Boeing and General Electric are investigating the cause of two in-flight shutdowns of a GE90-115B on a 777-300ER just before its delivery to Air France.

The aircraft, delivered to the airline without incident on 30 May, had been performing standard Boeing pre-delivery flights when the crew twice received low oil-pressure warnings and performed two precautionary in-flight shutdowns. After landing, it was discovered that in both events the oil scavenge pipe to the 'A' sump in the engine had collapsed, causing the pressure to drop.

GE says the incident is "unique to this engine" and tests are being performed on the tube at its Cincinnati plant. "That particular engine is being closely monitored, but subsequent runs on it after the pipe was replaced have been uneventful," says GE, which changed the engine before delivery.

Boeing, which plans to deliver 16 777-300ERs to Air France by the end of 2006, says the failure appears to be a "quality issue". The aircraft, line number 480, is the third delivered to Air France.

GE says destructive tests continue, but there has been "no evidence" to date of a quality problem with the tubes. It says engine certification, production ground test, flight test experience and analytical predictions do not currently foresee the scavenge pressures needed to cause the tube to collapse.

Source: Flight International