NBC News   |  March 24, 2014

How Tow Listeners Detect Pingers

Robert Hager, who covered aviation for NBC News for 25 years, explains how a Towed Pinger Locator detects a black box underwater.

Share This:

This content comes from Closed Captioning that was broadcast along with this program.

>> lauer: let´s turn now to bob hager, who covered aviation for nbc for 25 years. bob, good morning to you. so, the malaysian authorities are now saying they´re sure this plane is in the southern indian ocean . that is the tragic part of this. the question is, how do you prevent something like this from happening again? and to be able to do that, you have to figure out what happened on that flight.

>> hager: yeah, you need to know a lot more. and what we don´t know is why he said that. i assume that means they made a positive i.d. of one of the pieces of wreckage. but that´s just the beginning of it. i mean, you really need these black boxes , hopefully, to tell you what went on in the airplane.

>> lauer: and to have a chance at finding the black boxes that are pinging now for about 13 more days, until the batteries run out, you´ve got to get a ship above that plane and you´ve got to reverse-engineer. you´ve got to get a piece of wreckage, and then you have to go back and think, "where could that have come in the past 17 days ?"

>> hager: yeah, it´s a long process, so you got to tow this listening device from behind the ship. and i think they got a little more time. they got a little more time to -- the pinger will probably last a little longer than that, you know, hopefully, but still it´s a big job. and then if you get the ping, you´ve got to locate it. oh, there´s a shot of it.

>> lauer: there´s the towed ping locator right there.

>> hager: that´s a listening device, yeah. and then you´ve got to get, if you find -- if you hear the ping, and that will tell you -- zero you in on where it is down on the floor of the ocean. then you´ve got to drop a nonmanned sub, a robo sub, down there -- small, 6, 7 feet -- with a camera in it and look and see if you can actually see it.

>> lauer: and you´re talking about depths -- we´ve heard that the southern indian ocean in that area can be anywhere from a couple of thousand feet up to 14,000, 15,000, 16,000 feet.

>> hager: very, very difficult job. but one thing, i think, to think about -- with the passage of this kind of time, nothing bad coming out about the cockpit crew so far, you have to go back. you can´t eliminate completely, as they tended to do in the early days , the idea of some mechanical problem causing this.

>> lauer: and yet why, though, wouldn´t that crew have had a chance to issue some sort of a mayday call during that four, five, six, seven hours?

>> hager: yeah, well, here we´re getting pretty speculative. but if was it was smoke or decompression or something like that, one of the things you do in smoke is you shut down all the electrical equipment right away and then put the things back on, one fuse at a time, to see if you can locate the trouble. so that would explain, you know, cutting all communications. it´s a possible scenario. you just can´t eliminate anything, because we know so little.

>> lauer: you stick with us for a little while.