Singapore Airlines (SIA) has had five cases of oil leaks on its fleet of Rolls-Royce Trent 900 engines, but they did not lead to the airline having to reduce engine power on flights.
A spokesman from the Star Alliance carrier says the issue behind the leaks was "identified and corrected". "They were minor and we never needed to reduce power during flight," he adds. It is not clear when the leaks occurred or what caused them in the engines, which power the airline's Airbus A380 fleet.
Last month, the Australian Transport Safety Bureau (ATSB) said it was investigating two separate incidents involving decreasing oil quantity on Qantas Airways' Trent 900s.
In both incidents, reducing oil quantity in one of the engines on an A380 forced the flight crew to reduce the powerplant to idle thrust.
The ATSB has said that subsequent inspections into one of the incidents showed that the fitting of the engine's external high pressure / intermediate pressure oil line "had less than the required torque".
The Trent 900's HP/IP bearing module has been linked to last November's uncontained engine failure on a Qantas A380, which has yet to return to service.
In a report on that incident released last December, the ATSB says a manufacturing defect led to cracking within a stub pipe that feeds oil to the HP/IP structure, resulting in oil leakage and an engine failure.
A Rolls-Royce spokeswoman says the engine manufacturer is aware of the latest Qantas incidents.
"We are aware of this event and are working closely with our customers to address it through a system of regular inspections fully supported by Rolls-Royce service engineers. We are co-operating fully with the investigation," she says.