Transcript for Analysis of black boxes from deadly Ethiopian flight delayed for another day

We're going to turn to new reporting after the grounding of Boeing's new 737 max jets. The U.S. Was the last to order them grounded. A line of those planes right there, you can see at the airport in Phoenix today. And tonight, the black boxes from the ethiopian plane are being analyzed in France. And right here, you're about to see some of the evidence side-by-side tonight. What alarmed authorities right here at home, leading to that decision to ground the jets. ABC's David Kerley back on the story tonight. Reporter: The data in this mangled flight recorder could solve the mystery. But extracting that data from the boxes, which ethiopian officials carried into the French safety board in Paris, will not start for another day. That left 737 max aircraft towed in Tulsa to be parked, the jetliner grounded worldwide. Hundreds of flights are being cancelled. The concern -- similarities between the ethiopian crash and one less than five months ago, a both jets after takeoff, moving up and down erratically. In the first crash, an automated safety system to prevent a stall, did play a role. This is a graph of the up-and-down movement of the lion air jet. Experts zeroing in on a 20-second dip. When compared to the ethiopian graph, another 20-second dip. That similarity, triggering the FAA to ground the fleet. The graphs were similar between lion air and Ethiopia. Why? We don't know exactly. That needs to be sorted out. And the only way to do that is with data from the flight data recorder. Reporter: Experts say the data from those boxes can be read out in a matter of hours. And it should tell us were the accidents related? Is there a possibility it was pilot error or some kind of mechanical problem that we've not heard about? David Kerley tonight. Thank you.

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