QF9,usually a 17½-hour journey direct from Perth to London,will now stop in Singapore to allow the aircraft to carry a full load of passengers and refuel for a different path.
The return flight,QF10,will still operate as a direct flight on an alternative path due to prevailing winds.
Neither route will be suspended,with the changes expected to last for the foreseeable future.
“We’re temporarily adjusting the flight paths for our flights between Perth and London due to the situation in parts of the Middle East,” a Qantas spokesman said.
“We’ll reach out to customers directly if there’s any change to their booking.”
The airline will continue to monitor the situation,with a range of options available using alternative flight paths.