This minor incident happened on 27 July 2016 at Singapore Changi International Airport. Singapore Airlines Flight 368 (SQ 368) was a scheduled flight from Singapore to Milan, Italy. All information is taken from TheFlightChannel. The video source is shown below.
On 27 July 2016 0201, at Singapore Changi International Airport, SQ 368 was preparing to lift off to Milan. The aircraft operating SQ 368 was a Boeing 777-312ER registered as 9V-SWB. This aircraft was newly delivered to Singapore Airlines on 5 November 2006 and is 9 years 8 months old. SQ 368 was carrying 222 passengers and 19 crew.
At 0204, SQ 368 was cleared for takeoff. SQ368 lifts off at 0205.
30 minutes later, The aircraft was in the process of climbing to FL330 (33,000 ft). The flight crew noticed that the Oil Quantity Parameter in the EICAS shows 22 units for the left engine, but only 3 units for the right engine. The flight crew also noticed that from the EICAS that the right engine oil pressure was fluctuating between 65 and 70 PSI. However, both the oil pressure and tempreture parameters were within the normal operating range. The pilots tried to look for a solution in the aircraft’s manual. However, they were not able to find an appropriate procedure that addresses the low engine oil quantity situation.
At 0304, the captain of SQ 368 contacts Singapore Airlines Engineering Control Center for assistance. The engineer informed the captain that since the oil pressure was within the normal operating range, there could be a faulty Oil Quantity indication. The engineer advised the captain to continue with the flight, but monitor the right engine oil parameters. In addition, the engineer told the captain that he would also contact the company’s Technical Services Personnel for advice. After being briefed by the engineer on the situation, the Technical Services Personnel believed that it’s a faulty oil quantity indication. However, since SQ 368 just departed, the Technical Services Personnel recommended the flight crew to fly the aircraft back to Singapore.
At 0320, SQ 368 was flying over waypoint ‘VPG’. At this point, the first officer performs a routine fuel quantity check. After comparing the totalizer fuel quantity with the planned fuel remaining quantity, it is determined that the fuel consumption is better that expected. The fuel on board is 600 kilograms more than the expected value.
At 0328, the engineer sends a message via the ACARS to the flight crew informing them about the recommendation by the Technical Services Personnel for the aircraft to return to Singapore. The engineer also informs the crew to contact the Engineering Control Center (ECC). The captain contacts the ECC. The conference call among the captain, the ECC and the Technical Services Personnel is then held. The captain informs the rest that he and the first officer had been monitoring the right engine oil parameters for 50 minutes. Other than the indicated low oil quantity, they could not find any other problems. The call lasts for about 20 minutes. Eventually, they all jointly assess that the flight could continue to Milan. Shortly after the conference call ends, the flight crew feels an unusual vibration in the control column and cockpit floor. The flight crew tried to change the engine power settings. They found that the vibration disappears when the power of the right engine was reduced.
At 0404, the captain informs the engineering centre about the vibrations which the flight crew experienced whenever the right engine was operated at higher power settings. During this call, it was decided that the aircraft would return back to Singapore. However, the engineer states that there was no need to shut down the right engine. A few moments later, a flight attendant informs the flight crew that a particularly strong burnt smell was detected in the forward part of the aircraft. In response, the pilot turned off the right engine bleed system. They then decided to reduce the right engine to idle power and turn the aircraft back to Singapore. However, before reducing the right engine to idle, the pilots adopt the procedure for single engine operation, including a descent to FL170 (17,000 ft). The pilot now insert into the FMC the new flight path that would take them back to Singapore. They also insert the new altitude into the autopilot. New altitude: 17,000 ft. Since the pilots still could not reduce the right engine power to idle, small vibrations were still present during the descent. During the descent, the flight attendant informs the pilots that the burnt smell in the cabin was still present. The pilots switch the right air conditioning to off. Shortly after, the smell in the cabin subsides. The aircraft now reaches 17,000 feet. The flight crew is now allowed to idle the right engine. The vibrations have now disappeared. To bring the aircraft below its maximum landing weight, the flight crew starts dumping fuel.
At 0521, a ‘fuel disagree’ message appears on the EICAS. The flight crew performs the fuel disagree checklist. The aircraft is now 482.8 km (300 mi) from Singapore. The ATC asks SQ 368 if they need any assistance. The flight crew replies that other than the need to fly lower than 17,000 ft, no further assistance is needed.
At 0625, the aircraft is now approaching Singapore. The ATC gives SQ 368 clearance to descend to 7,000 ft.
At 0649, SQ 368 lands on runway 20C. The flight crew deploys both thrust reverser. 20 seconds later, two loud bangs originated from the right engine were heard in the cabin. At the same time, the flight crew hears a soft thud. The control tower informs the flight crew that the right engine is on fire and instructs them to immediately stop the aircraft. The flight crew does not receive any fire warning in the cockpit. The flight crew tells the passengers to stay in the aircraft as there was a risk if they escape immediately.
The fire was brought under control after about two minutes. All occupants, including the flight crew, vacated the aircraft by 0731. Everyone survived the incident.
The air incidents bureau of Singapore, opened an investigation into the occurrence. Investigators found that the right engine’s oil system was contaminated with fuel due to a crack in the engine Main Fuel Oil Heat Exchange (MFOHE). Fuel leaked into various areas of the engine through the core of the engine and the fan duct. When the thrust reverser was deployed during landing, the conditions at the area aft of the turkey feather seal of the core exhaust nozzle resulted in hot surface ignition of the fuel that had leaked from the MFOHE into the various areas of the right engine. As the fire developed, it propagated towards the forward section of the engine and entered the core of the engine through the fan booster inlet. The methods that were used to detect fuel leakage into the engine system by the operator and engine manufacturer were not able to detect the fuel leak that resulted from the cracked tube within the MFOHE when it occurred in SQ 368.
The accident aircraft, 9V-SWB, has since been repaired and returned to service on 12 November 2016. Flights from Singapore to Milan is now known as SQ 356 and SQ 378.
Watch the video below!