CNN CNN Newsroom March 26, 2014 14:22:00
The pinger locator with the fin on top is towed slowly through the area. it can go down to 20,000 feet below the surface. for hours and miles at a time, it is listening intently for the black box's signal. >> how far away can it be? >> the outside edge is about 2 miles, a mile and a half to 2 miles away, it can detect the sound. >> the signal would come up through the umbilical. you can see here is a cable. it runs up through the umbilical. it comes into our receiver unit. we have speaker on here and all the power buttons and we can adjust the frequency it is looking for. out of this box, we h...