Department of Transportation（DOT） on Monday to launch a direct flight between Los Angeles and Beijing beginning Nov. 5， after obtaining lucrative takeoff and landing slots from Chinas aviation authority.

But a temporary suspension on new routes running from Beijing remains a final obstacle for the airline， said Luo Zhiyu， an aviation expert from web-portal Civil Aviation Resource Net of China.

On July 31， Chinas aviation authority issued a suspension of new flight-route applications until Jan. 31， citing “data that did not meet standards” for the three consecutive months from April to June， without specifying what information was collected.

After beating U.S.-based Delta Air Lines for the route in November， American Airlines had already pushed back its original launch date of Dec. 16 because it was unable to obtain flight slots at Beijing Capital International Airport.

According to a January filing with the DOT， American Airlines requested the U.S. regulator not renew Air Chinas permission to operate a flight route to Houston， in response to the Chinese aviation authoritys failure to make “commercially viable slots at Chinese airports available to American carriers on a reciprocal basis.”

Delta had tried to wrest the lucrative route from American Airlines by submitting requests to the DOT in February and again in July， saying it could obtain the slots through its cooperation with China Eastern Airlines.

For several years， Air China had a monopoly on the lucrative route between Beijing and Los Angeles. In 2016， flights on the route represented 6.69% of all passenger volume between the U.S. and China， with average flight-capacity reaching 82.56%， according to the Civil Aviation Resource Net of China.

In March， American Airlines announced a 1.37 billion yuan （$204 million） investment in China Southern， one of Chinas top three carriers， and it will now hold 2.68% of the Chinese airlines shares.

But in a July earnings call， Stephen Johnson， vice president of corporate affairs at American Airlines， said the deal was contingent on a “slot exchange，”without explaining what this meant.

American Airlines filing with the DOT shows it had obtained a takeoff slot of 6：30 p.m. and a landing slot of 4：20 p.m.， both Beijing time， which are among the most commercially lucrative times for airlines.

As early as 2012， the North China Bureau of the countrys civil-aviation authority recommended foreign carriers work with domestic ones for limited takeoff and landing slots.

Delta worked with China Eastern and Southern Airlines to obtain slots for its flights between Beijing and Detroit as well as Beijing and Seattle.endprint