Singapore Airlines has checked its Boeing 777-300ER engines to ensure there are no internal cracks after investigations revealed this could have caused a recent fire that forced an aircraft to make an emergency landing at Changi Airport.
The inspections and necessary replacements were completed on July 18, spokesman Nicholas Ionides told The Straits Times.
Flight SQ368 which left Changi for Milan, Italy, on June 27, turned back less than two hours later when the pilots received an engine oil warning. Shortly after the plane landed, its right wing caught fire.
In an interim report, the Transport Ministry's Air Accident Investigation Bureau of Singapore (AAIB), which is investigating the incident, noted that fuel was found in the oil system, which is not normal.
The fuel had entered as a result of a crack in a tube in the engine's main fuel oil heat exchanger - a component that exchanges heat between the engine oil and fuel streams.
Following the incident, SIA accelerated the replacement of fuel oil heat exchangers on the GE90 engines powering its Boeing 777- 300ER aircraft, Mr Ionides said.
SIA has 27 B777-300ERs, all of them fitted with the GE engines.
Further investigations revealed that in December 2014, engine-maker GE Aviation had issued a notice to operators for the component to be removed from the engines, inspected for cracks and repaired if needed.
There was no urgency and the checks could be done when the engine was next due for maintenance, GE said then.
The engine on the SIA aircraft which caught fire had been inspected in March 2014, before the notice was issued. It was not due for another check for some time, The Straits Times understands.
In the wake of the June fire, the AAIB report has recommended that GE Aviation review the urgency rating of the checks "to prevent another fire or other hazardous incident from arising as a result of fuel leakage into the engine oil system".
Aircraft maker Boeing is also advised to consider the need for operational procedures in the event a flight crew encounters a similar fuel leak situation in flight.
As the regulator of both Boeing and GE Aviation, the AAIB has requested that the US Federal Aviation Administration ask both firms to accept the recommendations.
A Boeing spokesman said the firm is providing technical help at the request and under direction of the investigating authorities.
Mr Ionides said SIA will continue to cooperate fully with the authorities. None of the 222 passengers and 19 crew on board was hurt in the June incident.