Unlocking the black box: How aviation experts find clues in crashes

Investigators are hard at work trying to piece together the final moments of Russian Airbus Flight A321. U.S. President Barack Obama says there's a "possibility" it was a bomb. British Prime Minister David Cameron says it was "more likely than not a terrorist bomb." And a lot is now resting on what's revealed by the plane's two black boxes.

The plane, which crashed last Saturday killing all 224 people on board, broke up mid-air over Egypt's Sinai Peninsula en route to St. Petersburg. With the uncertainty of the plane's fate, Britain suspended flights earlier this week to the Sharm el-Sheikh airport. And on Friday, Russia's president Vladimir Putin suspended all Russian flights to Egypt. 

Mike Poole knows first-hand the pressure to come up with answers. He is often among the first people to hear a black box recording after a plane crash. He's a pilot, engineer, and from 1983 to 2002 he was an investigator with the Transportation Safety Board of Canada. One of the most high-profile case he worked on was the investigation into the 1998 Swissair crash off of Peggys Cove.

The first listen is always an adrenaline episode for sure.- Mike Poole, aviation safety expert

This interview has been edited for length and clarity.

Brent Bambury: You built the lab that Egyptian investigators are using to examine the black box of Russian Airbus Flight 321. From your experience, what kind of shape is a black box in by the time investigators get their hands on it?

Mike Poole: Well, actually they can be anywhere from pristine - no damage at all - to severely damaged. In the older days, when we had magnetic tape recordings fire was a big problem and melting the tape. Solid state memory chips used today will withstand a much greater fire temperature and we also improved the impact test significantly. 

BB: You were involved in investigating the Swissair crash off of Peggys Cove in 1998 and when that black box  was recovered from the ocean you had trouble even opening it. Why was that?

MP: Well, when we were opening the flight data recorder the underwater locator beacon - which is the pinger that transmits for thirty days to locate the box underwater - that beacon is bolted directly to the internal crash memory. My U.S. colleague was pacing back and forth, so I said "What's the matter? And he said, "Oh we've had it out of the water for fifteen minutes now, we're having trouble getting the beacon off." Because once you remove it things start to oxidize or rust very quickly.

So he took the flight recorder, put it in a vice and took a sledgehammer - if you can picture a golfer - he basically lined up the pinger, or the underwater locator beacon, and he just batted it off with a sledgehammer. It took one second. And he said, "Okay, go ahead and open it." And everybody had a chuckle. It was very innovative.

BB: It's a very low-tech way of opening a very high-tech device. So what was involved in preparing the audio of the cockpit for listening?

MP: So for the cockpit voice recorder, I remember it well to this day. It was probably around three in the morning when we first listened to it. We spent many hours cleaning the tape. It was just like a quarter inch Mylar tape you would have had a cassette player for. It's been submerged in the ocean, so it's wet. And it's got residue and salt deposits. But then once you get the recording we have many high-tech analytical capabilities, such as, noise reduction filtering.

A big one is slowing down the speech because you're talking very fast as a pilot often. And then on Swissair, imagine a cockpit area microphone, it's picking up broad information. And you also have a boom microphone, but the pilots don't wear the boom microphone at altitude. So what we do is we have the air traffic control recording from the ground, which has the aircraft-to-aircraft communications. And we can effectively cancel one from the other. 

However, if you've ever had to do a transcript, it's very cryptic. And a picture would be worth its weight in gold. And I hope someday we get them because with Swissair 111 there were many many conversations and we're going "What are they referring?" because I don't know what checklist you have in your hand. There's lots of nonverbal communications hand signals. How much smoke is in the cockpit? So you can imagine somebody watching a movie, but they can only get the descriptive video. If they can't see the picture, it's a lot harder to understand what's going on.

BB: So you're describing a number of technical problems and issues that create a puzzle that you have to put together in order to get a picture of what happened in those moments of cataclysm. But there's also this reality that you're listening to the last moments of people's lives. And you mentioned the air traffic control tapes, we have a short excerpt from the air traffic control tapes of the Swissair crash. And I just want to play this for you:

Clip: "We are declaring emergency now.... Roger... We have to land immediate... And we are declaring emergency now... Copy that..."

BB: So those are the voices of the commanders in the cockpit and the air traffic controllers on the ground, of the Swissair flight on which 229 people died, everyone on board that flight. So what is it like for you emotionally to be hearing the voices of these people at this crisis moment in their lives?

MP: There's three scenarios that you're involved in as an investigator. One is that the crew survives and that's always a happy investigation because they're around. The second is that the crew didn't know what hit them. We have many cases where they have no idea they're flying into a mountain, for example. There's no emotions. It just abruptly ends right. And then of course, there's the ones where the emotion builds as the catastrophe builds and it becomes less and less likely that it's going to be survivable. And there's no question that's difficult.

But first of all, we don't personally know the crew. So that helps. And our mission really is to understand what happened and and mitigate this problem in the future. And that desire kind of trumps the emotional aspect. And secondly, in the end moments of many recordings it's not good and we'll play that once. We won't play it again because it has no value to the investigation. The problem we're trying to understand has usually happened long before the emotional aspect. But you tend to try to block that out with the mission of advancing safety. 

BB: Some investigators have talked about feeling of a sense of shock or that they've blanked out when they listened to these recordings. Have you ever experienced anything like that?

MP: What I have experienced is when we we do bring in stakeholders that can help us to analyze the recording to understand what happened. In another investigation with Thai Airways one of those individuals knew the flight crew personally and also was responsible for the training. And so you had some feelings of guilt perhaps and "I know these people" and it was very difficult.

BB: We heard the voice of the captain of that craft in those in those recordings. And you have listened to that voice. Do the voices stay with you? Did you recognize that voice when you heard it just now?

MP: I recognized that voice immediately because I have listened to that recording probably for three weeks straight., twelve hours a day when we did the transcript. 

BB: What have you learned about the professionalism of the flight crew, in the face of extreme stress and catastrophe?
    
MP: My father was a fighter pilot and I can tell you that my experience with the pilots is that they're always amazing at focusing on the problem at hand, regardless of how difficult the situation is or becomes. They're very well-trained and well-disciplined. They don't lose it, they just keep going and going and going, so that's been impressive. And it continues to be impressive. 

BB: Mike, I'm talking to you right now on Thursday morning and there are contradictory statements about the Russian Airbus Flight 321 that went down in the Sinai. The U.K. government is saying it was probably a bomb that brought it down and Egyptian officials are saying that that's not true. Your job is to collect evidence, what do you make of the fact that there are conflicting statements about this disaster at this time? 

MP: Well, it's unfortunate that the media doesn't - I don't want to pick on the media too much... but the process is quite simple and it's very effective.The Egyptians are in charge of the investigation. There is a team of international experts in Cairo participating on that investigation. If any official, in any country has an opinion, they should tell it to the team. Not CNN, not the news. Tell it to the team or be part of the team. And when that team is convinced they have something validated and worthwhile saying to the media, they will and it will be through the Egyptian authorities. The problem of people reporting on essentially hearsay, and then it becoming almost a fact, it doesn't help the investigations.

BB: Investigations into plane crashes can take years. And the black box is really one piece of the puzzle. Sometimes it's a major piece, but sometimes there's a lot of other evidence as well. Are there crashes that you've investigated where you still have questions that you'd like to have answered?

MP: The flight recorders in most cases these days are around ninety-eight percent of the investigation. Especially if they're operational, they'll tell you in a heartbeat. If it's something that's not operational it points you in the direction, but then you're going to the other physical evidence. It's more the process that takes a long time, the investigating part is not quite as long.

BB: So in the case of Airbus Flight 321, will we get a definitive answer?

MP: Well, I mean assuming that they get the information off those recorders I think that's going to be extremely telling. So once they validate I've no reason to believe they won't inform the world and they will probably be the very informative.
    
BB: Mike Poole, thank you very much.

MP: Okay, good luck Brent.