Episode 14
The Black Box

Broadcast 6.30pm on 08/05/2003

GEORGE NEGUS: Over the years, passenger flight has become safer and safer, of course, in large part due to the black box flight recorder, invented more than 50 years ago by a Melbourne man, David Warren. Having the black box recorder on board means that air crash investigators are more likely to get an accurate picture of what happens inside a plane just before it crashes. A natural flow-on from that should be improved flight safety standards. As so many great inventions do, it all started from the simplest of ideas.

We visited David Warren to hear his version of the story. And he should know. It's his baby.

DR DAVID WARREN, BLACK BOX FLIGHT RECORDER INVENTOR: The idea for the black box came to me 50-something years ago when the world was at the beginning of the jet age and the first jet airliner had a series of problems, culminating in one major crash in 1953 when a Comet crashed without any explanation, without any witnesses, without any survivors to tell what... A really baffling mystery.

SIMON WATT, REPORTER: So in 1954, David Warren, a young engineer from Melbourne, wrote a groundbreaking report for the Australian Government's Aeronautical Research Laboratories. It was the beginning of the invention of the black box.

DR DAVID WARREN: I had seen at a trade fair, a gadget which fascinated me. It was the world's first miniature recorder to put in your pocket. I put the two ideas together. If a businessman had been using one of these in the plane and we could find it in the wreckage and we played it back, we'd say, "We know what caused this." It's a simple idea, then. Why not have one going in the cockpit or in the... another one, if you like, in the main body of the plane? So that any sounds that were relevant to what was going on would be recorded and you could take them from the wreckage.

The recorder we built for demonstration of the idea consisted of wire being fed backwards and forwards on these spools. And the whole thing was this size, very small, made out of Minifon bits. And the bottom part there, you'll see, I still have the original. And that had all the electronics to mix the voice and the data bits together. So the... the record, when you played it back in the laboratory after the crash, if you like, you could get a complete record written for you automatically of what the instrument's reading, what flight controls were changed, and at the same time, exactly what words were said.

We finished developing this to this stage and, um, found that people weren't interested. We wrote to the Department of Civil Aviation. And the letter we got back said, "Dr Warren's instrument has little immediate direct use in civil aviation." An English firm pounced on the idea and put out a recorder built on our principles, using wire, called the Red Egg. And it was the world's first commercial recorder which could be used for voice or data or both. Now, they were placed in the tail of the plane because...or in the rear end of the plane because when you have a crash, it's the front that gets crumpled and damaged physically. So it's the safest place to put it, most easy to recover it.

SIMON WATT: To survive a crash, the black box is rigorously tested to ensure that it withstands submersion for up to 30 days, heat up to 1,100 degrees, pressure of 5,000 pounds per square inch and a force 3,400 times its own weight.

DR DAVID WARREN: It was called black box because in the records of my meeting in London when it was first demonstrated and they were so keen, one of the people in the discussion afterwards said, "This is a wonderful black box." And a black box was a gadget box. You didn't have to understand it but it did wonderful things. It was a part-time involvement for 15 years before I got the little sign on the bottom, signed by our then superintendent, saying, "I think now our job is done, Dave. We'll... we'll call this a day." Our driving force was air safety so we felt that it's succeeded in that regard. A very satisfying feeling.

GEORGE NEGUS: The black box flight recorder. If you had a hat, you'd have to take it off to the very clever Mr Warren.