Chief executive of Qantas said on Monday that the carrier has found new problems that will keep its A380 planes out of the sky for a bit longer.

The news follows last week’s episode in which a Rolls Royce engine on one of the Qantas’s Airbus 380s burst and failed shortly after takeoff from Singapore’s Changi Airport. The plane then returned to Singapore for an emergency landing whilst no one was hurt.

The Airbus A380 is the largest and newest commercial aircraft in the sky and saw its debut commercial flight in 2008.

After Qantas engineers scrutinised the engines, the Australian carrier’s chief executive, Alan Joyce, has revealed that further investigations are underway after they had found oil marks where they shouldn’t be.

Mr Joyce added that once the six Qantas A380 aircraft have undergone testing and are deemed to be safe they would return to the sky. He said it would likely take a matter of days instead of weeks, as some had speculated.

Meanwhile, the other two carriers operating the Airbus model- Singapore Airlines and Lufthansa –have given their own A380s the all clear. They have since resumed normal service.

The cause of the engine failure has not yet been identified however Mr Joyce said that engineers believe it was likely a design or material-related issue.