0:00:10 > 0:00:13This is the inside story of a disaster
0:00:13 > 0:00:15that seems unimaginable in our time.
0:00:18 > 0:00:22How can an airliner full of people vanish without a trace?
0:00:27 > 0:00:3126 nations joined the hunt for Malaysia Airlines Flight 370.
0:00:36 > 0:00:40It was almost a relief to narrow it down to a hemisphere.
0:00:40 > 0:00:41It's a daunting task.
0:00:45 > 0:00:48Family members should prepare themselves for the worst.
0:00:48 > 0:00:50When MH370 disappeared,
0:00:50 > 0:00:54the families of those on board were plunged into a nightmare...
0:00:55 > 0:00:57..and the world needed answers.
0:00:57 > 0:01:00SHE WAILS
0:01:00 > 0:01:03This film is a forensic examination of events.
0:01:03 > 0:01:05It follows the scientists and engineers
0:01:05 > 0:01:09who unearthed a trail of clues where there were none.
0:01:09 > 0:01:12I was delighted that the calculation had worked
0:01:12 > 0:01:14but, of course, you feel the...
0:01:14 > 0:01:17the depth of this, the severity of it.
0:01:17 > 0:01:22It reveals the location where their data suggests the plane went down -
0:01:22 > 0:01:24a location yet to be searched...
0:01:26 > 0:01:29..and pieces together what might have happened on board.
0:01:29 > 0:01:32..and that flammability hazard exists...
0:01:34 > 0:01:38Finding MH370 is fast becoming
0:01:38 > 0:01:41the most challenging search in human history.
0:02:02 > 0:02:05Kuala Lumpur International Airport -
0:02:05 > 0:02:09the gateway to 43 countries across Asia and beyond
0:02:09 > 0:02:13for tourists, business travellers, people going home.
0:02:18 > 0:02:21On Friday 7th March, 2014,
0:02:21 > 0:02:25the pilots of Malaysia Airlines Flight 370 to Beijing
0:02:25 > 0:02:28were filmed crossing from landside to airside.
0:02:30 > 0:02:33Whatever these men did in the hours that followed,
0:02:33 > 0:02:35or whatever happened to them,
0:02:35 > 0:02:37lies at the heart of this mystery.
0:02:49 > 0:02:53The relationship between pilots and air traffic controllers
0:02:53 > 0:02:54is crucial to flying safely.
0:02:55 > 0:02:57It's a very important relationship.
0:02:57 > 0:03:00Any time you try and get an aircraft from A to B,
0:03:00 > 0:03:02it's a matter of teamwork.
0:03:02 > 0:03:04And air traffic control are a vital member of that team.
0:03:07 > 0:03:09There's a real bond between controllers and pilots.
0:03:10 > 0:03:14They understand the job that each other is doing
0:03:14 > 0:03:16and it's a really, really important part
0:03:16 > 0:03:18of the safety culture of aviation.
0:03:24 > 0:03:27So how did MH370 slip the surveillance technologies
0:03:27 > 0:03:30the air traffic controllers rely on?
0:03:31 > 0:03:35These are the actual recordings of what happened this night.
0:03:47 > 0:03:52Just as the flight had so many times before, at 12.41am,
0:03:52 > 0:03:57the Malaysia Airlines Boeing 777 lifted off into the night,
0:03:57 > 0:03:58bound for Beijing.
0:04:00 > 0:04:05On board were 227 passengers and 12 crew.
0:04:06 > 0:04:08It was a very normal flight.
0:04:08 > 0:04:09Everything was calm, ordered.
0:04:09 > 0:04:12It's exactly what you would have been expecting on the day.
0:04:12 > 0:04:14There was no drama.
0:04:14 > 0:04:18There was no reason to think anything unusual is happening.
0:04:22 > 0:04:26Stephen Landells is an experienced 777 pilot
0:04:26 > 0:04:27with a comprehensive knowledge
0:04:27 > 0:04:30of the state-of-the-art systems on board.
0:04:32 > 0:04:36'This is a Boeing 737-800 series.
0:04:36 > 0:04:39'This cockpit is very similar to the 777 cockpit.'
0:04:41 > 0:04:43Positive climb. Gear up.
0:04:45 > 0:04:47Like all modern passenger planes,
0:04:47 > 0:04:51the Boeing 777 is a technological marvel.
0:04:51 > 0:04:56In service for 19 years, its safety record is excellent.
0:04:56 > 0:05:00Its systems are so advanced, it can virtually fly itself.
0:05:02 > 0:05:04A lot of the systems are automated.
0:05:04 > 0:05:06But it is just a computer.
0:05:06 > 0:05:08You use the automatics a lot,
0:05:08 > 0:05:09but have you to control them
0:05:09 > 0:05:11and make sure they're doing the right thing.
0:05:11 > 0:05:13And that's what the pilots do.
0:05:16 > 0:05:19The pilots can communicate from anywhere on the globe
0:05:19 > 0:05:23using very high frequency and high frequency radio,
0:05:23 > 0:05:26a text messaging service called ACARS
0:05:26 > 0:05:29and a satellite link for voice calls and sending data.
0:05:31 > 0:05:35I've been sitting over Greenland, listening to the HF radio,
0:05:35 > 0:05:37and I've heard someone having a conversation with Mumbai.
0:05:39 > 0:05:41When it comes to navigating,
0:05:41 > 0:05:44the aircraft follows a route that's already been programmed in.
0:05:46 > 0:05:50You'll load your route into the navigational computer.
0:05:50 > 0:05:51And you can actually load that
0:05:51 > 0:05:54all the way from your start point to the end point.
0:05:58 > 0:06:00Less than a minute after take-off,
0:06:00 > 0:06:04the crew of MH370 were told to modify their route to Beijing.
0:06:16 > 0:06:19The crew were told to turn right on a more direct route to Beijing,
0:06:19 > 0:06:22via a waypoint called Igari.
0:06:22 > 0:06:25Waypoints are code names for coordinates on the map
0:06:25 > 0:06:29that air traffic controllers and pilots use to navigate.
0:06:31 > 0:06:33I'm going to add Igari.
0:06:33 > 0:06:36I-G-A-R-I.
0:06:36 > 0:06:39'The airways, the motorways in the sky, are...
0:06:39 > 0:06:41'They're set routes.
0:06:41 > 0:06:44'And they are defined by waypoints.'
0:06:46 > 0:06:50Near Igari, responsibility for MH370
0:06:50 > 0:06:53will pass from air traffic controllers in Malaysia
0:06:53 > 0:06:55to their counterparts in Vietnam.
0:07:04 > 0:07:0726 minutes into the flight,
0:07:07 > 0:07:10the last ACARS message sent automatically from the aircraft
0:07:10 > 0:07:13showed normal routing all the way to Beijing.
0:07:20 > 0:07:25As MH370 headed out over the South China Sea,
0:07:25 > 0:07:27air traffic controllers were tracking it
0:07:27 > 0:07:30using a technology developed in the 1930s -
0:07:30 > 0:07:32radar.
0:07:34 > 0:07:37It was developed mainly by the British for the Second World War
0:07:37 > 0:07:40as a device for protecting the UK shores.
0:07:42 > 0:07:44The technology has changed a lot,
0:07:44 > 0:07:47but the concept has remained very much the same.
0:07:48 > 0:07:50Well, this is a primary surveillance radar,
0:07:50 > 0:07:53very similar to the one that's in Malaysia.
0:07:53 > 0:07:57And you can see the bottom half of that is the main radar itself.
0:07:59 > 0:08:03Air traffic controllers used two main types of radar.
0:08:06 > 0:08:08Primary radar detects where aircraft are
0:08:08 > 0:08:11by sending out pulses of electromagnetic radiation
0:08:11 > 0:08:13and collecting their reflections
0:08:13 > 0:08:16when they bounce off objects in the sky.
0:08:16 > 0:08:21Its range varies, but modern systems can reach around 100 miles.
0:08:25 > 0:08:29The range is limited by the power that this radar can put out.
0:08:29 > 0:08:33The electromagnetic pulse has got to travel all the way out there,
0:08:33 > 0:08:36bounce off the aircraft and travel all the way back.
0:08:36 > 0:08:38So therefore the power, when it gets back,
0:08:38 > 0:08:40is going to be very low indeed.
0:08:40 > 0:08:45The other main problem is that the radar is not terribly accurate.
0:08:45 > 0:08:47And it certainly can't identify the target either.
0:08:47 > 0:08:51So all it can say is, "There's an aircraft there,
0:08:51 > 0:08:53"at this range, in that position."
0:08:54 > 0:08:57To extend their surveillance of the skies,
0:08:57 > 0:09:01air traffic controllers rely on a more sophisticated type of radar
0:09:01 > 0:09:02called secondary radar.
0:09:05 > 0:09:09The top rectangular part is the secondary radar.
0:09:09 > 0:09:12What that will do is it's an interrogator.
0:09:13 > 0:09:17Secondary radar has a far longer range than primary radar
0:09:17 > 0:09:20because it doesn't rely on detecting reflections.
0:09:22 > 0:09:25Instead, it sends a signal out to the aircraft,
0:09:25 > 0:09:28which interrogates a piece of equipment on board
0:09:28 > 0:09:29called a transponder.
0:09:29 > 0:09:33And it's the transponder that sends a new signal back,
0:09:33 > 0:09:37identifying the aircraft, its height and course.
0:09:39 > 0:09:41Controllers controlling the flights on long range,
0:09:41 > 0:09:45they will nearly always rely totally on the secondary radar system
0:09:45 > 0:09:48because the primary radars are just not providing the information.
0:09:56 > 0:09:5938 minutes into the flight, air traffic controllers in Malaysia
0:09:59 > 0:10:03could clearly see MH370 on their secondary radar.
0:10:05 > 0:10:08As the aircraft neared the limit of Malaysian airspace,
0:10:08 > 0:10:12the crew were told to contact air traffic controllers in Vietnam.
0:10:13 > 0:10:16These are the last words from the cockpit:
0:10:26 > 0:10:29At 21 minutes and four seconds past one,
0:10:29 > 0:10:33Malaysian air traffic controllers saw the plane passing over
0:10:33 > 0:10:35waypoint Igari on their secondary radar.
0:10:35 > 0:10:37Nine seconds later...
0:10:39 > 0:10:42..the radar screens went black.
0:10:49 > 0:10:51The aircraft's transponder,
0:10:51 > 0:10:54crucial to its visibility on secondary radar,
0:10:54 > 0:10:55had stopped working.
0:10:57 > 0:10:59The plane had vanished.
0:11:03 > 0:11:07And the mystery that's touched millions of lives began.
0:11:14 > 0:11:17What happened next is one of the key unanswered questions.
0:11:19 > 0:11:22The crew made no radio contact with air traffic controllers
0:11:22 > 0:11:26in Vietnam and the plane never re-appeared on secondary radar.
0:11:27 > 0:11:3017 minutes elapsed before the Vietnamese controllers
0:11:30 > 0:11:32contacted Malaysia.
0:11:36 > 0:11:40What does seem very odd is that,
0:11:40 > 0:11:46after the aeroplane was told to contact Ho Chi Minh
0:11:46 > 0:11:52air traffic control, it was a full 17 minutes between then and
0:11:52 > 0:11:57Ho Chi Minh phoning back to Malaysia to say, "Where is Malaysia 370?
0:11:57 > 0:11:59"He's not speaking to me."
0:11:59 > 0:12:0317 minutes is an incredible length of time.
0:12:03 > 0:12:07Within a couple of minutes you would normally be looking to see
0:12:07 > 0:12:09what's happened here.
0:12:11 > 0:12:15Now the Vietnamese and Malaysian air traffic controllers began
0:12:15 > 0:12:18looking for the aircraft.
0:12:18 > 0:12:22Professor Stupples can reveal why they were struggling to find it.
0:12:24 > 0:12:27At this point, here, that's the point
0:12:27 > 0:12:31where it disappeared from the secondary radars.
0:12:31 > 0:12:35What I've done here is put an overlay of the secondary surveillance radars
0:12:35 > 0:12:39and can you see here, there's almost a complete coverage
0:12:39 > 0:12:43and so therefore, so long as the transponder is working correctly,
0:12:43 > 0:12:48the whole of this route is covered by the secondary radar.
0:12:48 > 0:12:52But once MH370 was lost from secondary radar,
0:12:52 > 0:12:57the air traffic controllers had no other surveillance to fall back on.
0:12:58 > 0:13:03After removing the overlay for the secondary surveillance radar,
0:13:03 > 0:13:08we're now left with the coverage of the primary surveillance radar.
0:13:08 > 0:13:12Only about 50% to 60% of the journey so far is covered
0:13:12 > 0:13:15by the primary surveillance radar.
0:13:15 > 0:13:19The point at issue also is, at this point, where the transponder
0:13:19 > 0:13:22stopped working, you can see from this diagram,
0:13:22 > 0:13:25it is completely outside the range of any of
0:13:25 > 0:13:27the primary surveillance radars.
0:13:27 > 0:13:30Essentially, this aircraft has now become invisible.
0:13:33 > 0:13:37MH370 was lost in a primary radar blind spot.
0:13:46 > 0:13:48Such blind spots are common,
0:13:48 > 0:13:52because it's estimated only 10% of the globe is covered by radar.
0:13:54 > 0:13:59Aircraft often fly across oceans and remote regions beyond its reach.
0:14:03 > 0:14:07In one of the busiest radar blind spots, Hudson Bay in Canada,
0:14:07 > 0:14:11air traffic controllers are solving the problem with a revolutionary,
0:14:11 > 0:14:13new kind of surveillance.
0:14:15 > 0:14:20Between 100 and 300 aircraft are flying over Hudson Bay every day.
0:14:21 > 0:14:24Most of them are aircraft coming from Europe,
0:14:24 > 0:14:27going to the western coast of the United States.
0:14:27 > 0:14:29The rest of them are coming from North America,
0:14:29 > 0:14:31going to Asia over the North Pole.
0:14:31 > 0:14:34That's quite a busy airspace.
0:14:34 > 0:14:38There is no radar coverage of Hudson Bay.
0:14:38 > 0:14:41When air traffic controllers had no other means to track planes,
0:14:41 > 0:14:46they had to rely on pilots to stay in touch.
0:14:46 > 0:14:51The orange one is a flight that is not at the moment captured by radar.
0:14:51 > 0:14:56So this one at the moment we are not 100% sure he is there.
0:14:57 > 0:15:00This plane's position is an approximation,
0:15:00 > 0:15:04derived from its flight plan and regular updates from the aircraft.
0:15:06 > 0:15:10When you have no radar, in non-radar environment, when you have no way
0:15:10 > 0:15:14to see planes, actually. You need to rely on estimates from the pilots.
0:15:18 > 0:15:20Now, a new technology called
0:15:20 > 0:15:25Automatic Dependant Surveillance Broadcast or ADS-B is taking
0:15:25 > 0:15:30the guesswork out of tracking flights in radar blind spots.
0:15:30 > 0:15:36Aircraft fitted with ADS-B take their position from a GPS satellite
0:15:36 > 0:15:40and broadcast it automatically to a ground station.
0:15:40 > 0:15:45Unlike radar stations, these ADS-B receivers are robust enough to
0:15:45 > 0:15:49be sited in the remote regions where blind spots exist.
0:15:52 > 0:15:56We have currently one aircraft under ADS-B coverage at the moment,
0:15:56 > 0:16:01this is a United flight from Chicago going to Beijing.
0:16:01 > 0:16:07The aircraft in white is using ADS-B to broadcast its exact GPS location
0:16:07 > 0:16:09automatically once a second.
0:16:12 > 0:16:14We see the aircraft, we know its there.
0:16:14 > 0:16:17We know exactly where the aircraft is at all times.
0:16:18 > 0:16:24In the future, ADS-B ground stations will be supplemented by satellites.
0:16:24 > 0:16:27So planes will be tracked over remote land regions
0:16:27 > 0:16:29or the middle of oceans.
0:16:29 > 0:16:32Surveillance blind spots will be a thing of the past.
0:16:39 > 0:16:43MH370 was broadcasting its position by ADS-B.
0:16:43 > 0:16:46And this website was tracking it.
0:16:46 > 0:16:51But the system isn't currently used in Malaysia and Vietnam.
0:16:51 > 0:16:55And even if it was, it wouldn't have helped the air traffic controllers -
0:16:55 > 0:16:59because the technology still relies on the transponder.
0:16:59 > 0:17:04When that stopped working, this new tracking system was useless.
0:17:11 > 0:17:15The disappearance of MH370 triggered intense speculation
0:17:15 > 0:17:18about the fate of the 239 people on board.
0:17:22 > 0:17:25The families of the missing needed answers.
0:17:28 > 0:17:31Tony Cable is a veteran air crash investigator
0:17:31 > 0:17:35who worked on the Lockerbie bombing and the Concorde disaster.
0:17:37 > 0:17:42With any investigation, you have to go with the evidence you've got.
0:17:42 > 0:17:45And in the case of MH370, it's pretty slim.
0:17:48 > 0:17:51It's useful to think about the possible scenarios
0:17:51 > 0:17:54based on the available evidence.
0:17:54 > 0:17:58So, what could explain the aircraft's sudden disappearance
0:17:58 > 0:18:03from secondary radar and the radio silence?
0:18:03 > 0:18:05Any aircraft that suddenly disappears,
0:18:05 > 0:18:09inevitably, you start talking about the possibilities.
0:18:09 > 0:18:13And I guess they range from structural failure, terrorist action,
0:18:13 > 0:18:18some other massive technical fault that could cause a loss of control.
0:18:22 > 0:18:25A key piece of evidence for investigators
0:18:25 > 0:18:28is what MH370 was carrying on board.
0:18:31 > 0:18:34This is the MH370 cargo manifest here,
0:18:34 > 0:18:39which lists out the various packages and particularly,
0:18:39 > 0:18:43anything that is categorised as dangerous cargo.
0:18:43 > 0:18:47There is quite an interesting item here of
0:18:47 > 0:18:49lithium ion batteries.
0:18:49 > 0:18:51"Must be handled with care."
0:18:51 > 0:18:57And a "flammability hazard exists if the package is damaged."
0:19:00 > 0:19:05Lithium batteries can be found in laptops and mobile phones.
0:19:05 > 0:19:10All batteries are flammable, but lithium is one of the most volatile.
0:19:12 > 0:19:17MH370 was carrying 200kg of lithium batteries.
0:19:17 > 0:19:21There are tight regulations around how they are transported
0:19:21 > 0:19:25because they are thought to have caused fires on aircraft before.
0:19:26 > 0:19:33There was a Boeing 747 aircraft crash near Dubai in 2010.
0:19:33 > 0:19:38The investigation concluded that there was strong evidence that
0:19:38 > 0:19:42lithium ion batteries had started the fire.
0:19:46 > 0:19:49A fire in the cargo hold could affect the rest of the aircraft.
0:19:52 > 0:19:58You can get structural damage, damage to systems, a lot of smoke,
0:19:58 > 0:20:03severe visibility problems and also toxic gases.
0:20:04 > 0:20:08If there is a serious fire, case history suggests,
0:20:08 > 0:20:11unless a plane can land quickly, it is likely to crash.
0:20:13 > 0:20:16If there had been a fire on this aircraft
0:20:16 > 0:20:21then the tendency would be to look for the aircraft, the wreckage,
0:20:21 > 0:20:23at the point where you last had contact with it.
0:20:24 > 0:20:27And projecting the flight path a little further forward.
0:20:30 > 0:20:34Four hours after MH370 disappeared, a search was triggered
0:20:34 > 0:20:38in the China Sea, close to where the aircraft
0:20:38 > 0:20:41was last seen on secondary radar - to no avail.
0:20:43 > 0:20:48We have not found any wreckage, no wreckage whatsoever.
0:20:55 > 0:20:58Now the mystery of what happened to MH370 deepened.
0:21:00 > 0:21:046,500 miles away in London, one scientist was starting to think
0:21:04 > 0:21:08the aircraft could not have crashed in the South China Sea.
0:21:13 > 0:21:16'BBC news at 11 o'clock...'
0:21:16 > 0:21:19I heard the news about the loss of the aircraft, I think
0:21:19 > 0:21:21it was on the 11 o'clock BBC News.
0:21:21 > 0:21:24'..the search for a missing airliner with almost 240 people on board...'
0:21:24 > 0:21:27At that point I thought,
0:21:27 > 0:21:31it's probably got Inmarsat equipment on.
0:21:31 > 0:21:33'..no distress signal...'
0:21:33 > 0:21:35And that maybe we had some data
0:21:35 > 0:21:39that was of interest to the investigators.
0:21:42 > 0:21:46Alan Schuster-Bruce is a scientist with Inmarsat who provided
0:21:46 > 0:21:49satellite communications for MH370.
0:21:52 > 0:21:55By looking at the log of the plane's communications,
0:21:55 > 0:21:59Alan could see new information about the flight.
0:22:00 > 0:22:03What one sees in the data just before take-off,
0:22:03 > 0:22:05so when the aircraft is on the stand at Kuala Lumpur,
0:22:05 > 0:22:09there's a flurry of activity, the aircraft takes off, there is
0:22:09 > 0:22:14a flurry of activity and then everything stops.
0:22:16 > 0:22:22The last communication from MH370, like all its satellite traffic,
0:22:22 > 0:22:25was logged at a ground station in Perth, Australia.
0:22:28 > 0:22:33After 60 minutes of inactivity, the station sends a signal
0:22:33 > 0:22:37to the aircraft which says, are you still there?
0:22:37 > 0:22:40Then the aircraft just replies yes.
0:22:40 > 0:22:44These are what we call the handshakes or pings.
0:22:46 > 0:22:49Now Alan made a baffling discovery.
0:22:49 > 0:22:53The data log showed there were seven of these electronic handshakes
0:22:53 > 0:22:58between the ground station and MH370, each about one hour apart.
0:22:59 > 0:23:04They all occurred after the plane had vanished.
0:23:06 > 0:23:11Our data indicated that the aircraft had flown on for many, many hours
0:23:11 > 0:23:15beyond the last known contact with the aircraft, which clearly
0:23:15 > 0:23:19meant the aircraft was unlikely to be in the South China Sea.
0:23:20 > 0:23:22The story the data was revealing was
0:23:22 > 0:23:25so bizarre it seemed it couldn't be true.
0:23:28 > 0:23:32One of the concerns we had was in fact this could be just
0:23:32 > 0:23:36one big hoax someone had played on Inmarsat, that the aircraft
0:23:36 > 0:23:41went down and someone at the same time pretended to be that aircraft.
0:23:43 > 0:23:45But the data checked out.
0:23:46 > 0:23:50The aircraft had flown on for nearly seven more hours.
0:23:52 > 0:23:57And it could be thousands of miles away from the South China Sea.
0:24:01 > 0:24:05At that point it was quite clear something strange had happened
0:24:05 > 0:24:09because the plane had flown on for all those many hours.
0:24:10 > 0:24:14Where had the aircraft flown for all that time?
0:24:14 > 0:24:18MH370 was connected to a communications satellite
0:24:18 > 0:24:20called 3F1.
0:24:25 > 0:24:27This is the footprint of its beam.
0:24:28 > 0:24:32There is no direct way of identifying where MH370 was
0:24:32 > 0:24:36within the beam when the seven electronic handshakes occurred,
0:24:36 > 0:24:39but deep in the architecture of the system,
0:24:39 > 0:24:43a feature had been added that might offer a clue.
0:24:46 > 0:24:49'French investigators say they have recovered 400 pieces of debris
0:24:49 > 0:24:52'from Air France Flight 447.
0:24:52 > 0:24:55'They say the wreckage comes from all areas of the plane.'
0:24:55 > 0:25:00In 2009, Alan helped with the investigation into the disappearance
0:25:00 > 0:25:02of Air France 447.
0:25:04 > 0:25:07They had a couple of brainstorming sessions at Inmarsat.
0:25:07 > 0:25:13One of the things we did work out is that we could take some
0:25:13 > 0:25:17additional measurements in the stations and that would let us
0:25:17 > 0:25:23get a determination of the distance from the satellite to the aircraft
0:25:23 > 0:25:27and therefore that would give a one-dimensional position fix.
0:25:29 > 0:25:34So, after the Air France disaster, Alan decided to keep timing data
0:25:34 > 0:25:38in the electronic handshakes that might help track an aircraft.
0:25:41 > 0:25:43I was thinking we might need it one day.
0:25:43 > 0:25:48It might be useful, might not be useful, but I had no idea
0:25:48 > 0:25:53it would essentially be the only evidence in town.
0:25:55 > 0:26:00To try to find MH370, Alan now began analysing the type of data
0:26:00 > 0:26:03stored in electronic handshakes.
0:26:06 > 0:26:11He knew the position of the 3F1 satellite above the Indian Ocean.
0:26:11 > 0:26:13Using the timing data in each handshake,
0:26:13 > 0:26:16he could work out how long it took for the signal
0:26:16 > 0:26:20to travel between the satellite and the aircraft.
0:26:20 > 0:26:23From that he could work out the distance between the satellite
0:26:23 > 0:26:26and the aircraft when each handshake occurred.
0:26:27 > 0:26:29Plotting those distances created
0:26:29 > 0:26:33seven circles on the surface of the Earth around the satellite
0:26:33 > 0:26:36which the plane must have crossed as it flew.
0:26:40 > 0:26:43The last circle came at 8.19 in the morning.
0:26:45 > 0:26:49The aircraft did not reply to the satellite 57 minutes later.
0:26:51 > 0:26:55We obviously knew that that was most likely indicative
0:26:55 > 0:26:58of the time the aircraft was lost.
0:27:01 > 0:27:02Later that week,
0:27:02 > 0:27:06Inmarsat sent their analysis to the Malaysia authorities.
0:27:06 > 0:27:09The search carried on in the South China Sea.
0:27:11 > 0:27:15Clearly, they've got all sorts of information coming in.
0:27:15 > 0:27:18They were also probably sent information that the plane was
0:27:18 > 0:27:20in the Pacific by other people,
0:27:20 > 0:27:22so I'm sure it's very difficult for them.
0:27:25 > 0:27:29Alan and the team began to think their methods might yield
0:27:29 > 0:27:30the ultimate clue.
0:27:32 > 0:27:37We suddenly realised, if you knew the initial position of the aircraft,
0:27:37 > 0:27:42together with the likely speed of the aeroplane, there was
0:27:42 > 0:27:46a good chance that maybe one could get the track of the aircraft.
0:27:47 > 0:27:51A telephone call was arranged with Malaysia Airlines to get
0:27:51 > 0:27:52the information they needed.
0:27:54 > 0:27:55They did provide that information.
0:27:55 > 0:27:58But certainly there was a lot of reluctance
0:27:58 > 0:28:02because the last known position was based on radar data
0:28:02 > 0:28:06and there was a lot of concern about the sensitivity of the radar data.
0:28:07 > 0:28:09Using this new information,
0:28:09 > 0:28:12Inmarsat could rule out areas of the final circle
0:28:12 > 0:28:16the aircraft could never have reached with the fuel it had.
0:28:17 > 0:28:20MH370 must have ended its flight
0:28:20 > 0:28:23crossing one of these two arcs.
0:28:23 > 0:28:26We had two possible scenarios.
0:28:26 > 0:28:30It had either turned left and gone south or turned right and gone north.
0:28:30 > 0:28:32We didn't know which one.
0:28:35 > 0:28:38After several days of no traction for the new evidence,
0:28:38 > 0:28:42suddenly the story broke from an unlikely source.
0:28:42 > 0:28:47Based on new information, an additional search area may be opened in the Indian Ocean.
0:28:47 > 0:28:51It seemed the Americans hoped to push the Malaysians to act.
0:28:53 > 0:28:56It was a bit strange that it was the White House announcing it
0:28:56 > 0:28:59as opposed to the Malaysian government which is what one
0:28:59 > 0:29:02would have expected, that it would come from the Malaysian government.
0:29:02 > 0:29:07I think there was a certain amount of relief that finally the secret
0:29:07 > 0:29:11that we were holding was now out in the public domain.
0:29:13 > 0:29:16For those trying to find the aircraft,
0:29:16 > 0:29:20the search had been narrowed, but it was still vast.
0:29:20 > 0:29:22More than two million square miles
0:29:22 > 0:29:26stretching from Kazakhstan in the north to the southern Indian Ocean.
0:29:31 > 0:29:35The mystery of MH370 had taken a staggering twist.
0:29:36 > 0:29:41The sensitive information Inmarsat had used to help work out the arcs
0:29:41 > 0:29:45turned out to be top-secret military radar data that
0:29:45 > 0:29:50showed MH370 made an inexplicable turn west, off its course
0:29:50 > 0:29:54to Beijing, after it disappeared.
0:29:55 > 0:29:58It then flew across the Malaysian Peninsular...
0:30:01 > 0:30:05..before making another turn, this time north-west.
0:30:05 > 0:30:11It was last recorded near the Andaman Islands at 2.22am.
0:30:11 > 0:30:16This new radar data raised a sinister possibility.
0:30:16 > 0:30:19These movements are consistent
0:30:19 > 0:30:25with deliberate action by someone on the plane.
0:30:28 > 0:30:30From the available evidence,
0:30:30 > 0:30:34hijacking is clearly one plausible possibility.
0:30:35 > 0:30:39The fact that MH370 had deviated from its course after it had
0:30:39 > 0:30:43become invisible to secondary radar suggested the aircraft's
0:30:43 > 0:30:47transponder could have been turned off deliberately.
0:30:48 > 0:30:51It's actually such an important part of your navigational equipment
0:30:51 > 0:30:54on modern aircraft that you wouldn't want to turn it off.
0:30:55 > 0:30:58But those with a criminal intent might.
0:30:59 > 0:31:03It's fairly common that the hijackers know enough
0:31:03 > 0:31:07about aircraft that they will require the transponder
0:31:07 > 0:31:10either to be switched off or left on its original code.
0:31:13 > 0:31:16Investigators began a trawl for suspects.
0:31:16 > 0:31:19The passenger list was a crucial starting point.
0:31:19 > 0:31:22Police quickly focused on two Iranians who were
0:31:22 > 0:31:25travelling on forged passports, but they were ruled out.
0:31:27 > 0:31:30The pilots themselves came under intense scrutiny,
0:31:30 > 0:31:34but no evidence of a terrorist link has been found so far.
0:31:36 > 0:31:40That, of course, does not demonstrate that there was not
0:31:40 > 0:31:46a hijacking by crew or passengers - that is a possibility.
0:31:46 > 0:31:49It's just that the things against hijacking in this case is
0:31:49 > 0:31:52that nobody has claimed responsibility, which is
0:31:52 > 0:31:54pretty unusual, I think, for a terrorist act.
0:32:00 > 0:32:04More than a week after MH370 vanished, no sign
0:32:04 > 0:32:10of the aircraft had been found, despite the efforts of 26 countries.
0:32:12 > 0:32:15That gave many of the families of those on board
0:32:15 > 0:32:17hope that they would be found alive.
0:32:25 > 0:32:27At Inmarsat in London,
0:32:27 > 0:32:30a new attempt was being made to help target the search.
0:32:32 > 0:32:36They knew the plane had ended up crossing one of two arcs.
0:32:38 > 0:32:41Chris Ashton was trying to work out
0:32:41 > 0:32:45whether the aircraft had gone north or south.
0:32:45 > 0:32:49Of course, the big question is which route was taken?
0:32:50 > 0:32:54There was one more avenue to explore in the electronic handshakes,
0:32:54 > 0:32:56a second piece of data -
0:32:56 > 0:32:59the frequency at which the signal from the aircraft
0:32:59 > 0:33:01arrived at the ground station.
0:33:01 > 0:33:02We had a northern
0:33:02 > 0:33:04and a southern route that were
0:33:04 > 0:33:06so very different, so very far apart,
0:33:06 > 0:33:08the frequency information at that stage
0:33:08 > 0:33:10was something that was probably going to be good enough
0:33:10 > 0:33:12to discriminate between those two routes.
0:33:16 > 0:33:19The satellite MH370 was in contact with
0:33:19 > 0:33:21doesn't stay still in the sky.
0:33:23 > 0:33:26The satellite moves north and south over the equator...
0:33:28 > 0:33:30..and because the plane is also moving, there is
0:33:30 > 0:33:35a variation in the frequency of the signals between them.
0:33:35 > 0:33:38Since that variation, known as the Doppler effect,
0:33:38 > 0:33:41is predictable, it can be used to work out the direction
0:33:41 > 0:33:43the plane is travelling in.
0:33:58 > 0:34:01The calculations were incredibly complex
0:34:01 > 0:34:04and there was no guarantee of success.
0:34:06 > 0:34:09We'd attempted this calculation two or three times and abandoned it,
0:34:09 > 0:34:14as we were working at it for a long time and not getting a good match
0:34:14 > 0:34:17between the measured data and the predicted data.
0:34:21 > 0:34:23But then came the break.
0:34:27 > 0:34:31We'd been working on the Doppler analysis all day long,
0:34:31 > 0:34:34the end of a week of investigating and collecting data.
0:34:35 > 0:34:39Quite late on the Friday night, about eight o'clock in the evening,
0:34:39 > 0:34:43suddenly the graphs matched, the data worked, the calculation was solved.
0:34:45 > 0:34:52Chris had eliminated a hemisphere, but he didn't yet know which.
0:34:52 > 0:34:57That was quite a nice feeling, that we'd got the calculation to work,
0:34:57 > 0:35:00and then I checked to see which of the flight paths it was
0:35:00 > 0:35:03and we then identified it was, in fact, the southern route.
0:35:08 > 0:35:12That meant flight MH370 must have flown south.
0:35:14 > 0:35:17Then, there's, of course, the realisation that this is the...
0:35:17 > 0:35:20This is not good news for the people on the plane.
0:35:20 > 0:35:23This isn't the aircraft is hijacked and is flying up to Kazakhstan,
0:35:23 > 0:35:28landing safely and everybody's in a hangar, this was the specific one
0:35:28 > 0:35:31where it flies south into the middle of the Indian Ocean.
0:35:31 > 0:35:36You feel the depth of this, the severity of it.
0:35:36 > 0:35:40It means very little chance for the people on the aircraft.
0:35:40 > 0:35:45There was no land there. There's nothing at the end of the route
0:35:45 > 0:35:47and so the elation didn't last for very long
0:35:47 > 0:35:49when you realised what this meant.
0:35:51 > 0:35:55Chris's evidence was sent to the Malaysian authorities.
0:35:56 > 0:36:01According to this new data,
0:36:01 > 0:36:06Flight MH370
0:36:06 > 0:36:11ended in the southern Indian Ocean.
0:36:15 > 0:36:19The fact that we'd done a calculation that indicated
0:36:19 > 0:36:20a lot of people had died
0:36:20 > 0:36:23and was being used by the Malaysian government to inform
0:36:23 > 0:36:28the next of kin that they believed that their relatives had died
0:36:28 > 0:36:30was quite, um, humbling, let's say.
0:36:38 > 0:36:44Science had broken open the mystery of what had happened to MH370,
0:36:44 > 0:36:46generating evidence where none existed.
0:36:50 > 0:36:54From Kuala Lumpur, the plane had been tracked by secondary radar
0:36:54 > 0:36:56until it disappeared here.
0:36:59 > 0:37:02Then it had been tracked by military primary radar to here.
0:37:05 > 0:37:08Then, in the absence of other surveillance,
0:37:08 > 0:37:12Inmarsat's analysis had shown the plane must have turned south
0:37:12 > 0:37:16crossing each arc as it flew on for six hours.
0:37:18 > 0:37:23From now on, locating the crash site becomes a matter of prediction,
0:37:23 > 0:37:25probability and possibility.
0:37:29 > 0:37:33What might explain the drastic course change south
0:37:33 > 0:37:35and the long flight over the ocean?
0:37:45 > 0:37:49The veteran crash investigator Tony Cable believes
0:37:49 > 0:37:52an earlier air disaster might help explain the final southward turn.
0:37:56 > 0:38:01In 2005, the crew of a Helios Airline's Boeing 737 failed to
0:38:01 > 0:38:06make radio contact with the ground, just like MH370.
0:38:08 > 0:38:12The aircraft was intercepted by a couple of F-16s
0:38:12 > 0:38:17and they flew alongside and saw the captain's seat empty, the co-pilot
0:38:17 > 0:38:23slumped over the controls and oxygen masks hanging down in the cabin.
0:38:25 > 0:38:29There was a fault with the aircraft's pressurisation system,
0:38:29 > 0:38:31but the crew hadn't realised.
0:38:32 > 0:38:37There is a quantity called "time of useful consciousness"
0:38:37 > 0:38:41after a depressurisation, and at 35,000 feet,
0:38:41 > 0:38:46the average is something like 30 to 60 seconds.
0:38:46 > 0:38:50The pilots passed out from lack of oxygen,
0:38:50 > 0:38:54but the aircraft kept flying on autopilot.
0:38:54 > 0:38:57What might explain what happened to MH370
0:38:57 > 0:39:00is what the fighter planes saw next.
0:39:01 > 0:39:05They saw one of the cabin attendants enter the flight deck
0:39:05 > 0:39:08and sit in the captain's seat.
0:39:08 > 0:39:14Now, he presumably had a cabin attendant oxygen set
0:39:14 > 0:39:18which will probably last quite a long time
0:39:18 > 0:39:22and was presumably attempting to control the aircraft.
0:39:24 > 0:39:28If the pilots of MH370 had become incapacitated,
0:39:28 > 0:39:32might somebody else have tried to fly the aircraft?
0:39:32 > 0:39:36If the plane was on autopilot, making a controlled turn
0:39:36 > 0:39:39or a series of turns, is something anyone could have done.
0:39:41 > 0:39:44We can command the autopilot directly ourselves
0:39:44 > 0:39:47through the mode control panel up here.
0:39:47 > 0:39:52So we can do that quite easily by selecting a new heading
0:39:52 > 0:39:53through this knob here.
0:39:54 > 0:39:58So now the aircraft is banking to the left and we're gradually... You see
0:39:58 > 0:40:01outside, we are banking to the left and turn onto that heading.
0:40:01 > 0:40:04So could somebody other than one of the pilots
0:40:04 > 0:40:07have turned the aircraft off its course?
0:40:09 > 0:40:13The kind of thing that happened on the Helios 737 might be
0:40:13 > 0:40:16a possibility for this aircraft.
0:40:16 > 0:40:20And if there was somebody conscious for longer than the others,
0:40:20 > 0:40:25possibly could explain the track corrections
0:40:25 > 0:40:27before they also were incapacitated.
0:40:28 > 0:40:32Even if everybody on board was unconscious, the autopilot
0:40:32 > 0:40:35could have kept the aircraft flying until it ran out of fuel.
0:40:37 > 0:40:43But how and why MH370 came to be so far off course heading south
0:40:43 > 0:40:46is still to be established for certain.
0:40:46 > 0:40:49There are several possible scenarios for this accident.
0:40:49 > 0:40:54I don't have any feeling about which is the more likely.
0:40:54 > 0:40:58As an investigator, you can only go on the evidence that is there.
0:41:03 > 0:41:08For those touched by this disaster, the best hope of finding answers
0:41:08 > 0:41:12lies somewhere at the bottom of the Indian Ocean.
0:41:13 > 0:41:18Piecing together what really happened depends on finding
0:41:18 > 0:41:21one piece of equipment the aircraft was carrying.
0:41:25 > 0:41:28This is what they call a black box,
0:41:28 > 0:41:31but I've never seen one that's actually black.
0:41:31 > 0:41:34This makes it more visible in wreckage
0:41:34 > 0:41:37and indeed it's got reflective tape on it,
0:41:37 > 0:41:40so that if it's at night, a torch will light it up
0:41:40 > 0:41:45or if it's under the water, a diver's light will make it more visible.
0:41:45 > 0:41:49The black box is a data recorder which continually stores
0:41:49 > 0:41:53a record of how the aircraft is performing.
0:41:53 > 0:41:56From that information, you can recreate in detail
0:41:56 > 0:41:58what happened to the flight.
0:42:00 > 0:42:04You are looking at an animation of the data taken from a recorder.
0:42:04 > 0:42:08You've got the actual way the aircraft is moving through space,
0:42:08 > 0:42:12and on the left is a representation of the cockpit instruments -
0:42:12 > 0:42:14what the pilot would be seeing.
0:42:14 > 0:42:19The data in the black box is crucial to finding out what happened...
0:42:21 > 0:42:22..if you can find it.
0:42:24 > 0:42:29If it's in water, the underwater locator beacon,
0:42:29 > 0:42:33which emits a ping every second or so can be homed in on.
0:42:33 > 0:42:37But the batteries that power the locator beacon
0:42:37 > 0:42:40only last for about 30 days.
0:42:44 > 0:42:46In the southern Indian Ocean,
0:42:46 > 0:42:50in an area dubbed as close to nowhere as it's possible to be,
0:42:50 > 0:42:54the race to find the black box was on.
0:42:56 > 0:42:59Aircraft and ships from eight nations
0:42:59 > 0:43:02were scouring 620,000 square miles of ocean.
0:43:05 > 0:43:08Could anything be done to help target the search?
0:43:13 > 0:43:18Back in London, Inmarsat had been scrutinising probable flight paths
0:43:18 > 0:43:19MH370 could have taken.
0:43:21 > 0:43:24And what they had discovered was astonishing.
0:43:25 > 0:43:29By modelling a flight with a constant speed
0:43:29 > 0:43:31and a constant heading consistent with
0:43:31 > 0:43:34the plane being flown by autopilot,
0:43:34 > 0:43:39they had found one flight path that lined up with all their data.
0:43:41 > 0:43:44We can identify a path that matches exactly
0:43:44 > 0:43:47with all those frequency measurements
0:43:47 > 0:43:50and with the timing measurements and lands on the final arc at a particular location,
0:43:50 > 0:43:54which then gives us a kind of hotspot area on the final arc
0:43:54 > 0:43:57where we believe the most likely area is.
0:44:01 > 0:44:05But as the battery life of the black box ran down,
0:44:05 > 0:44:08events in the Indian Ocean were unfolding fast.
0:44:16 > 0:44:19At the forefront of the search was the Ocean Shield,
0:44:19 > 0:44:23a 6,500 tonne Australian Navy support vessel,
0:44:23 > 0:44:27carrying an elite team of deep-ocean salvage experts.
0:44:29 > 0:44:34We left port on approximately day 23 of the pinger,
0:44:34 > 0:44:37the battery life on the pinger -
0:44:37 > 0:44:40this countdown clock, so to speak.
0:44:40 > 0:44:4230 was the magic number.
0:44:43 > 0:44:48Suddenly, a new lead emerged, and Ocean Shield responded.
0:44:52 > 0:44:54A British vessel seemed to have found a clue
0:44:54 > 0:44:56to the location of the black box.
0:44:58 > 0:45:05HMS Echo believed they had detected a 37.5 kilohertz pulse in the water.
0:45:05 > 0:45:10So we headed to that area and came up with a search plan.
0:45:11 > 0:45:16Now, Ocean Shield joined the hunt for signals from the black box,
0:45:16 > 0:45:20working its way south-east, away from HMS Echo.
0:45:26 > 0:45:29To try to detect the elusive underwater pings,
0:45:29 > 0:45:33the team used a device they call the towed pinger locator.
0:45:36 > 0:45:39The towed pinger locator looks much like a bat wing
0:45:39 > 0:45:41and designed that way on purpose
0:45:41 > 0:45:44so when it's pulled from its tow point here,
0:45:44 > 0:45:47it's flying pretty smoothly through the water.
0:45:47 > 0:45:50The real meat of this is underneath it.
0:45:51 > 0:45:54What you see here is the electronics
0:45:54 > 0:45:57that is housed in a 6,000 metre pressure vessel.
0:45:57 > 0:45:59You can get down 6,000 metres,
0:45:59 > 0:46:03that's covering about 80% of the world's ocean depths.
0:46:03 > 0:46:07And what you see on the back here is the omnidirectional hydrophone.
0:46:07 > 0:46:09It's a microphone, a big microphone, hemispherical.
0:46:09 > 0:46:12It can see 180 degrees to each side and down.
0:46:12 > 0:46:17We're fishing for sound in this case. Patience is key throughout.
0:46:21 > 0:46:24Even if you can detect the sound of a black box pinger,
0:46:24 > 0:46:28locating its origin is a huge challenge,
0:46:28 > 0:46:32especially in an ocean four and a half kilometres deep.
0:46:34 > 0:46:39The pinger locator is lowered until it is a kilometre above the sea bed
0:46:39 > 0:46:42where it is towed as it listens with its hydrophone.
0:46:42 > 0:46:45PINGING
0:46:45 > 0:46:47At that depth, it avoids plankton
0:46:47 > 0:46:49and changing water temperatures above,
0:46:49 > 0:46:52which can affect the way the sound travels.
0:46:53 > 0:46:58And what's more, the sea bed itself can obscure the origin of any sound.
0:47:00 > 0:47:05Wreckage can deflect the sound path, the topography of the bottom.
0:47:05 > 0:47:10We are seeing a lot of steep hills, valleys, ridges,
0:47:10 > 0:47:14the sound will find a path of least resistance.
0:47:16 > 0:47:18As Ocean Shield worked its way
0:47:18 > 0:47:23along one of MH370's possible flight paths, there was bad news.
0:47:25 > 0:47:30During that survey leg, HMS Echo was able to deduce
0:47:30 > 0:47:35that the 37.5 kilohertz pings they were hearing were not valid.
0:47:38 > 0:47:40The trail had gone cold.
0:47:40 > 0:47:42We're running our line this way along the projected flight path.
0:47:42 > 0:47:44At that point, we regrouped
0:47:44 > 0:47:47and went back to our best known last position,
0:47:47 > 0:47:49being the eight minute arc.
0:47:49 > 0:47:52And our intention was to work our way south.
0:47:52 > 0:47:55South was determined to have a higher probability,
0:47:55 > 0:47:58a more probable flightpath.
0:47:58 > 0:48:01North-west side to the south-east.
0:48:01 > 0:48:04The search area referred to as the eight-minute arc
0:48:04 > 0:48:06is based on the final handshake
0:48:06 > 0:48:09between MH370 and the Inmarsat satellite.
0:48:09 > 0:48:12It came eight minutes after the previous handshake
0:48:12 > 0:48:15and contained new information.
0:48:16 > 0:48:20The data revealed the system on the plane was actually booting up,
0:48:20 > 0:48:23just as it would have done at the start of its flight.
0:48:23 > 0:48:29Why it would do this may hold a clue to the plane's final resting place.
0:48:30 > 0:48:32It's theorised to have been
0:48:32 > 0:48:35that the plane was going down, low on fuel.
0:48:37 > 0:48:39It did a roll.
0:48:39 > 0:48:42When the plane rolled, the fuel then...
0:48:42 > 0:48:46The engine was able to restart and part of the start-up sequence
0:48:46 > 0:48:50was initialised in this handshake with the Inmarsat.
0:48:54 > 0:48:56And it was an incomplete handshake.
0:48:59 > 0:49:03So we're working on the premise that perhaps this last handshake
0:49:03 > 0:49:07is where the plane was in its final stages.
0:49:21 > 0:49:25We were towing for 24 hours a day for days on end,
0:49:25 > 0:49:28for as long as the battery is going to last.
0:49:33 > 0:49:34The hunt for the black box
0:49:34 > 0:49:38was not so much like trying to find a needle in a haystack.
0:49:39 > 0:49:43Chris and his team hadn't even found the haystack.
0:49:44 > 0:49:46But what if they didn't have to search at all?
0:50:03 > 0:50:06In Ottawa in Canada there's a new technology
0:50:06 > 0:50:11that is bringing the black box into the 21st century.
0:50:11 > 0:50:15To see it, you need to visit a part of the plane
0:50:15 > 0:50:17passengers never normally go to.
0:50:25 > 0:50:29OK, so this is the E bay of the 767,
0:50:29 > 0:50:33and this is really the heart of the electronics for the aircraft.
0:50:33 > 0:50:36The data is fed from all the various sensors and equipment
0:50:36 > 0:50:38to the flight data recorder.
0:50:38 > 0:50:40What's unique about what we've done
0:50:40 > 0:50:44is we've added this unit here, which is the AFIRS.
0:50:44 > 0:50:48The Automated Flight Information Reporting System
0:50:48 > 0:50:50examines the data generated by the aircraft
0:50:50 > 0:50:52as it is being sent to the black box.
0:50:54 > 0:50:57The flight data recorder is a passive device.
0:50:57 > 0:50:59It takes the information and stores it,
0:50:59 > 0:51:01it doesn't actually look at it.
0:51:01 > 0:51:05This is actually analysing the data as it's going into the box.
0:51:05 > 0:51:08So it's actually reading the files. It's looking at them
0:51:08 > 0:51:10and seeing, "What's happening with this aeroplane?
0:51:10 > 0:51:12"Is everything working correctly?"
0:51:12 > 0:51:15And if it's not, it tells people, it lets them know.
0:51:17 > 0:51:20Aircraft fitted with this technology
0:51:20 > 0:51:23automatically stream black-box data to the ground
0:51:23 > 0:51:25if anything unusual happens.
0:51:27 > 0:51:30'Flight CFFNE flight stream activated.'
0:51:30 > 0:51:34Rather than having to recover the physical black box,
0:51:34 > 0:51:37now its data can build a picture of what happened
0:51:37 > 0:51:39before a flight even ends.
0:51:43 > 0:51:45It would seem to make a lot of sense
0:51:45 > 0:51:50to seriously consider real-time transmission of data.
0:51:50 > 0:51:52And in a case like MH370
0:51:52 > 0:51:55it may make it redundant to,
0:51:55 > 0:51:58from the accident investigation point of view,
0:51:58 > 0:52:00to actually go and find the wreckage,
0:52:00 > 0:52:03which is clearly going to be very, very difficult,
0:52:03 > 0:52:05very expensive, very time-consuming.
0:52:08 > 0:52:11Finding MH370 is a huge challenge.
0:52:11 > 0:52:14But advances in technology could mean
0:52:14 > 0:52:17that no aeroplane is ever lost again.
0:52:25 > 0:52:29In Montreal, aviation is being brought into the digital age.
0:52:31 > 0:52:34So here's the Piaggio Avanti P180 flight research aircraft
0:52:34 > 0:52:35we'll be flying today.
0:52:35 > 0:52:39It is the world's fastest civilian turboprop.
0:52:41 > 0:52:44Many of the technologies we are testing
0:52:44 > 0:52:45are surveillance technologies,
0:52:45 > 0:52:48because surveillance is the next wave of evolution
0:52:48 > 0:52:50of flight operations.
0:52:51 > 0:52:53John has been testing new ways
0:52:53 > 0:52:57of using Automatic Dependant Surveillance Broadcast -
0:52:57 > 0:53:01the technology that is revolutionising air-traffic control.
0:53:04 > 0:53:07They're up and indicating.
0:53:07 > 0:53:12John's aircraft doesn't just transmit ADS-B signals -
0:53:12 > 0:53:14crucially, it receives them too.
0:53:16 > 0:53:20With ADS-B in, I can see the traffic, I can see the direction they're moving in,
0:53:20 > 0:53:21and we can see if they're a threat,
0:53:21 > 0:53:24and we can see if they're climbing and descending as well.
0:53:24 > 0:53:29These two are potentially a threat. This one is 1,900 feet above us.
0:53:29 > 0:53:32With ADS-B in, we could actually, with that data,
0:53:32 > 0:53:35even recreate what that aeroplane is seeing from its cockpit.
0:53:40 > 0:53:42This live view of the flight John is making
0:53:42 > 0:53:45could be viewed by anyone, anywhere in the world,
0:53:45 > 0:53:49at any time, via ADS-B and the internet.
0:53:50 > 0:53:54When you go to an autonomous node, which is what this aircraft becomes,
0:53:54 > 0:53:57you open up enormous possibilities.
0:53:57 > 0:53:59You know where everybody is for the first time,
0:53:59 > 0:54:01no matter where they are in the world.
0:54:01 > 0:54:05Perhaps what's most surprising about this technology
0:54:05 > 0:54:08is that it isn't already a fact of life in the skies.
0:54:10 > 0:54:13You no longer have helpless recipients
0:54:13 > 0:54:14of radar energy flying around.
0:54:14 > 0:54:17You have contributors to a big information picture
0:54:17 > 0:54:19that everyone can use.
0:54:19 > 0:54:22Losing aircraft would become a thing of the past.
0:54:23 > 0:54:26Using advanced aviation technologies
0:54:26 > 0:54:28like live black-box streaming,
0:54:28 > 0:54:32and the total surveillance offered by ADS-B,
0:54:32 > 0:54:35could mean that losing an aircraft like MH370
0:54:35 > 0:54:37should never be possible again.
0:54:46 > 0:54:48But the promise of the future
0:54:48 > 0:54:51is a world away from the challenges of the present.
0:54:56 > 0:54:57Back in the Indian Ocean,
0:54:57 > 0:55:00on the day before the battery on the black-box pinger
0:55:00 > 0:55:02was predicted to die,
0:55:02 > 0:55:05Chris and his team thought they heard something.
0:55:07 > 0:55:11The towfish is at about 3,800 metres of depth
0:55:11 > 0:55:15and we're doing about two and a half knots.
0:55:17 > 0:55:19It started growing louder and louder.
0:55:23 > 0:55:25And we had a detection.
0:55:30 > 0:55:32Big moment.
0:55:32 > 0:55:34Are you sure that's what we heard?
0:55:34 > 0:55:39Are you sure that's what we're... Is it not us, you know?
0:55:39 > 0:55:43It was a elation and panic and self-doubt.
0:55:43 > 0:55:47Wonderment, to "let's get busy and find this thing,
0:55:47 > 0:55:48"let's track it down."
0:55:55 > 0:56:00They tracked the ping for two hours and 20 minutes before losing it.
0:56:01 > 0:56:04They detected another, 11 kilometres away.
0:56:06 > 0:56:08And then two more two days later.
0:56:11 > 0:56:15My thoughts were they were probably going to traverse down the final arc
0:56:15 > 0:56:17to go over our hotspot area
0:56:17 > 0:56:21but, of course, they found their ping detection very early on.
0:56:21 > 0:56:26Ocean Shield could not ignore the detections it had heard.
0:56:28 > 0:56:31The search entered a new phase.
0:56:32 > 0:56:34The decision was made that
0:56:34 > 0:56:36we had had enough detections
0:56:36 > 0:56:39and it was time to shift over to the AUV ops.
0:56:41 > 0:56:44The Autonomous Underwater Vehicle
0:56:44 > 0:56:47began searching the ocean floor for wreckage.
0:56:48 > 0:56:50It was a monumental task.
0:57:01 > 0:57:04The unexplained disappearance of MH370
0:57:04 > 0:57:08has left the families of those on board
0:57:08 > 0:57:10needing the kind of certainty
0:57:10 > 0:57:12that only finding the wreckage will bring.
0:57:17 > 0:57:19Ocean Shield spent two months
0:57:19 > 0:57:22searching 850 square kilometres of sea bed,
0:57:22 > 0:57:24inspired by the pings they heard.
0:57:25 > 0:57:29Ocean Shield had chased down leads as they emerged.
0:57:29 > 0:57:30But they turned up nothing.
0:57:36 > 0:57:39It was by no means an unrealistic location,
0:57:39 > 0:57:42but it was further to the north-east
0:57:42 > 0:57:45than our area of highest probability.
0:57:46 > 0:57:49Perhaps the best place to look for MH370
0:57:49 > 0:57:51was always further to the south.
0:57:51 > 0:57:53Inmarsat's hotspot on the final arc
0:57:53 > 0:57:58where their data says MH370 is most likely to have crashed
0:57:58 > 0:57:59is here...
0:58:03 > 0:58:06On Saturday 8th March 2014,
0:58:06 > 0:58:11MH370 took off on a routine flight to Beijing.
0:58:12 > 0:58:16Just under 40 minutes later it vanished.
0:58:18 > 0:58:22There have been many theories as to the fate of the plane
0:58:22 > 0:58:24and the global effort continues
0:58:24 > 0:58:26to try to solve the mystery
0:58:26 > 0:58:29and bring closure to the families of those who lost their lives.