power supply. >> reporter: black boxes contain hundreds of date to points or parameters about the flight's movement, pilot maneuvers, speed, and altitude. all displayed with a serioes of graphs. >> every recorder records the data in binary values, series of ones and zeros. in order for humans to understand that, we need to convert it into engineering units and engineering units mean feet for altitude. air speed is recorded in knots. >> reporter: okay. this right here, that's air speed, correct? >> that's correct. >> reporter: so here as you see getting faster, that represents takeoff. >> yes. >> reporter: it's through graphs like these that we'll learn if someone onboard deliberately nose dived the aircraft if there was a pilot error or a mechanical problem. >> engine or mechanical failure, there would be all kinds of indications. they'd be able to determine which engine turned off first, if it was because of fuel starvation. they would know that versus if it would have been intentionally cut off. >> reporter: this line represents the plane's altitude. if flight mh-370 suddenly