Are black boxes really the key to solving the Flight 370 mystery?

Australia's Prime Minister says he is confident a series of pings is coming from Flight 370's black boxes. If they are in the area where searchers are looking, they could be nearly three miles below the ocean's surface. When and if the black boxes are recovered, there are serious questions about what sort of information will be on them. Randi Kaye takes a look at what investigators were able to learn from the black boxes salvaged in previous air disasters.