i believe they are. and the only thing that i would think would be somewhat better would be to have four, five, or six if they could afford them of the bluefin-21s or other autonomous underwater vehicles so they can search the targeted area much quicker. only having one or two units makes it much more time consuming. colleen, once they bring up the bluefin-21, it takes about four hours to review. walk us through what they do to see if they have spotted something. well, i would actually like to defer to gene because you re talking about image interpretation and often these images don t look like a photograph. and that s that s the key thing to understand. you re looking at returns of sound that is bouncing off the object and coming back and there are big shadows behind the object where the sound doesn t go and there could be those shadows could be hiding something. so what you have to do is you
satellites. reporter: radar picks up the plane s track along the crest of the sierra, nevada mountains. following a trail fossett hiked as a teenager. colleen keller volunteered in the search. before they could really pursue the evidence, they were distracted by another piece of evidence that popped up which was a visual sighting out in the desert. that was tempting because whenever somebody says they see a plane people put credence in that. reporter: that came from a ranch hand in the area who tells authorities the plane flew over him while he was standing on his porch, 15 miles from where fossett took off. he said the plane was flying pretty low, just about 1,000 feet. the tip changes everything. it was terribly distracting. they never went back and looked at the previous evidence they had. they focused everything on the few new piece. reporter: the search area suddenly shifts dramatically from the mountains, about 60 miles northeast to the desert.
colleen keller is joining us once again. she s a senior analyst at metron inc, a defense contractor that helped find air france flight 447 back in 2009 after it crashed. talk a little bit, colleen, about the challenges that this bluefin-21 is facing right now under water. it s going around in some potentially pretty treacherous areas on the ocean floor. well, the biggest concern that we have, wolf, is the topography on the bottom is not very well known. i know they ve said that it s rolling terrain, it s relatively smooth and silty. but until we get down there, we may be in for a big surprise. this could have a big impact on operations. likely they re going to float the bluefin higher above the surface than they d like to because they re trying to be cautious. they don t want to run into anything. that s going to impact the effectiveness of the vehicle. won t be able to get the same resolution it could if it were floating lower to the surface
we weren t in the right place to detect the pings. they went through two phases of unmanned underwater vehicle searches. and then the third phase is when they actually found it. here, we re just starting the unmanned phase. so we may, you know, be in for the long haul there. for the air france search, the underwater vehicles were deployed in two to three-week intervals and in between, they waited maybe a couple months before they decided where to go back next. here, we just have one area and we re just going to troll the heck out of that area. so, it s a little bit different in that sense. colleen keller, thanks very much for joining us. thank you, wolf. all right. this just coming in from the white house. president obama has spoken with the russian president vladimir putin this afternoon on the crisis in ukraine. our white house correspondent is joining us now with details. what are you learning over there, michelle? this is obviously a very tense situation.
here. i mean, we want to find the wreckage. we want to do it as methodically as possible and expeditiously, but at this point, we re just recovering wreckage. we re not rescuing people. so we should do this cautiously. a lot of experts have suggested there s some thick silt at the ocean bottom over there on the floor that could really complicate this search. what are you hearing about that? i really don t know what the bottom s like, but it could very well be silted over and the box could be partially buried, but the fact we re hearing the signals tells me at least something s protruding and working properly and hopefully visible to the submersibles. colleen keller, always helping us. thank you very, very much. upcoming, we ll have more on the mystery of flight 370. that s coming up. also an alleged military buildup near the ukrainian border. cnn goes in search of what firm could be an invasion. stay with us.