CNN CNN Newsroom January 3, 2015 17:17:00
Two different boxes, one being a cockpit voice recorder the other being a flight recorder. together they weigh anywhere from 30 to 40 pounds. and they have to be crash proof. black boxes can survive anything. temperatures up to 2,000 degrees fahrenheit for an hour. forces that are 3400 gs. that's 34 times the force of gravity. waterproof and can save data for two years. and it's a lot of data. a-rods the crew's voices. experts can determine if a stall took place, the rprs of the engine and the speed at which the plane was traveling when they're cross-referenceded with ground control informatio...