United Airlines Flight Bound for Hong Kong Makes U-Turn over "Fuel Shortage"

A United Airlines flight bound for Hong Kong was delayed for over a day after making an emergency U-turn back to San Francisco on Sunday, allegedly due to a fuel shortage.

A flight tracking site showed UA flight 869 departed from San Francisco airport at 8:37 p.m. local time on Saturday (11:37 a.m. on Sunday in Hong Kong) but turned back when it reached the Gulf of Alaska. It landed at San Francisco four hours and 20 minutes after its departure.

The flight did not take off again until 3:08 p.m. PDT on Sunday (6:08 a.m. HKT yesterday), according to San Francisco airport's website.

Hong Kong airport's website showed the plane arrived here at 8:36 p.m. yesterday, more than a day after its original scheduled arrival time.

Hundreds of passengers were on board the flight but no one was injured, according to a report by the Australian Broadcasting Corporation.

"we are Sorry for the disruption of your flight experience" Enjoy the 6 hour delay. Thanks @united #unitedairlines pic.twitter.com/ss59Iq2PQ4

- Marcelo Figueroa (@JMarceloFig) October 11, 2015

Based on United Airlines' previous flights for the same route, the plane was believed to be a Boeing aircraft.

The airline did not reply to a request for comments.

It was unclear how many people from Hong Kong and the mainland were on board and how many of the original passengers ended up boarding another flight to Hong Kong or taking the delayed flight.

Emergency crews apparently stood by to inspect the aircraft for a fuel leak, according to the report, citing audio from San Francisco airport's control tower.

Passenger Marcelo Figueroa reportedly said the pilot told passengers there was a fuel problem.

"Apparently the plane was using more fuel than usual and they were not sure if we were going to make it all the way to Hong Kong, so they decided to go back," Figueroa was quoted as saying.

Figueroa also vented his anger on Twitter, posting a picture showing two packs of Oreo biscuits and what appeared to be a travel bag. "Enjoy the six-hour delay. Thanks," he wrote.

"Enjoy the six-hour delay. Thanks," he wrote in the tweet.

Stranded at SFO- Passengers frustrated after Hong Kong flight makes emergency return to SF. ABC7 5&6p. #abc7now pic.twitter.com/p4rKlX78um

- Cbarnard (@CornellBarnard) October 11, 2015

The report also cited a translator as saying a group of Chinese nationals only received a US$20 voucher each for food and were not provided a hotel for the delay.

The translator said they were re-booked on a Sunday evening flight and that if they had stayed beyond Sunday, when their travel visas were due to expire, they would have been present in the U.S. illegally.

Warren Chim Wing-nin of the Hong Kong Institute of Engineers said it was unusual for a plane to run out of fuel only hours into a 14-hour flight.

He said apart from a fuel leak, other possible causes might include problems with readings in the fuel system, if what Figueroa described was accurate.