>> welcome back to our breaking coverage of the search for flight 370. here's what we know, pings detected in the indian ocean could be from the plane's black box. the bigger could is could this be where the plane came to rest. a lot of speculation. we have mary schiavo, aviation analyst. and mr. miles o'brien, cnn aviation expert. mary, i start with you, make a case for why we should all have grace confidence in the pinger locator possibility? >> sure, it sounds like they heard the right megahertz. the reputation, 37.5 megahertz. they were found not once, but price, repeatedly, if it was a