http://avherald.com/h?article=4710c69b
On Mar 12th 2014 Vietnam's Search and Rescue Control Center reported that analysis of satellite images of Vietnams coastal regions, capable of showing objects sized 2.5 meters by 2.5 meters, did not detect any signs of the aircraft. Around noon the Control Center reported, that the search operation continues in full like the days before based on official information from Malaysia that the aircraft has not been tracked in the Strait of Malacca. 9 Vietnamese aircraft and 9 Vietname ships plus 14 foreign aircraft and 22 foreign ships are searching Vietnamese waters.
On Mar 12th 2014 officials of Malaysia's Civil Aviation Authority talking to families of occupants of MH-370 in Beijing reported that the aircraft was just in the process of being handed off to Vietnam, the last radio transmission heard from the aircraft was "Okay, good night". The crew did not report on Vietnam's frequency anymore. About three minutes later Vietnam's control center noticed that the aircraft had disappeared from radar and had not reported on his frequency. There had been no emergency or distress calls on any means of communication, although radio coverage of the area is generally good. Malaysia's CAA officials stressed, that they do not have any indication that the aircraft may have turned back or deviated from the planned route. The aircraft "suddenly disappeared". So far the aircraft has not been found although a total of 1788 ships are participating in the search for the aircraft.
Editorial note on Mar 12th 2014: On Mar 10th Malaysia expanded the search area into the Strait of Malacca assigning substantial forces to that large search area (much larger than the search area in the Gulf of Thailand with a radius of 100nm around the last known secondary radar position east of Malaysia). It remains unclear why this has been done given the Mar 12th denials of reports of Mar 11th that the aircraft may have been tracked by primary radar into the Strait of Malacca explaining that widened search. It also remains unclear why on Mar 12th the search is now moving northwest into the Andaman Sea west of Malaysia, especially when there are/were no indications of the aircraft turning back as Malaysia officials told families in Beijing on Mar 12th.
In the evening of Mar 12th 2014 the commander of Malaysia's Air Force confirmed in a televised news conference, that an unidentified radar target was picked up at FL295 about 200nm northwest of Penang (Malaysia) (editorial note: this translates to just off the coast of Phuket (Thailand) in the Andaman Sea). As the primary radar does not identify which aircraft produced the return (other than secondary radar identifying the aircraft via the aircraft's transponder), it is not clear whether that unidentified target was MH-370. This radar observation however prompted Malaysia's Authorities to expand the search into the Strait of Malacca and Andaman Sea.