Transcript for Passengers of Flight 370 Face Scrutiny
-- -- up -- new York at a CBC news digital special report lost and still not found more twists. In the search for Malaysian air flight 37 the search expands to 25 countries and nearly two million square miles. Officials announcing it is possible the plane's transponders and other assistance could have been shut off before. The co pilot signed off. ABC's Devin Dwyer -- developments in the search joins us now with the details -- -- good afternoon again this is just a massive search new direction now this morning but still no focus and where they're looking. This is Malaysian officials say they're starting to give greater scrutiny to the passengers. And those pilots. Today new questions about the last human contact -- Malaysian airlines flight 370. Investigators now say it's the voice of the co pilot for -- of dual Hamid in that final transmission to air traffic control. His words all right good night getting a closer look -- look at the voices and a look for stress in his voice to see. -- somebody had a gun in his head was being told to do something Malaysian officials of giving contradictory information about when the planes to key communications systems turned off. Investigators say if they shut down separately several minutes apart. It would suggest a deliberate act if you're potentially shutting -- those systems only one reason is to basically vanished may be very difficult -- Investigators are focusing in on the pilots personal lives including reports that had -- had broken safety standards in the cockpit. At the home of captains -- her -- a -- shock police confiscated two laptops and his home flight simulator seen in this YouTube video he posted online -- I cannot imagine him doing anything -- Himself. The passengers. The property. Satellite data suggest the plane flew one of two possible paths north toward cossacks -- or south toward Australia. US officials say the plane most likely ran out of fuel and the south Indian Ocean where Australia's now coordinating the search. And if the plane did in fact crash into the ocean only lighter weight items like a seat cushion or insulation would still be floating on the surface so they're looking for that. Let's heavier items like the plot black -- -- -- would obviously have sunk to the bottom of the ocean and that's. Two miles deep there in the Indian Ocean dent in that would be in a crash scenario but authorities are they still considering the possibility that plant back could've landed somewhere just simply undetected. Well they haven't ruled that out yet definitively mean there's still a miniscule amount of hope by US officials have told ABC news. But they do say that if it flew north on that northern track up over -- it is very unlikely that it would have been able. To dodge radar detection -- heavily militarized areas that are scouring those skies. And even if it did manage to get past some of those it's detection systems it would be very difficult for a pilot to land that -- -- triple seven. All -- again. All right ABC's and -- -- finalists in the search -- thank for that to from more on the ever expanding search. For the plant want to bring in the NTSB's former director of aviation safety Tom Holler from Washington Tom thanks for being with us today. Some -- statements from Malaysians why can't they pinpoint exactly when these communication systems were turned off. That I don't understand you know given the times past they shouldn't very definitive time -- to act when everything happened. The actual timing of it the whole nine yards. This back and forth about -- -- didn't happen before after. That's very disconcerting I don't know why it's taken so long put that the other. Is isn't a matter that it has to be registered -- are receiving. Piece of equipment or -- exactly. You know we've been learning so much about how transponders. -- satellite systems have been working over the past couple of days. Is there still the human element that is involved. -- terms of the transponders that should be recorder on the radar tapes you -- exactly when the transponder stopped. And certainly you have take a look at movement of the time what society and the clock with the correct things like that. But that can be done fairly quickly. -- looking at all the data yes you have to verify it. But it's been over a week and -- shouldn't put together days ago. These information systems to be constantly changes are increasingly beginning as far as when it was turned off and that the secrets as you can point out there would affect for a longer sure that these systems were shut out deliberately right. Well that that's what happens that with when the sequence changes that changes -- scenario what could've happened. Certainly it appears that after all communication was lost an airplane made to turn the west. That there were a series of maneuvers that would. We're just one heading change entered in -- system before the crew was incapacitated. So what happened here this makes no sense and that's why it's very important to know the exact timing of all these events that helps give you -- clue. Now doesn't us -- help you find the airplane that's her chest ago -- But does give an idea what else you may want to look for all possibilities are on the table as the Malaysian authorities and other countries that have been conducting their own sort of investigation -- at a time minds of these clues. Have been putting out their for possibilities. For what might happen to this plane. Why today in European and do you think Malaysian officials are focusing so much attention on the pilots themselves their history communication at whether they had sort of made a request to work together on this particular flight. Well obviously. -- You need look at everybody on the airplane look at the -- first loser in the cockpit and fly the airplane -- -- the best right there to control. However he can't stop -- the pilots you need to look at everybody on that airplane that could potentially fly the airplane. -- previous flight experience they've been doing research on the triple -- and have been doing other research and aviation. So you need to -- -- everywhere on the airplane and start eliminating people who are. Obviously not candidates have taken over the flight. And also take what people who may have been the start doing some deep background -- on them. -- if you can explain to me than this a -- the communications system how does that work. Basically it's like a text messaging system. And it's their for the crew to get information from the ground up they can receive weather information they receive air traffic information. The -- information to receive. Coming in to land. That's from identity card system. All the -- formations coming up and down. -- just a way to easily communicate information back and forth. The ground -- the new flight plan or you can tell what changes in flight you can say because of weather we're having two. Deviate to a different airport -- do all that communication with your company through the -- car system rather than using the radio. Explain -- them is that a limitation of the satellite system the communication. System back and forth between the plane. -- radars then how these two arcs were creative. You talk somebody else but the two -- I don't quite understand how the two or recoveries quite frankly at this is all whole new ball game for the into his beer myself. We haven't come across this technology before. -- understand that even though the eight cars system can be off the data collection systems off. It will still as the satellite. Passes overhead it says I'm here. And through that information variables accretive to arts and exactly how they got into our exes. Beyond my expertise units and is finishing point that so there are different technologies that are used for various airlines in various countries. There is a mean everybody has options. Boeing makes the airplane with a certain amount of standard options that you could actor's plea of a vendors out there who have other things to provide -- -- entertainment systems communications systems. Or in this case -- the management system aircraft. That they will provide this service so every airline can choose their own vendors for certain services. Has that ever -- frustration with the NTSB or other countries -- for trying to. Understand when something like this would happen. Oh certainly meet every time we get -- -- and you'll learn things new and certainly we've learned some new things here. And we expect every -- is different. How other manufacturers -- different the customer options are different. And each time learning experience is there ever been a push to standardize this. There's some things are very much standardized when -- get into. The transponder systems the other systems aircraft communications as -- very standardized. But when you get into things that are not apps are required for flight then you get a little bit customer behavior you're. -- -- -- US officials are focusing on the southern court or of this search area. That is where Australia is putting a lot of their efforts as well why do US officials believe that that in fact the -- the likely location for this well I. Speaking for myself I think it's likely because if you had ignores you're going into areas -- lots of radar sites and those sites would have depicted the airplane those transponders off. The radar would sweep it would -- the primary return from the airplane it could be -- was heading -- So it given that we haven't found it there's no indications -- any radar. Contact with the going north I believe it's prudent -- so does the passage of time. Make anyone yourself perhaps as well because even bought an investigation before seem unlikely that in effect this may not be found -- -- extended period of time. Well it makes it more difficult to I believe it will be found that -- probably have now is that the airplane crash in the water. And there's been floating debris you've had a week for the debris to be moved by winds and currents and -- much further -- than it was before. So even we find it is can -- a lot of effort. To backtrack that data. To determine OK we know were the parts are frowned. Now where were and they when the airplane hit the water announcement takes some effort because -- times in Europe Pena how much longer do you think these. More than two dozen countries will be putting up this kind of effort in this kind of activity energy into finding this search. It's hard to say but I think given the the publicity of this Ian -- -- people I suspect -- go on for quite some time but it's difficult when you don't know where to look just to keep sending ships and planes out searching. There's just make it difficult. Another arrest it's gonna be when the wreckage found its most likely going to be in deep water and finding people pay for that recovery is going to be difficult and so. There have been a lot of bizarre theories that have floated out there again base in the fact that there's been a prolonged period of time ten days now. Are there any that are sticking out to you in your mind and again everything is on the table of course but are there any better just so. In probable that you could almost wiped them off the list of possibilities. Well I. I think you you don't wanna do that as an investigator you leave everything on the table to the of the facts to taken off. And right now we don't have a lot of facts. To me I think terrorism further down on my list but tomorrow we might find some data that pulls up higher analysts. Right now we don't know why somebody would do this. What's the motive behind it that's to be difficult to know. Possibly -- pin down who the person might be or something. Then we could get a better idea. Had this happened to an American aircraft with the NTSB be handled this differently then with the Malaysian military's handling. NTSB would be providing -- a lot more data. The NTSB does -- a lot the activists ignition is what we do. We've done it for many years were well rehearsed -- -- that the process. The Malaysian government -- much smaller and -- have never done this before. So if this of the NTSB I think you'd be finding a lot more factual information being provided a lot more solid information being provided. So we wouldn't have this going back and force in terms of what -- is really out there. And that's the problem we have this. I every day -- seems like there's a shift in the data and that's concerning. Tom hotter former aviation safety director with the NTSB in Washington with us now top thanks so much really appreciate that. Thank you and of course you can give over the story in real time download in the ABC news -- star in this story for exclusive updates on ago. For now I'm down -- New York with the CBC news digital special report.
This transcript has been automatically generated and may not be 100% accurate.