A Qantas flight bound for Sydney had to return to San Francisco on Monday night (PDT) after a fault in its Number Four engine caused a hole to be punched in its surrounding metal shell.

The Boeing 747-400 was about fifteen minutes into its flight when crew and passengers felt “excessive vibrations”, a Qantas spokesperson told e-Travel Blackboard.

“After quick in-flight trouble shooting, the flight crew determined to shut down the engine and get priority clearance to land in San Francisco,” they said.

After the flight landed “with no problems” and passengers disembarked “as normal”, it was soon determined that the engine had indeed failed, at which point Qantas organised for emergency accommodation and transfers to Los Angeles for the flight’s 212 passengers.

“So they’ll all be in Australia tomorrow morning,” the spokesperson said.

"We are dispatching a replacement engine early this afternoon on our QF 73 to San Francisco with a team of Qantas engineers who will begin the investigations into what has happened."