Singapore's Air Accident Investigation Bureau (AAIB) says fuel was found in the oil system of the right engine of the Singapore Airlines Boeing 777-300ER that caught fire upon landing on 27 June.
In the two-page interim statement, the bureau says investigation is still in the preliminary stage but points to three key findings.
It says fuel was found in the oil system of the right engine, which is not a normal condition, and was the result of a crack in a tube in the engine’s main fuel oil heat exchanger (MFOHE).
In addition, the affected engine had last undergone an engine shop visit in March 2014, before GE Aviation issued a service bulletin in December 2014. The engine manufacturer had then called for for carriers to identify certain MFOHEs and remove them for inspection of cracks in the fuel tubes, and to repair if necessary.
The SIA aircraft, registered 9V-SWB, had suffered a fire in it its right General Electric GE90-115BL engine upon landing at Changi airport. Flight SQ368 had to make a turn-back while operating a Singapore-Milan service following an engine oil warning.
The AAIB has since made several interim safety recommendations. GE Aviation was asked to review the need to accelerate the implementation of the recommendations in its December 2014 MFOHE service bulletin to prevent the occurrence of a similar event.
Boeing has also been recommended to review operational procedures for future occurrences of a fuel leak situation in-flight, and for the US Federal Aviation Administration to ensure that such reviews are carried out.
“AAIB’s investigation is on-going and we will be looking into other aspects of this incident that may have safety implications,” it concludes.
Source: Cirium Dashboard