A Royal navy ship has arrived in the southern Indian Ocean to verify signals Chinese officials believe could lead to missing flight MH370. The three 'fleeting sounds' have been picked up in the multi-national search currently being conducted 1,000 miles off Australia's west coast. At least one of those 'pings' is believed to have a similar frequency to that given off by a black box. HMS Echo, one of Britain's most sophisticated hydrographic vessels, is racing against time to determine whether the sounds were signals from the plane's black box as the batteries powering the device are expected to run...