black box - flight recorder - flight data recorder

The Black Box Part 1: An incredible story

Martina Roters
1 picture
10 minutes

“Black box finally found!” That’s a common saying after a plane crash. Everyone talks about “the black box.” A mysterious and also quite inappropriate name. First of all, it is not black at all, but signal red and furthermore, there are actually two technical devices which are meant when talking about the black box.

If you have ever flown before, the black box may have saved YOUR life – simply, because you have NOT crashed, because earlier mistakes have been taught and airplanes have been built safer and safer (for example by installing oval windows instead of square ones).

So let’s take a jet and find out what happened back then…

… on the other side of the globe – in Australia – in the first half of the 20th century, where our story will host 3 heroes: One tragic (with a sense of humor to the end) and two not very well-known…

black box - flight recorder - flight data recorder
© Wikimedia Commons Mattes 1

Our tragic hero: A relative who found no rest

In 1935, David Warren, then ten years old, lost his father in one of Australia’s first plane crashes. Reverend Hubert Warren was – without his wife and children – on his way to his new church when the 4-motor propeller plane crashed into Bass Strait. The cause of the accident could never be clarified.

Everybody expected that the bright boy would follow in his father’s footsteps and become a preacher. However, things turned out differently – and this certainly had something to do with the Reverend’s last gift to his son: It was a detector-receiver with which the boy listened to the radio in the boarding school dormitory. With it, his love for science was indelibly inflamed.

David Warren later became a teacher of mathematics and chemistry and eventually a university lecturer. He worked in fuel research and, as an expert from the ARL (Aeronautical Research Laboratories), took part in the investigation of a mysterious series of crashes of the world’s first series jet: the De Havilland Comet. In 1953 and 1954, the aircraft broke apart in a climb – with no survivors.

David Warren - Black Box - Flight recorder
David Warren – Inventor of the black box / © Wikimedia Commons – Australian Government

A gift of heaven from Germany for safety in the sky

According to Warren’s own words, chance played into his hands when he – like the other experts – sat frustrated in the commission of inquiry:

And I had been, just the week before, to an instrument exhibition andhad seen this: This is the world first pocket recorder, if you like, the Minifon, a German unit.”

David Warren

The aforementioned minifon (with coils made of magnetised steel wire) was marketed as a dictation machine for business men. When his colleagues discussed the hypothesis of a terrorist attack, it clicked for him. It was imperative to record what happened in the cockpit!

If you put it up in the cockpit (…) whatever they said there could also be recorded on one of these gadgets, and then taken out of the wreckage and give you an answer.”

David Warren

The prophet did not count for anything in his own country

Unfortunately, his boss at the time forbade him to deal with this idea as it did not fall within his area of expertise. Warren made a new move on the next boss. Tom Keeble was more open to the concept.

Finally, Keeble and Warren presented the idea to the professional world in a Technical Memorandum (TM-142), which was also sent to De Havilland and the British Ministry of Transport, among others. There was no reaction! They repeated the same thing again with a wider circle of recipients, including the Australian Department of Civil Aviation (DCA), American and Canadian authorities, a security foundation. But again, there was no response.

When in 1957 a trade journal reported on the idea of a “photographic flight recorder,” Warren was back on the mat with Keeble. He was afraid that a technology could be implemented that “only took pictures from time to time and thus perhaps missed the critical moment.” Moreover, it would cause psycho-stress for every pilot in the form of a picture record of possible flight errors.

Keeble agreed to build a prototype (partly in Warren’s spare time) and also had him buy a minifon as “office supply”. Infected by the idea, colleagues took Warren on test flights. There, he discovered that directional microphones and filters were necessary to get a comprehensible recording.

Flight recorder precursor

Warren was about to collect more flight data. There was nothing new about this idea, as the brothers Wright and Charles Lindbergh (more here) had allegedly already recorded flight data on board.

Motor pilots Wilbur and Orville Wright
First successful flight of the Wright brothers on 17 December 1903 in North Carolina / © Wikimedia Commons – John T. Daniels

Already, there was the HB-Recorder, named after Francois Hussenot and Paul Beaudoin. It had been developed in 1939 in the French Marignane Flight Test Centre. The device was also known as the Hussenograph. Eight meters of film were exposed in a pitch-black box via mirrors. Depending on altitude and speed, a characteristic image was produced. The disadvantage, however, was that the recording only took place once and then the photographic film had to be replaced.

Warren was working on recording parameters such as altitude, speed, cabin pressure on his reusable magnetic storage devices.

It was 1958 when it happened.

The second hero in this story: The Englishman Hardingham

In the meantime, Laurie Coombes, the head of the ARL, had also been inaugurated. He was visited by a friend from England, Robert Hardingham, from the British aviation registration authority. Immediately, he introduced him to Warren and his heart-felt project. Hardingham instantly recognised the scope of the idea. He arranged a seat for Warren on a Hastings cargo plane to London, where he was to present his idea. Coombes agreed, “Get your passport ready. “

Almost use of the Black Box

Irony of fate: The Hastings, in which Warren sat, lost an engine just behind Tunisia over the Mediterranean Sea. Because of the hellish heat (over 45° at night) nobody wanted to make an emergency landing there. Everybody wanted to try their luck with the remaining three engines until England – despite the hailstorms to be expected there. Warren switched on the recorder, commented loudly on all the events and thought to himself: “If we do crash, I would have proved the bastards wrong.”

Nevertheless, they landed happily and he was able to present his prototype to the interested public. The English media reported enthusiastically; the aviation authority made arrangements for a mandatory deployment. At first, the EMI company acquired a license from the ARL, but six months later returned it for economic reasons.

Even then, there was “America first”

On 2 October 1958, Warren very confidently flew to America to present his flight recorder at Pan Am. The American alternative, a Lockheed recorder, was not very satisfactory for the company. It was very heavy, had to be read out afterwards by microscope and, above all, was not crash-proof.

Later, he summed up his disappointment in the following sentences:

The Americans clearly stated that they were not interested in anything
invented outside the USA.

David Warren

The authorities declined to attend a demonstration at the embassy.

David Warren

Our third hero: Sir John Spicer

There was another tragic plane crash in Australia on 10 June 1960. The nation mourned the crash of a Fokker Friendship with 29 inmates, including 9 school children. The commission of inquiry was chaired by Judge Sir John Spicer. After months of debating hypotheses, he had to inform the public that it was impossible to determine the cause of the crash. It isn’t necessary to know whether Spicer, known as a hardliner, had learned through newspaper reports or directly from Warren that the ARL was working on a device that would have facilitated the crash investigations. In any case, he made a strong recommendation for the completion of such a flight recorder. This was taken up by the then Secretary of Aviation Paltridge.

Warren and the ARL suddenly became the media’s darlings for their “practical contribution in a complex field”. The very next year, the minister declared that the installation of cockpit recorders would be mandatory by January 1963. At that time, Australia was the first nation in the world to make the flight recorder mandatory. The USA followed three years later.

black box - flight recorder - flight data recorder
© Wikimedia Commons Petty Officer 1st Class Spike Call, U.S. Navy

Headwind from the pilots’ unions

Those who vehemently opposed the use of the “spy on board” were the Australian pilots’ union AFAP. No other professional group in the world had to accept such an intrusion into their private sphere.

Warren defended himself against the Big Brother argument, saying that the pilots should be the first to welcome the gain in safety. Simply by avoiding mistakes already made. In addition, his system would permanently overwrite the recording. Therefore, all what was spoken in the sky would no longer be heard when the machine had taken up its final parking position. After decades of struggle, the pilots agreed that the voice recorders could be used after the death of the crew to find the cause of the crash. But still, fought to ensure that they would never be used to prosecute crew members.

Even with a transmitter!

When a plane crashes, the rescue teams search for the signal that the black box sends out. Warren already contacted the Canadian Research Council (NRC) in 1958, which was working on the development of such a transmitter, and changed the arrangement of the coils. Unluckily, the NRC was already working with DSI, a Canadian company that had also developed a system. Nevertheless, Warren received a transmitter copy from the Canadians as a gift and the ARL system could be seen at the 1963 World Exposition. In 1964, it even passed a practical test.

All he had left was his idea

Although Warren’s ARL system unlike other systems

shorter, smaller, lighter and cheaper than other devices, the major Australian airlines Ansett-ANA and TAA agreed in 1961 to jointly buy 70 units of flight recorders and cockpit voice recorders – from:

UDC (United Data Corporation), an American company.

What happened!?

Many blame the Australian Department of Aviation. It is quite possible that there had been animosities since Warren had publicly criticised their inaction in interviews. One of his statements about the ministry had been written down in a way that was proven to be twisted.

In any case, the ministry’s specifications were such that they could be met by magnetic tapes. Unfortunately not by Warren’s wire coil without any modifications. Airline representatives would have liked to wait and see whether the ARL construction, which in their view was advantageous, could meet the specifications by the statutory mandatory date. In a meeting with those, the ministerial director, however, said that he did not expect commercialisation to take place in time and that, in view of the urgent situation, he could not further postpone the deadline for mandatory flight recorders.

New opportunity?

In 1963, the English company Davall & Sons became interested in the licence returned by EMI.

Warren and Cocks, another ARL employee, spent six months at Davall to get the project off the ground. When almost all the negotiations were finished, the procurement people got involved and said they had a say in the commercialization. The fact that they only wanted to give Davall & Sons a license for England was a bad omen. But it was the fact that Davall had been taken out of a contract with the airline BEA by a Plessey recorder, because BEA expected their computer decoders to have more future potential, that killed the project.

Davall & Sons followed the same policy and built the Plessey-Davall recorder instead of the Davall-ARL. It was also called Red Egg because of its appearance. It was later installed in series in many aircraft of the world.

Late recognition and a dash of humour at the end

When he was once asked if he had felt that he had been treated unfairly, Warren replied:

“Yes, the government got the benefit of what I did. But after all, they didn’t prosecute me for the hundreds of ideas that didn’t work.”

David Warrn

In 2002, Australia awarded him a medal for “service to the aviation industry, particularly through the early
conceptual work and prototype development of the black box flight data

Airbus named one of its A380s after him “David Warren” in 2008.

This was two years before his death on 19 July 2010.

His children paid their last respects to his humour by having the following sign put on his coffin:

PS: In part II we will look into the question why the Black Box is called Black Box and what today’s Black Boxes are made of…

Cover picture © Wikimedia Commons Clindberg

by Martina Roters

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