Hopeful had ready to throw right back at her. And he has the best job and the bravest taste buds of anybody on television. Anthony bourdain, joining us this hour. Good evening, everyone, welcome to this special prime time edition of the lead. Tonight in our world lead officials are tightening that search zone to the smallest area yet. Just about 18,000 square miles, far narrower than just the day before. Were now on day 35 since flight 370 vanished with 239 souls on board as we speak. As many as 15 airplanes and 13 ships are taking part in the search zone which is a full 12 hours ahead of the eastern u. S. Time zone. This, after a possible signal was once again discovered in the water. That is a fifth time that a signal has been picked up. At this hour were waiting the results of the analysis on that as our renee marsh reports. The team came by the latest break in the mystery using very different, perhaps even more efficient technology. Reporter the search for flight 370s black boxes intensifies and the ping count may have gone up again. An australian orion aircraft over the ocean shield, dropping sonobuoys. And at least one of them got a hit. A possible fifth ping detected where the ocean shield already picked up four. That could be a confidence builder. The fact that it is picked up by a sonobuoy which is probably less well equipped to detect that signal than the pinger locater, that would indicate that perhaps it is still a pretty strong signal. Reporter the acoustic data is being analyzed but they say it is potentially from a black box source. The sensors are deployed at least a thousand feet under water but only work for eight hours. Sonobuoys usually used to detect submarines were not designed for this type of mission. The ones that im familiar with generally have very poor response to frequencies as high as 37 kilohertz, theyre normally used for one or lower. But that is not to say there have not been changes made. Reporter the search area around the ocean shield continues to intensify, the british shield has pulled out of its position to the southwest and is now focusing on where the ping has been detected. But crews listen for more pings to shrink the search zone. A smaller zone is necessary. The underwater vehicle can only search 43 square miles a day. That means the roughly 100square mile area where the pings were detected would take nearly two weeks for the bluefin to search. The u. S. Navy ship Caesar Chavez is on its way to participate in the fiveweek long search. Renee marsh, cnn, washington. The ship that renee mentioned is part of the navys seventh fleet. That is also the fleet that is operating the pinger locater, the one that detected possible signal locations in the ocean four times already. So lets go to commander William Marks who joins us on the phone. The spokesperson for the seventh fleet. Commander marks, i have to ask you have any new signals been discovered in the last few hours . Not in the last few hours, it is 10 00 in the morning here, i got the information on the potential hit for the australian p3. Ill let them announce that, i dont want to steal their thunder, but they have a few tricks up their sleeve. If that was the case, they will report on that one. I just got out of the morning brief, the last few hours, were analyzing the fifth pinger hit. And remember this is a continuous 24hour operation. So in essence we never stop looking. It is completely around the clock. And commander, did this fifth potential ping factor into the decision for the search area yet again today . Well, i do need to let the Australian Government make their announcement. But you know it is shrinking every day. And you know, it is pretty incredible if you look at where we started which was virtually the entire end ocean now getting it down with essentially a couple hundred square miles. Pretty miraculous. But that being said it is very important to shrink this down as much as possible because the bluefin21 sonar is very slow, deliberate and methodical in searching. Whereas the tpl, you simply drag it through the water and it listens to any signal that it might receive. The bluefin21 is a side scanner and actually paints the picture of the bottom of the ocean so it is much more slow and deliberate and cant cover as much area. So even right now as small as weve gotten in this area it still is really not small enough to deploy the bluefin yet. We want to shrink it down as much as possible. And finally, we want to utilize the last couple of hours or even days on the battery life with the black boxes. So were going to continue to search with the tpl for now. Commander marks, good luck with the search, thank you so much. Lets bring in tim taylor, sea operator, and david souci, analyst and author of the book why planes crash theyre here with me. And cnn analyst, miles obrien. Tim, i want to start with you. The fifth ping is Building Confidence increasing the data map that could bring the searchers to the source. Continue the pings, as long as you can get ping. The av work and ultimately rov work on this site, we have forever to do. We have limited days or hours as commander marks said on this. So get as much as you can until it stops because you cant go back. And once they stop with the towing the tpl and they start the av operations they cant do one or the other. So you can only do one of those. It is not like you can do these simultaneously from that platform. David, what do you think . Just keep doing what theyre doing . More of the same, im really getting a little concerned about the battery life. Were already on borrowed time. The fact that they have narrowed down where theyre looking for the pings and theyre not getting the pings makes me a little concerned that we may have lost that battery. Miles, we also heard a different report about lower altitude. The plane going down to a lower altitude, 5,000 or 6,000 feet. I wanted to ask you about that. At those lower altitudes if the plane was there could cell phones have worked . You know, there is a lot of twitter traffic about the cell phones and why there were no cell phones. I think people remember 9 11 and all the calls that were executed on that day. Some of those calls were done by satellite phones that were built into airplanes at the time. And you dont get them on the airplanes anymore. But in this case, this flight path. It would have been highly unlikely that they would have been able to reach a cell tower. Because even if you accept that altitude, which im very skeptical about because weve heard so many numbers, none of it makes really a lot of sense to most people who have looked at it. But even if you accept for a moment that they were at 4,000 feet over the strait of malacca at that period of time, probably too far away from cell phone towers to get off a call. That is why as far as we know, why there is no communication from the people in the back. All right, tim, lastly, assuming that they do not hear anymore pings, and were all waiting for the moment when they launch this under water drone, the bluefin 21, how many days do they go, do you think, of not hearing any pings before they launch it . If i was on the operation i would give it three or four days . Three or four days of nothing today, nothing today. Again, it is very inexpensive to wait that amount of time versus the overall size of this project. When they start to do autonomous work and rov works it could be months. I mean, they could find it in a couple of weeks, days or less, but the rov just takes pictures. You can take pay loads and take pictures of the wreckage, but you cant do anything with it. You have to bring other assets to help do the work. All right, well have much more on the information on flight 370. And the Malaysian Air force had an idea that the plane made the turn and scrambled jets to find it. Then, why the intense search on the other side of the country . Plus, setting the record straight on the final communication on the plane as police play the recording for other malaysian pilots to find out who was speaking. That update coming up next. So ally bank really has no hidden fees on savings accounts . Thats right, no hidden fees. Its just that im worried about, you know, hidden things. Ok, whys that . Well uhhh. Surprise um. Well, its true. At ally there are no hidden fees. Not one. Thats nice. No hidden fees, no worries. Ally bank. Your money needs an ally. 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Theyve got a lot of great ideas. Like smart pick ups. Theyll only show up when you print a label and its automatic. We save time and money. Time . Money . Time and money. Awesome. Awesome awesome awesome awesome awesome awesome awesome all awesome i love logistics. K welcome back to the lead, continuing our world lead over the past month weve seen the backtracking, the misstatements, some shiny examples of terrible bedside manners from malaysian officials. And even though theyre denying it now, tonight we now know the malaysians may have had a bead on the flight when it vanished but didnt tell anyone for days. Now, what we know about the planes path to the unknown. Reporter it has been one of the lingering mysteries of flight 370. What happened in the first few hours after it went off course. Now were learning that the plane disappeared from radar for 120 nautical miles after it made that turn and crossed over the peninsula. A senior malaysian Government Official and a source involved in the investigation tells cnn the plane must have dipped in altitude to between 4 and 5,000 feet. A possible sign the pilots were at the controls. But it is still unclear if the plane was in some sort of trouble. Whether they were purposely evading detection or whether the malaysian radar system failed somehow. They may have been switching pilot responsibilities at the time. So whatever event happened, whatever was planned, whether it was nefarious or mechanical it happened as a result of that transponder and that acars getting shut off. What is clear now, the captain was the last person on the jet, not his copilot, to speak to air traffic controllers, telling them good night, malaysian flight 370. The sources say there was nothing unusual about his voice which portrayed no indication he was under stress and no third voice is heard. And just today, more than a month after the flight disappeared, were learning Malaysian Air force search aircraft were dispatched soon after the airline reported its plane missing. Malaysian sources told cnn heading for the strait of malacca and the south china sea, malaysian authorities first concentrated their search on the south china say. There were indications that the plane turned suddenly westward from the malaysian course. And the malaysian government denied in a tweet that any Malaysian Air force aircraft were scrambled. I am suspicion of the information they provided. I think the most likely scenario is that they detected them on military radar, they scrambled those jets and either couldnt locate it or some other problem developed. But our source says the air force did not inform the rest of the malaysian government until three days later, march 11. A source involved in the investigation told cnn. Joe johns, cnn, kuala lumpur, malaysia. And i want to bring in our analyst, david souci, and miles obrien, and tim taylor. I want to start with you regarding the claims the Malaysian Air force did not notify the rest of the government until three days later that jets had been scrambled to find this plane. They didnt know it was flight 370 at the time. If it is true, and obviously there are a lot of contradictory voices on this, but if it is true how critical would that information have been in the early days of the search . Well, obviously, and im not the aviation guy. But they did searches in the south china sea. So they started the search off in the wrong direction. Completely wrong body of water. Right from there i think you have a whole different direction where it would have gone, where it would have saved days. And they would have gotten to the south indian ocean a lot faster. And david, where does the communication protocol start . If theyre local, it translates locally. When you say this is the aircraft, and you say good night, and call ahead and talk to the receiving tower and you say there is an airplane heading your way. They then wait for that airplane to come in. If the airplane doesnt show up that is when they start asking questions. And in this case, it was hours and hours and hours after. If there was an airplane not communicating they may have had the wrong frequency, so in this case, they start to raise questions about whether or not other planes can hear them. So it does take a bit of time. So six or seven hours, i cant understand that. Bizarre, indeed. Miles how fast would fighter jets have been out there . Well, that would have happened quickly post9 11. The system is pretty well springloaded for a primary target of that nature just moving unidentified and not responding. What is interesting, though, is this gap is a really key point. If you wanted to do something, if you wanted to go missing this is the time to do it. Because one controller assumes the other controller is talking to you and viceversa, so there is this period of time where you could turn off your transponder and nobody would notice. But if it were one particular area, the alarm bells would come up because you would disappear from the screen and you would start to call people right away. So the handoff is a key time if you were trying to go missing put it that way, that would be the time to do it. And david, lastly, there has been so much back and forth from the final words from the cockpit. We now know it was the captain saying good night, malaysian flight 370, not the copilot. Quickly why is it so important to get it right . What is important to me is who is the pilot flying and who is the pilot not flying . This indicates because there were 12 minutes between the last communications it tells me that the control of the aircraft switched. And if it is something nefarious, if there is something going on above and beyond anything mechanical that would be important to note as we go forward. All right, david souci, tim taylor, miles obrien, thank you so much. All right when we come back, it is now day 33 for the search for missing flight 370. Well go live to perth. And next, one of the top cabinet members resigning, after the botched obamacare rollout. Was she pushed . [ female announcer ] with five perfectly sweetened whole grains. You cant help but see the good. This is mike. His long race day starts with back pain. And a choice. Take 4 advil in a day which is 2 aleve. For all day relief. Start your engines its red lobsters lobsterfest all promotions the years Largest Selection of lobster entrees, like lobster lovers dream. Hurry in and sea food differently. Go to red lobster. Com for ten dollars off with purchase of two lobsterfest entrees. You gotta reel it up now,buddy. It. Creel it up. T up, [father] reel it up,you got him on there. Bring him in. Is that a bass . [boy] yeah,i got a big bass. [father]bring it up. Keep reeling. Keep reeling. Cmon, where is he . Whoa you caught that all by yourself . [boy] yeah [father]how old are you to catch that . [boy]three [father]youre three years old . Show me how many fingers that is. Air traffic controllers, air traffic cont. Welcome back to the lead, im jake tapper, more on the investigators at the Australian Air force base who are busy analyzing the under water detector to determine if it came from the black box of flight 370. This as searchers zero in on the area where the signal was detected. Lets go live to cnns erin mclaughlin. Erin, has there been any change in the size or scope of the search area . Reporter well, jake, they continue to refine the search area today. By another 500 square miles, really a quarter of the size of what it used to be, which has allowed them to intensify the efforts of some 15 aircraft and 13 vessels out combing the waters for any signs of debris. But it has to be said after hours and hours and hours of searching were now some 35 days since the plane went missing, not a single, physical sign of the plane has been found. So the focus of this search effort very much on for the elusive pings. Overnight, they have been analyzing this data that they have obtained from one of the sonobuoys, one of the dozens or so that they have parachuted out onto the water. They said they hope to get an update on that today. Meanwhile, the australian vessel, the ocean shield, continues to be out there combing the waters with the american operator, the towed pinger locator, making detections, four so far which have given so much promise to the search area. We also know the british vessel, the hms echo with the equipment is joining in that effort. Really, the goal here is to obtain as much information from the pings as possible to be able to narrow down a potential search field so that they can deploy the underwater Autonomous Vehicle provided by the united states, the bluefin21 which is capable of going underneath the ocean and finding physical wreckage. But at the moment were not at that stage yet. Erin mclaughlin in perth, australia, thank you so much. And when we come back, Hillary Clinton ducks just in time as a shoe is hurled at her head in las vegas, you may be surprised at her Quick Reaction coming up next. Ameriprise asked people a simple question in retirement, will you outlive your money . Uhhh. No, that cant happen. Thats the thing, you dont know how long it has to last. Everyone has retirement questions. So ameriprise created the exclusive. Confident retirement approach. 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