A Qantas jet bound for San Francisco has returned to Sydney after pilots discovered a "technical issue" about 90 minutes into the journey.
Engineers inspected the aircraft when it arrived back in Sydney on Saturday afternoon, and a Qantas spokesperson said that the problem was "not a safety issue".
"We understand delays can be frustrating for our passengers but we'll always put safety ahead of schedule and our teams are doing everything they can to get passengers back on their way," the spokesperson said.
One passenger on QF73 said the flight had been "ridiculously bumpy" after it took off from Kingsford Smith Airport at 2:10pm.
"The flight got ridiculously bumpy, and the seatbelt sign never got switched off," one passenger told the ABC.
"I'm not sure if it was just turbulence or something else, but eventually they told us that we would be turning back because the autopilot wasn't working."
The plane had to dump fuel over the Pacific Ocean.
The ABC understands engineers replaced a computer part linked to the plane's autopilot system.
The flight was due to take off again on Saturday evening.
