The document summarizes information about flight data recorders and cockpit voice recorders, commonly known as the "black box". It discusses the history of black boxes, how they work, and what they record. Flight data recorders track parameters like time, pressure, airspeed and engine functions. Cockpit voice recorders have microphones to record sound in the cockpit, including conversations between pilots and air traffic control. Black boxes are designed to survive crashes and help investigators determine the causes of accidents.