A Qantas Airbus A380 was forced on Friday to land in Dubai after suffering engine problems en route from Singapore to London.
The incident comes exactly a year after an A380 engine blew up over Singapore but Qantas says they are different planes and unrelated incidents.
Qantas says Flight QF31 suffered a problem with oil pressure in the fourth engine and it was forced to shut it down four hours after taking off.
The plane flew with three engines for about two-and-half hours before landing safely in Dubai.
The airline says it is routine for the A380 to fly with three of its four engines and the 258 passengers on board were advised of the problem. All the passengers and crew are safe.
Qantas spokesperson Olivia Wirth says the airline is working to arrange alternative flights to take the passengers on to London.
Ms Wirth said it was not the same plane as the one that was involved in last year's incident, describing the timing of Friday's incident as a "coincidence".
"These things do happen with all airlines around the world, not just Qantas," she said.
"The captain and the flight crew did absolutely everything possible ... at no stage was there any safety issue."
Qantas grounded its Airbus fleet on 4 November last year for 19 days after a mid-air engine explosion on a flight bound for Singapore.
The cause of that explosion was found to be a faulty pipe in the Rolls Royce engines.