On June 1, 2016, United (UAL) began non-stop San Francisco-Singapore service, then the longest Boeing 787 flight in the world as well as the longest scheduled flight by any U.S. carrier.

The flight seems to have gone well -- well enough that United said it will add another, even longer Boeing (BA) 787-9 flight to Singapore, this time from Los Angeles.

Service will begin Oct. 27, pending government approval.

At 8,700 miles, Los Angeles-Singapore would become the third-longest flight in the world as well as the longest U.S. origination flight and the longest Boeing 787 flight.

"San Francisco-Singapore has done extremely well and there has been a chorus of passengers within the L.A. basin asking for non-stop service to Singapore," said Patrick Quayle, United vice president of international network.

The demand is primarily from business passengers bound for Singapore, Quayle said, adding, "Singapore is a great global economic powerhouse in Southeast Asia."

Passengers who want to fly beyond Singapore can board flights on Singapore Airlines, which like United is a Star Alliance member.

On the San Francisco-Singapore route, about 70% of the traffic originates in the U.S., which is unsurprising since Singapore Airlines also operates between the two cities, utilizing an Airbus A350.

Currently, according to OAG, the world's three-longest flights are Qatar's 9,026-mile Doha-Auckland flight aboard a Boeing 777; Emirates' 8,819-mile Dubai-Auckland flight aboard an Airbus A380 and Qantas' 8,576-mile Sydney-Dallas flight, also aboard an A380.

Fourth is San Francisco-Singapore, which is 8,435 miles. (United has the mileage at 8,446, differing by 11 miles from the OAS measurement).

The Boeing 787-9 has the longest range among Boeing's 787 family. At 8,700 statute miles, Los Angeles-Singapore is at the top end of the range, Quayle said. United will operate the aircraft with 252 seats in two classes. The first 787-9 flew its first commercial flight for ANA in August 2014.

Besides its vast distance, United's planned new flight is noteworthy because it underscores the carrier's commitment to not only operate the country's best trans-Pacific hub at San Francisco International Airport, but also to operate an extremely competitive trans-Pacific hub at Los Angeles International Airport.

On the West Coast, United has San Francisco, Delta  (DAL) has built a trans-Pacific hub at Seattle and American (AAL) has been focused on building its primary trans-Pacific hub at LAX.

At LAX, American is the top carrier in terms of market share, with a 19% share between Jan. 1 and April 30, 2017, according to airport statistics. Delta has a 17% share and United has 14%.

As for international market share, American is first, Delta is second, Air Canada is third and United is fourth.

Nevertheless, over the Pacific, United will serve five destinations: Shanghai, Tokyo Narita, Melbourne, Sydney and Singapore. American serves six: Shanghai, Narita, Tokyo Haneda, Auckland, Sydney and Hong Kong. Delta serves three Pacific markets: Shanghai, Tokyo and Sydney.

Three top executives -- Scott Kirby, Andrew Nocella and Quayle - left American for United early in 2016. While at American, Kirby spoke regularly of the need to build a trans-Pacific presence at LAX, given that United and Delta were focused on building more-exclusive hubs farther north.

Now, United is challenging American on trans-Pacific routes at LAX, where American's ability to gather more passengers - through April 30, it had 4.8 million to United's 3.6 million - is less significant than it might be because LAX is the country's leading origin and destination airport.

"We're the only airline with both San Francisco and LAX as Asia Pacific gateways," Quayle said. "They are the best two airports for Asia Pacific.

"United has a rich history in Los Angeles and we're deeply committed to it," he said. "We have a sizable presence there - a strong local presence and a great flow network - and we are further expanding on it."

Read More Trending Articles:

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.

More from Investing

Amazon's Big Weakness in the Supreme Court Sales Tax Ruling

Amazon's Big Weakness in the Supreme Court Sales Tax Ruling

3 Must Reads on the Market From TheStreet's Top Columnists

3 Must Reads on the Market From TheStreet's Top Columnists

GM Defies Trump's Trade Outlook by Building New Chevy Blazer in Mexico

GM Defies Trump's Trade Outlook by Building New Chevy Blazer in Mexico

Video: Here Is Why Carvana Isn't Worried About Amazon

Video: Here Is Why Carvana Isn't Worried About Amazon

Jim Cramer: Okta Is a Very Expensive Stock

Jim Cramer: Okta Is a Very Expensive Stock