BEIJING, CHINA - MARCH 09:  (CHINA OUT) 'Haixun 31' (C), the largest patrol vessel in South China Sea, prepares to depart from the port for search and rescue mission for the missing Malaysian Airline flight on March 9, 2014 in Beijing, China. Potential sightings of possible airliner debris and a possible oil slick in the sea off Vietnam have not been officially verified or confirmed as investigative teams continue to search for the whereabouts of missing Malaysia Airlines flight MH370 and its 293 passengers, travelling from Kuala Lumpur to Beijing. The airliner was reported missing on the morning of March 8 after the crew failed to check in as scheduled. Relatives of the missing passengers have been advised to prepare for the worst as authorities focus on two passengers on board travelling with stolen passports.  (Photo by VCG/VCG via Getty Images)