David Warren invented the black-box voice and data recorder while working for the Australian government. His reward? A paid trip to England accompanying his prototype for testing.
David Warren invented the black-box voice and data recorder while working for the Australian government. His reward? A paid trip to England accompanying his prototype for testing.
 
Black boxes have a shell of stainless steel about 0.25-in. thick, a 1-in.-thick layer of thermal insulation against fire and heat, and a thin layer of aluminum around the memory-board stack. They are usually mounted in the aft end of the plane, letting the entire front portion of the plane serve as a crush zone and increasing the likelihood the black box will survive.
Black boxes have a shell of stainless steel about 0.25-in. thick, a 1-in.-thick layer of thermal insulation against fire and heat, and a thin layer of aluminum around the memory-board stack. They are usually mounted in the aft end of the plane, letting the entire front portion of the plane serve as a crush zone and increasing the likelihood the black box will survive.


Senior Editor

Black box: The final witness

While investigating a rash of Comet jet airliner crashes in the early 1950s, David Warren, a chemist at the Australian Aeronautical Research Lab, quickly realized that airline accidents tend to leave few witnesses from onboard the crashed airplanes. This made it extremely difficult to reconstruct events in the plane just before the crash and, more importantly, prevent reoccurrences.


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Warren's solution was the flight data and cockpit voice recorders, collectively known today as black-box recorders even though they are routinely painted bright red or orange so they are easy to spot amidst wreckage and undergrowth. His first prototype was a wire recorder inside a box stuffed with asbestos. It stored 4 hr of cockpit conversation and a dozen or so flight instrument readings sampled eight times/sec.

Initial reactions were less than encouraging. The Royal Australian Air Force dismissed the idea, saying "such a device would record more expletives than explanations." And the Federation of Air Pilots stated it would be like "a spy flying alongside . . . no plane would take off in Australia with Big Brother listening." Eventually, as air accidents increased, support for the black box grew. By the late 1950s, British authorities mandated it for civil airliners, and after an accident in Queensland, Australian officials followed suit in 1960.

Initially, the devices used 0.005-mm steel wire to record 24 readings/sec that were time and frequency multiplexed using a solid-state sampling switch. Eventually, technology moved to magnetic tape, which could store 100 parameters, and then to memory chips, which let black boxes track more than 700 parameters. Those parameters include time, pressure altitude, fuel flow, control-wheel position, magnetic heading, vertical acceleration, and flap settings. They've proven invaluable in determining the cause of air crashes and preventing future ones.


Safety in the front seat

Early aviators and their open cockpit planes had few safety devices. Some aircraft designers, like the Wright Brothers, specified corduroy seats to increase the friction between the seat and the pilot, hoping to keep the two together. But it was hardly adequate. In 1912, Ensign William Billingsley flying 1,600 ft above Chesapeake Bay in a Wright seaplane ran into severe turbulence. It threw him out of his seat and into the Bay, making him the first Navy pilot to be killed while flying. His passenger, Lt. Tower, managed to catch himself and hold onto a wing strut as the plane crashed into the water. Soon after, as the officer in charge of training flyers, he ordered safety belts for all Navy aircraft.