success. >> one of the audio streams is readable. >> reporter: the cockpit voice recorder captured audio up to the moment of impact. it will provide critical information like whether the pilots were talking in the minutes leading up to the crash. >> they can hear what switches are being thrown and what buttons are being pushed. >> reporter: investigators say the plane disappeared from radar 53 minutes after takeoff and the final minutes of dissent appeared controlled. >> translator: the curve is compatible with an aircraft controlled by pilots except for the fact that we can't imagine pilots consciously sending and aircraft into a mountain. but it may also be compatible with an aircraft which is controlled by an automatic pilot. >> reporter: the ceo of lufthansa says he is struggling to understand why this plane crashed. >> we cannot understand how an airplane which was in perfect