When a number of the world’s first jetpowered airliners, the famous De Havilland DH-106 Comet, began inexplicably falling out of the sky in 1953, it looked like the age of commercial jet travel would stall before it even took off. Engineers and scientists pondered on what lay behind the crashes, but there were few clues and no witnesses or survivors.
In Australia, Dr David Warren, a chemist focusing on aircraft fuel, was asked to look into the mystery. Based at the Aeronautical Research Laboratories in Melbourne, Warren’s role was to consider whether fuel explosion could be responsible. However, his interest in plane crashes extended beyond chemistry, for he had lost his father in an unexplained plane crash when he was only nine.
During discussions, it became clear to Warren that they needed more evidence. He wondered if the flight crew could have known what was wrong, and whether it could have been revealed in their conversations prior to the crash. If their voices could have been recorded with a miniature recorder and protected to survive the crash, it might have yielded vital clues. Warren developed his idea into a report, which was distributed to aircraft authorities. Little interest was shown, so in 1958, he constructed a prototype.
Known as the ARL Flight Memory Unit, it was capable of recording four hours of cockpit conversation and instrument readings. Fully automatic, it was designed to operate the whole time the plane was in flight. Eight channels of flight data recorded airspeed, altitude, engine speed and temperature, every two seconds. To protect it from physical impact, the device was contained in a titanium box.
The recorder was offered to potential users, but the Australian air industry was less than impressed. The Department of Civil Aviation even stated: ‘Dr Warren’s invention has no immediate significance in Civil Aviation.’ The Royal Australian Air Force said: ‘We do not need your device…opinion is it would produce more expletives than explanations.’ The Pilot’s Association was indignant; they felt recording their conversations would be like ‘a spy flying alongside’.
In the UK, Warren’s invention was taken more seriously by the Air Registration Board, who decided that the fitting of recorders would become mandatory. The name ‘black box’ was coined by a journalist at a media briefing and has stuck, even though black boxes are actually bright orange. Warren and a team of four developed a pre-production prototype, with more sophisticated electronics and data storage for 24 readings per second. Warren’s prototype led to the first commercially manufactured flight-recorder, the ‘Red Egg’, which was produced by the British firm S Davall & Son.
In 1961, Australia suffered another major unexplained aircraft accident. The presiding judge at the accident’s inquiry ordered black boxes be compulsory fittings in civil aircraft. But recognition of the inventor’s contribution to air safety took a long time in coming. It wasn’t until 2002 that Dr David Warren’s contribution was officially acknowledged in the 2002 Australia Day Honors List, for ‘service to the aviation industry, particularly through the early conceptual work and prototype development of the black box flight data recorder’.