David Warren - Inventor of the Black Box Flight Recorder

The device would be fire proof (using steel wire as the recording medium like the "Pocket Recorder") and erase itself so that the last hours of the flight were always recorded.Dr Warren wrote the initial ground breaking report for ARL entitled "A Device for Assisting Investigation into Aircraft Accidents" in 1954.

Despite being published twice (including overseas), the report still failed to generate much interest and with further support form new Superintendent Tom Keeble, it was decided to take a "Show and Tell" approach by creating a prototype. After a series of tests the first "ARL Flight Memory Unit" was then produced.

The device consisted of a single steel wire as the recording medium and provided four hours of recording and automatically switched itself on and off with the aircraft. It was during this period that Dr Warren incorporated the idea of recording instruments on a separate channel - his interest in electronics as a schoolboy was brilliantly applied to turn instrument readings into recordable dots and bleeps.

Using this technique, the original unit was able to record data from 8 instruments every 2 seconds.The response was still less than encouraging with authorities still reluctant to accept the potential benefits of the device.

The project was given fresh impetus after David, who was working on the prototype during a lunchbreak) was given a brief introduction to the Secretary of the UK Air Registration Board, Sir Robert Hardingham in 1958. Hardingham immediately recognised potential of the flight memory device and David was put on a four day flight to England to demonstrate the invention. The flight (almost the only tangible reward Dr Warren has ever received for his invention) was an adventure in itself.

A detour through Africa eventuated in a historic recording of a lion hunt in Nairobi and the first ever "black box" recording on the last leg of the flight - chiefly because Dr Warren was nervous about the fact that one engine was out.

The recorder was well received in England (where the name "Black Box" was coined by a journalist at a briefing) and also in Canada where the idea was seen as a potential addition to beacons being developed there.

Dr Warren continued to lead the project, developing the Flight Memory device to record more instruments with greater accuracy. This led to the first commercially produced flight-recorder - the Red Egg - which was manufactured by British firm of S. Davall & Son and captured a large part of the British and overseas market at that time.

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