A flight recorder, colloquially known as a black box, is an electronic recording device placed in an aircraft for the purpose of facilitating the investigation of aviation accidents and incidents.In the early 1950s none of the recording tapes would survive a burning plane crash, but at a trade fair Dr Warren saw the first of the wire voice recorders. The Miniphon wire recorder was the basis of Dr Warren’s first elemental recorder – now in the DSTO library at Port Melbourne (pictured, top).
He found that capturing clear records of cockpit conversation from microphones in the instrument panel and overhead was anything but easy but over time, he developed usable techniques.Working with instrument colleagues at ARL they found a way of putting flight data as well as voice recording on the wire. This led to the construction of a much improved version in the late 1950s which was very advanced for its time.
Dr Warren showed remarkable tenacity in the black box development; he was a chemist engaged to and under continual pressure to focus on fuels and pass his black box invention over to the instrumentation section.While others could develop the box it was Dr Warren who tried to get it adopted – and against unbelievable resistance. In an official letter from the Air Force rejecting the suggestion of putting boxes on RAAF planes it was stated that Dr Warren’s voice recorder would yield “more expletives than explanations”.
After the fatal crash of a Fokker Friendship approaching Mackay airport in Queensland in 1960, Justice Spicer, chairing the Board of Inquiry, stated that black boxes should be installed in commercial aircraft.But the Australian Department of Civil Aviation purchased a US system instead of Dr Warren’s.The US system proved useless in a subsequent air crash investigation. A commercial opinion of the day said the worldwide market would be as little as six boxes per year as they would only be installed on experimental aircraft during proving flights.The Defence Department declined to patent the device as it saw little commercial justification for the cost of A£2,000.
In 1956 a young Australian engineer, Dr David Warren of the Aeronautical Research Centre in Melbourne, produced a prototype flight recorder called the ARL Flight Memory Unit which improved on earlier models by including voice recordings of the cockpit during the flight. It was the incarnation of an idea he had outlined in a memo two years earlier. Unfortunately the Australian aviation authorities overlooked his invention and it took the British and US to develop and manufacture the device. The flight recorder (or 'black box' as it is commonly known despite being bright orange) is now standard equipment on all commercial aircraft. It has proven to be extremely valuable for investigating the causes of aeroplane crashes, not just through voice recording but also through incidental sounds captured during flight.