Singapore Airlines (SIAL.SI) plans to replace engines on three of its Airbus A380 planes after finding oil stains on them, almost a week after Australian rival Qantas (QAN.AX) grounded its A380 fleet due to an engine failure.

Qantas’s six A380s have been grounded since Thursday, when a Rolls-Royce (RR.L) engine partly disintegrated mid-flight, forcing the fully laden plane to make an emergency landing.

 

Investigations into that incident have focused on oil leaks inside the Rolls-Royce Trent 900 engines, the same model used to power Singapore Airlines’ A380 fleet.

 

On Monday, Rolls-Royce moved to contain a crisis of confidence in the safety of its engines, saying progress was being made in finding out what caused last week’s blowout on a Qantas A380 flight.

 

Singapore Airlines said its decision on Wednesday to swap out the engines was a precautionary move, on advice from Rolls-Royce, and that the oil stains were unrelated to the Qantas problems.

 

“We apologise to our customers for flight disruptions that may result,” the airline said.

 

Singapore Airlines said the three A380s would be equipped with new engines of the same model, with a minor variation. These aircraft were currently in Sydney, Melbourne and London. A380 flights out of Melbourne and Sydney on Wednesday were cancelled.

 

Qantas, which last week said an engine design flaw could be to blame, has said it is investigating oil leaks that might have caused the engine explosion on a Sydney-bound flight.

 

Qantas is expected to give an update on its A380 fleet by Thursday afternoon. The airline said on Monday it would ground its six planes for at least 72 hours.

 

“We are still continuing with checks,” a Qantas spokesman said on Wednesday.

 

On Tuesday, a Boeing (BA.N) 787 test flight made an emergency landing in Texas with smoke in the cabin, the first incident of its kind, putting additional scrutiny on the already delayed program.