Mysterious disappearances of airplanes belong to age of Amelia Earhart. And yet a 250-ton jumbo jet equipped with space-age systems has been missing for six days. That's because the most critical information about the Boeing 777's flight path and operating systems are locked up in the flight data recorder, or black box, on the missing plane.

As up to a dozen nations expand their search over nearly 27,000 nautical miles, aviation experts question whether it's time to change how planes talk to the ground. Some say that rather than storing flight data onboard, modern aircraft should be transmitting information in a continuous stream during flight.

"In a perfect world, you would do it," says Michael Barr, who teaches aviation accident