Schmutz is not impressed. He says a system that transmits data in real time only when an emergency is under way could fail to provide investigators with crucial information. 'The most important data when you have a problem isn't necessarily the data you broadcast after you detect that you have a problem,' he says. 'You want to back up 10 minutes and broadcast all of that. If you're in trouble, you're not going to have the time to do that. And you're counting on systems that are in trouble to deliver data.'
Krishna Kavi, an engineering and computer science professor at the University of North Texas, who conducted a study of the EgyptAir flight 990 crash in 1999, says that transmitting continuous real-time data is not as daunting as it may seem.
A plane would not have to rely solely on satellites to transmit its data, he says, because software-defined radios can automatically detect what kind of bandwidth is available at any point during a flight—whether it's VHF, HF, or satellite.
Ten years ago, he determined that each plane needed 2 to 4 kilobytes per second to transmit the data required by the FAA. At the time, there were more than 3000 planes in the sky at any given time over the United States alone.
'Most of us today can get 3 to 6 megabits per second of bandwidth at home. And what we're talking about is maybe one-thousandth of it,' Kavi says. 'The [airlines] are willing to provide Internet on the planes. So if they can provide Internet, they can easily transfer kilobits of data from each plane."
