United Airlines is now flying the longest regularly scheduled route ever flown by a U.S. carrier and one that's a contender for the title of world's longest by flying time.

The Chicago-based airline officially claimed those superlatives late Friday, when it launched non-stop service on the 8,700-mile route connecting Los Angeles and Singapore.

By distance, it’s not the world’s longest – but it’s close. Qatar Airways’ Doha-Auckland route (9,032 miles) and Emirates’ Dubai-Auckland route (8,819 miles) remain the two longest as measured by the most-direct non-stop routing between the cities served.

By scheduled flying time, however, United’s LAX-Singapore is perhaps the world’s longest. Facing typically strong headwinds on the westbound route, United's flight in the direction of Singapore has a whopping scheduled flying time of 17 hours, 55 minutes.

That tops Qatar Airways’ published flying time of 17 hours, 40 minutes for its 9,032-mile flight from Auckland, New Zealand, to Doha, Qatar -- a route that's currently regarded as the world's longest by time.

United’s eastbound return to L.A. is scheduled for 15 hours, 15 minutes.

The Singapore-L.A. route is one of several ultra long-haul routes announced by United during the past two years.

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Prior to Friday’s launch of L.A.-Singapore flights, Qantas' 8,576-mile route between Dallas/Fort Worth and Sydney had been the longest flight to or from the U.S.

Among its domestic rivals, United already flew the longest non-stop route of any U.S. airline: an 8,446-mile flight from San Francisco to Singapore that began in June 2016.

But, with the new L.A.-Singapore route, United is now alone.

“It’s the longest route from the U.S. to anywhere in the world,” Patrick Quayle, United’s vice president – International Planning, told USA TODAY’s Today in the Sky blog about the route when it was announced in June. “It’s definitely prestigious.”

And there’s yet another superlative for United’s new L.A.-Singapore service: It also becomes the world’s longest regularly scheduled route to be flown with a Boeing 787 “Dreamliner.” United already held that title, too, with its existing San Francisco-Singapore route.

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United is flying both of its California-Singapore routes with the 787-9 variant of the Dreamliner.

“The 787-9 allows United Airlines the unique opportunities of opening up long thin routes that we would not have been able to serve non-stop without this specific aircraft,” Quayle said.

United’s new service comes as U.S. airlines have been battling for marketshare at Los Angeles International -- by far the most fragmented of the USA's biggest airports. American and Delta each have been adding new domestic and overseas routes there. Alaska Airlines' merger with Virgin America strengthens its position there by growing its schedule of North American flights.

For United, it adds to the carrier's already formidable presence across the Pacific by giving it two U.S. non-stops to one of Asia's most-important business destinations.

ARCHIVES: United now flying non-stop from San Francisco to Singapore

"What makes United unique is our Asia-Pacific network," Quayle said. "This Singapore flight is just a further example of solidifying that presence from our Los Angeles hub."

However, while United can currently enjoy the “longest U.S. flight bragging rights,” that likely won’t last long.

Singapore Airlines said it intends to restart service from both Los Angeles and Singapore when it begins flying new "ultra long-range" Airbus jets in 2018. Singapore Airlines had previously flown non-stop on those routes, but ended them in 2013 as it retired its older Airbus A340-500 aircraft.

Singapore Airlines also wasted little time in adding its own San Francisco-Singapore route after United did the same.

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