MARGARET WARNER: The majority of the passengers on Flight 447 were French and other Europeans and Brazilian, but Air France says two Americans were also on board.
We take a closer look now at what could explain Flight 447′s disappearance. For that, we turn to Ben Berman, a commercial airline pilot and the former chief of major investigations for the National Transportation Safety Board.
Mr. Berman, thank you for coming in.
BEN BERMAN, former National Transportation Safety Board official: You’re very welcome.
MARGARET WARNER: Let’s start — there are many mysteries here, but let’s start with the first one. Why is it so hard to pinpoint exactly where this plane went down and when?
BEN BERMAN: Well, over the domestic United States, all the airliners are in radar contact from ground-based radar facilities. But out over the middle of the ocean, there’s no radar, because it’s got to be sitting on the ground and have its antenna radiating from there.
So there’s tracking of the aircraft by air traffic controllers, but it’s done by voice communications and in some cases by data link, reporting in position every once in a while over certain fixes.
MARGARET WARNER: So there really are periods where a plane is flying and it’s not in touch with anyone?
BEN BERMAN: That’s true, but in all cases an airplane could be in touch. Most airplanes now of that size and nature are equipped with satellite phone communications. And so, in the event of trouble, the pilots could pick up the phone, in a sense, and get in contact with their companies or with air traffic controllers. And in this case, they didn’t do that.
MARGARET WARNER: Well, let's turn to the big mystery, which is what could have happened. What do you think are the plausible possibilities?
BEN BERMAN: Well, there are so many at this point because there's so little information. But we know that the airplane was operating in an area of turbulence around thunderstorms.
And turbulence can bring down an airplane. It's got to be pretty bad, and it's got to have the airplane go into a place where the pilots didn't intend it to go. But if they weren't able to avoid a thunderstorm or went into some severe turbulence that was outside the area that was shown on their own weather radar, they might have gotten into severe turbulence.
MARGARET WARNER: And what then happens in that situation?
BEN BERMAN: Well, airplanes are stressed to take severe turbulence without breaking up. And that makes them quite capable and quite safe.
But if there were to be a loss of control where the airplane were to get its nose down and start picking up air speed combined with turbulence or if there were something similar perturbations, then it's possible that there could be a structural failure or that systems could fail because of the upset.
MARGARET WARNER: Now, do you -- I saw you shaking your head when lightning was mentioned in the tape piece. Do you dismiss that as a possible cause?
BEN BERMAN: It can't be dismissed. It's possible. But lightning hasn't brought down an airliner in many, many, many years, and there have been a lot of advances in lightning protection of airliners.
They have to meet a lot of strict capabilities in terms of dissipating the charge and letting it pass through the aircraft without causing any damage or serious damage. And it just has not been a thing that brought down an airliner. It's possible, but my guess is that something else or some combination of circumstances was more likely to have done this.
MARGARET WARNER: And it's not unusual, I gather, for a plane to be hit by lightning. It's not usual, but it's not unheard of.
BEN BERMAN: Well, that's right. I mean, as an airline pilot, I've been hit by lightning and had no damage or tiny pinholes in the fuselage or an end of the aircraft. But it happens a lot with very little consequence.
Thunderstorms near the equator
MARGARET WARNER: Now, it was flying -- when it hit this period of turbulence, it's been said that it was in something called the Intertropical Convergence Zone. Now, what is that?
BEN BERMAN: The Intertropical Convergence Zone is an area near the equator where air is rising because of the heat and moisture of the water. It rises up to great heights, and it gives rise to some pretty tall thunderstorms that can build in close to each other. If you look at it on a satellite map, it can look like a line of weather, a line of thunderstorms that goes, for instance, almost all the way across the Atlantic Ocean.
MARGARET WARNER: And it's up that high? It's up at 35,000 feet?
BEN BERMAN: Yes, 35,000 feet is not very high for a thunderstorm. These can build quite a bit higher because of the height of the atmosphere in the equator area. And so it can be tall thunderstorms. They can be quite close to each other. And they have to be traversed very carefully.
MARGARET WARNER: Now, have you ever flown through this zone?
BEN BERMAN: I've flown through it a couple of times. I don't go there very often. But it's something that airliners traverse every night back and forth. And it's something that can be dealt with.
MARGARET WARNER: So what is it like?
BEN BERMAN: You would spot the thunderstorms on your airborne weather radar. You can see the outline of the precipitation that's in the thunderstorms. And, you know, most of the turbulence from that is in or near those thunderstorm cells. And so you will look to go around the entire area or find a spot between cells to fly through.
The Intertropical Convergence Zone -- I said that correctly now -- is sometimes pretty wide and long, and so it can be difficult to go around the entire thing, so usually you're going to be finding an area that's free of cells and go through that area.
Tracking radar signals
MARGARET WARNER: And how good is your information as you approach it about exactly where the real trouble spots are?
BEN BERMAN: Well, it's good and it's bad. The radar that you have in your aircraft can show you where these cells are. But, for instance, in the case of this aircraft, approaching the area at night, it's hard to tell if you're going to be over the storms or in them when you approach them.
And so you can see them on radar. You'll see the lightning flashes if you're on top of them. But at night, you'll be peering forward through the windshield trying to get into the darkest spot to see if the tops of the clouds are below you or above you. And sometimes it's not clear.
MARGARET WARNER: So fourteen minutes after, somehow a signal is sent that they've headed into this zone. An automated signal comes through or a message saying electrical system or circuit malfunction. Now, what does that tell you?
BEN BERMAN: Well, this is a kind of an automated message that the modern airliners send to the maintenance departments back at the airline. And it says, "Hey, there's something wrong with the plane that needs to be attended to when we arrive, so get the parts ready and start getting to deal with it."
So this airplane sent out a message. We don't know at this point what kind of a message it was. There is more detail that has been reported by the aircraft; it's just not been released publicly.
MARGARET WARNER: So you think there is more data, more information?
BEN BERMAN: I think there is some detail about it, yes. I'm not sure how good it is.
But one of the things that I think about is that this could have been a consequence of whatever befell the aircraft. It might be a consequence of some mechanical problems that it had, weather problems, turbulence, or structural failures. Those could result in an electrical failure and then send the message. Or it could have been the cause of it. It could have been a massive electrical problem and then the thing sends a message.
No message from the pilot
MARGARET WARNER: So there's no mayday, no distress call from the pilot. What would explain that?
BEN BERMAN: Well, that tends to suggest that something happened fairly quickly. Like I said, the pilots can pick up the satellite phone and get in contact with somebody fairly quickly, within a minute or so.
It's not the first thing you do if you ran into trouble in an airline. The first thing you do is control the airplane. Then you deal with the consequences, make sure everybody is as safe as they can be.
MARGARET WARNER: What do you think the prospects are that this wreckage will actually be found, that the black box will be found, that we'll really get more information about what happened?
BEN BERMAN: Going back in my history of accident investigations, I think that the likelihood of finding the wreckage and black boxes is fairly good. Right now...
MARGARET WARNER: Despite the vastness of the area?
BEN BERMAN: Exactly, it's a vast ocean. Eventually, probably, they'll find some wreckage on the surface of the ocean. Then they'll scan with sonar and look underneath the ocean. It might be very, very deep down.
There have been some tremendously successful and difficult recoveries of recorders using deep sea submersibles down at the bottom of the ocean. This may be deeper than it's ever been before, but they'll probably get those boxes.
MARGARET WARNER: And, briefly, does the black box emit some sort of signal to help them find it?
BEN BERMAN: Yes, it gives out a pinging signal that sonar can listen into. It's good for about a month and not for too much of a distance, so they've got to get close, and they've got to do it fairly soon.
MARGARET WARNER: How close?
BEN BERMAN: It's said that it's within two miles, so that's pretty close.
MARGARET WARNER: Got to be pretty close.
BEN BERMAN: Yes.
MARGARET WARNER: Ben Berman, thank you so much.
BEN BERMAN: You're welcome.