A United Airlines flight from Los Angeles to Sydney, Australia, was forced to make an emergency landing at Sydney Airport on Thursday after the pilot issued a “fuel mayday.”
United Flight 839 was arriving in Sydney with “a mechanical issue” when the pilot issued the mayday call, giving the airplane landing priority over other approaching aircraft.
According to the Associated Press, the United airplane landed safely and taxied to the gate, where its 230 passengers and crew disembarked normally.
Australian Civil Aviation Safety Authority spokesman Peter Gibson said the United airplane was given priority to land, but it had not been in danger despite the mayday call warning of low fuel.
“There’s an international standard that requires that once you get down to your fuel reserve in a flight that you have to declare what is called a ‘fuel mayday,'” Mr. Gibson told the Associated Press.
He further explained that the fuel mayday doesn’t necessarily mean the aircraft is out of fuel. On the contrary, it actually has enough fuel left but has depleted its main fuel supply and is running on fuel reserves.
“It’s a precaution to say: I’m down to my reserve and I need to come in as quickly as can be arranged.” Air traffic controllers then rearrange landing priorities if necessary to accommodate the low-fuel airplane.
Nevertheless, authorities on the ground treat the fuel mayday as a full-fledged air emergency. Police activated a full emergency response and some major roads surrounding Sydney Airport were closed as a precaution.
Mr. Gibson said the United plane encountered stronger headwinds than were forecast for the trans-Pacific flight, making the aircraft burn more fuel than had been planned, according to the AP. The flight typically takes about 14 and a half hours, according to data posted on FlightAware.