by Ean Higgins
Australian search authorities urgently worked to establish what the Chinese had or had not found – would it be worth sending aircraft to drop sonar buoys urgently since they could get there fast while the signal was still there? Or would it be better to send the Australian or British vessel with the beacon locator equipment which were working over the northern part of the search area?
It was one case where international political sensitivities came into play, and had to be massaged. While to the external audience and particularly the international media, the three governments principally involved in the hunt for MH370 – Malaysia, China and Australia – maintained a united front, behind the scenes one of the key jobs of Houston and his deputy at the JACC, senior public servant Judith Zielke, was to smooth things over. In remarks she probably never thought would be reported, Zielke said there were ‘bumps along the way’ in this process.
Zielke made her remarks at the previously mentioned Institute of Public Administration seminar in Canberra in 2017, where AMSA’s Alan Lloyd had also spoken. It was not a big affair – just a relatively short session of an hour or so in which public servants were invited to hear how the JACC was set up, how it worked, and a bit about the search strategy. By that stage the Australian search had ended; that and the fact the event was relatively intimate saw the officials loosen up and make some at times revealing observations. Zielke told the IPA gathering, ‘The biggest thing that I have learnt from being involved in the search is actually the huge cultural differences between all the countries involved.’
She noted China had two thirds of the passengers as its nationals.
‘To be quite frank, as the outcry from the people increased when the aircraft wasn’t located, the greater China’s concern and engagement became,’ Zielke told the small gathering. ‘We were in effect dealing with China, as much as we were dealing with Malaysia, and continue to as well.’ It had been necessary for the Australians to respect ‘different work practices and approaches’ along with ‘gender issues or hierarchy issues’, Zielke said.
‘It’s important to remember that people are, culturally, the way they are, for a reason.’
It was an important revelation for the row that was to develop in future. As it came under pressure the ATSB said its search strategy decisions had always been non-political and based on objective scientific evidence; Zielke’s ‘quite frank’ admissions at the IPA seminar showed international political and cultural concerns did impinge, and were taken into account by the Australian search leaders.
On 6 April, Houston and his colleagues including Leavy called what journalists call a ‘presser’ to hold the line against headlines around the world that the Chinese had found MH370, while at the same time trying to avoid doing anything that might mean Beijing lost face.
‘This is an important, encouraging lead but one which I urge you to continue to treat carefully,’ Houston told journalists. ‘We are working in a very big ocean and within a very large search area.’
Houston said Echo would go to help the Chinese vessel, but ‘Ocean Shield will be delayed while she pursues an acoustic noise in her current location’.
So, journalists instantly began to wonder, what was this? What was the ‘acoustic noise in her current location’ that would delay Ocean Shield?
‘This only happened within the last 90 minutes,’ Leavy told the press pack. ‘We heard a report back from Ocean Shield, from the towed ping locator operators on board there, that they had picked up a detection. It is very, very early days.’
The next day, 7 April, Houston announced the best news in the hunt for MH370 to date.
‘The towed pinger locator deployed from the Australian Defence Vessel Ocean Shield has detected signals consistent with those emitted by aircraft black boxes,’ he told journalists. ‘Two separate signal detections have occurred within the northern part of the defined search area. The first detection was held for approximately two hours and 20 minutes. The ship then lost contact before conducting a turn and attempting to re-acquire the signal. The second detection on the return leg was held for approximately 13 minutes. On this occasion, two distinct pinger returns were audible. Significantly, this would be consistent with transmissions from both the flight data recorder and the cockpit voice recorder.’
Houston described this news as ‘a most promising lead’ and ‘probably the best information that we have had’.
But he still wanted to keep expectations within realistic bounds, telling journalists MH370 could not be confirmed as found until underwater cameras took shots of wreckage and established conclusively it was from a Boeing 777.
Houston and Leavy also advised the media pack about just how difficult the process of acoustic detection was. It was a very slow operation to tow the beacon locator device at only three knots, and with the length of cable, it took hours for the ship to turn around for a new pass. Unlike in air where sound travels in a straight line, Leavy explained, sound through the water is greatly affected by temperature, pressure and salinity.
Nonetheless, it was immensely encouraging news, and it got better. Two days later, on 9 April, Houston told journalists:
‘I can now tell you that Ocean Shield has been able to re-acquire the signals on two more occasions – late yesterday afternoon and late last night, Perth time.
‘The detection yesterday afternoon was held for approximately five minutes and 32 seconds. The detection late last night was held for approximately seven minutes. Ocean Shield has now detected four transmissions in the same broad area.’
And there was more good news, Houston said. The Australian Joint Acoustic Analysis Centre based at HMAS Albatross in Nowra, NSW, which Houston described as the Australian Defence Force’s ‘centre of excellence for acoustic analysis’, had analysed the pings, and determined that ‘a very stable, distinct, and clear signal was detected at 33.331 kilohertz and that it consistently pulsed at a 1.106 second interval’.
‘They, therefore, assess that the transmission was not of natural origin and was likely sourced from specific electronic equipment. They believe the signals to be consistent with the specification and description of a flight data recorder.’
It was the best single moment in the hunt for MH370 – before or since – for hopes the aircraft would be found. While still urging caution, Houston allowed just a bit of his own excitement to ebb out.
‘I’m now optimistic that we will find the aircraft, or what is left of the aircraft, in the not too distant future,’ he told the media pack.
Houston said the next move would be to deploy the autonomous underwater vehicle on Ocean Shield to find and get images of the wreckage – but not before the possibility of narrowing down the search area through more towing of the beacon locator had been exhausted. Houston wouldn’t put a fix on when that might be, but said the pings seemed to be getting weaker, which could suggest the batteries were running out.
Houston’s optimism was catching; in remarks he made in Shanghai for which he was later roasted by journalists, a few days later Abbott said, ‘We are confident that we know the position of the black box flight recorder to within some kilometres’.
It was a difficult period for the families of those lost on MH370. As news reports heralded the expectation that MH370 was about to be found and its secrets revealed, next-of-kin felt at least one element of closure might be at hand.
The Weeks family had been reluctant to hold a memorial service for Paul while the aircraft was still missing. One of Houston’s key jobs was to brief the families – Danica got a one-on-one session with Houston every Friday, and also personal updates in between when developments called for it. Danica said the impression she got from Houston at that point was that the aircraft was about to be located.
‘He did say he’d found the “ping” from the black boxes,’ Danica told me. ‘He said, “Go home, prepare your memorial, that’s it, we’re going to find the plane”. So I
set about preparing, doing songs, movies.’
Houston insists he always managed expectations, pointing out that at every turn he repeated the mantra that the aircraft was not found until visual confirmation of verified aircraft wreckage was in hand. But he said it was also not unreasonable for him to have been optimistic at that point based on the information provided. Houston said that, inevitably, when the series of four pings were picked up by the towed pinger locator, ‘of course, we got excited’.
‘We wondered if we had found it,’ he said. ‘There was quite a saga to this.’
The pings straddled the Seventh Arc, so all pieces of the search strategy fitted with the location of the pings. Nobody had jumped to conclusions, Houston said, and the RAN acoustic unit at Nowra was highly regarded. It had come back with a report that the signals were consistent with those from the beacon of a black box.
‘That’s when people started to say – it’s definitely down there,’ Houston said. ‘I was very hopeful, but I was very guarded.’ With the batteries on the beacon likely to run out at any moment, the searchers redoubled their efforts in the hunt for acoustic signals.
The cleverly adapted sonobuoys were deployed by the RAAF AP-3C Orion aircraft. As Leavy told journalists, the sonobuoys were a particularly useful tool at that point. The task force did not want to send another ship to join Ocean Shield, because the whole idea was to limit the sources of man-made noise. Ocean Shield itself had turned off all but absolutely essential equipment on board. The sonobuoys could cover a big area quickly without putting any moving parts in the water. Leavy explained the technology at a press conference.
The sonobuoys were parachuted out of the aircraft and the main component would float on the surface of the ocean and deploy a hydrophone 1000 feet below the surface of the ocean. The sonar buoy had a radio that transmitted the data back to the aircraft.
Each Orion could carry 84 sonar buoys on each mission, Leavy said.
Leavy later made an interesting revelation: the sonobuoys were single-use only; it could not have been cheap.
‘When the life of the sonar buoys expires, which is generally around eight hours after they are deployed, they do scuttle and sink to the seabed,’ Leavy said.
On 10 April, Houston announced another possible breakthrough: an Orion aircraft had ‘detected a possible signal’ via sonar buoys in the vicinity of Ocean Shield; just the next day, 11 April, he said it had turned out to be another red herring.
By then, it had been 34 days since MH370 went missing. The window was closing fast, but the efforts only intensified. Houston’s statement that day said Ocean Shield was making ‘more focused sweeps’, while the Orions would support that effort with three more sonobuoy missions that day.
‘A decision as to when to deploy the autonomous underwater vehicle will be made on advice from experts on board the Ocean Shield and could be some days away,’ he said.
The autonomous underwater vehicle was another critical tool in the hunt for MH370. They are amazing machines. They are unmanned, free-ranging, torpedo-shaped miniature submarines which have an extraordinary array of sensors. In their bodies, usually around six metres long, most carry side-scan sonar, a multi-beam echo-sounder, a sub-bottom profiler, a high-definition camera, a conductivity/temperature/depth sensor, a self-compensating magnetometer, a turbidity sensor, and a methane and laser sensor.
The most important pieces of equipment for this search were the side-scan sonar, which can create images of things on the sea floor; the multi-beam echo-sounder, which can produce three-dimensional images; and the magnetometer, which can confirm if objects are metallic.
In some cases, the machines can message robot ships known as unmanned surface vehicles about what they are doing, using acoustic positioning telemetry. They have onboard cameras and machine-vision software that can enable them to keep an eye on what’s ahead of them and dodge underwater cliffs or other obstacles. The autonomous underwater vehicles can be programmed to run a mission over many hours, returning to the surface where the information can be downloaded.
The side-scan sonar can produce some extraordinarily clear images, in a sort of sepia tone, of natural features and man-made objects on the sea floor, even though there is little or no light at extreme depths, by bouncing signals off them, much like radar.
In this case, the magnificent piece of AUV technology was called Bluefin-21, operated by private contractors Phoenix International.
At a press conference with Chinese journalists, Leavy spoke of the extraordinary way it would work: once deployed, Bluefin-21 would glide around 35 to 50 metres over the seabed, looking around 300–400 metres either side of its track.
By 12 April there had been no confirmed acoustic detections over the previous 24 hours. A couple more days passed without any more pings, and, on Day 38, the searchers assessed that could mean that the batteries on the underwater locator beacons were finally dead.
The big decision was taken. As Houston put it at a press conference on 14 April:
‘We haven’t had a single detection in six days. So, I guess it’s time to go underwater. Ocean Shield will cease searching with the towed pinger locator later today and deploy the autonomous underwater vehicle, Bluefin-21, as soon as possible.’
Houston braced journalists, the families, and the general public for a long, painstaking process.
‘Each mission conducted by the Bluefin-21 will take a minimum of 24 hours to complete,’ he told the press conference. ‘It will take the autonomous underwater vehicle two hours to get down to the bottom of the ocean. It will then be on-task for 16 hours. It will then take two hours to return to the surface and four hours to download and analyse the data collected. The first mission will see Bluefin-21 cover an area of approximately five kilometres by eight kilometres, an area of 40 square kilometres.’
As always, Houston urged caution.
‘And I would just say to everybody, don’t be over optimistic, be realistic and let’s hope, let’s hope that that the very strong signal that we were receiving is actually coming from the black box because that would be a really good outcome.’
This was, effectively, the only remaining chance on Houston’s watch to find MH370. He told journalists the ping picked up at the other end of the target search area by the Chinese vessel had been analysed and discounted.
‘So, at the moment, this is really all we’ve got,’ he said.
And so, as Houston put it to me, ‘Bluefin-21 started doing daily trips down to the deep.’
That night, amid considerable anticipation of all those involved, Ocean Shield launched Bluefin-21. What the JACC called the ‘focused underwater search area’ was defined as a circle of 10 kilometres in radius around the second towed pinger detection on 8 April.
One problem with Bluefin-21, according to Houston, was that it had limited depth – it could only descend to about 4500 metres, and again, some of the search area was deeper than that. The JACC report of 15 April said:
‘After completing around six hours of its mission, Bluefin-21 exceeded its operating depth limit of 4500 metres and its built-in safety feature returned it to the surface.’
In the 17 April media bulletin, the JACC seemed to be placing so much faith in Bluefin-21 that the undersea robot took on an almost independent intelligence and soul of its own, planning its own missions:
‘Overnight Bluefin-21 AUV completed a full mission in the search area and is currently planning for its next mission. Bluefin-21 has searched approximately 90 square kilometres to date and the data from its latest mission is being analysed.’
The issue of whether Bluefin-21 could go deep enough was solved – by taking on an ‘acceptable level of risk’ and going a bit deeper.
The days went by, about a dozen aircraft and a dozen ships scoured the surface of the southern Indian Ocean looking for wreckage, and Bluefin-21 went down to the deep, producing excellent son
ar images of a sea floor with nothing man-made on it.
On 21 April, the JACC media bulletin said:
‘This morning, Bluefin-21 AUV completed mission eight in the underwater search area. Bluefin-21 has searched approximately two thirds of the focused underwater search area to date.’
More days passed, and the bulletins reported that Bluefin-21 had searched 80 per cent, then 90 per cent, then 95 per cent of its target zone. Each bulletin had the same line: ‘No contacts of interest have been found to date.’
By the end of April, despite a massive effort involving military and civilian officials from many countries, and Australian volunteers, all the many aspects of the search had, in the end, got nowhere.
Not one item viewed or picked up from the sea had been associated with MH370.
An oil slick turned out to not be aviation oil.
Bluefin-21 had looked here, looked there, but all that came back from the sonar imaging was dull, lifeless Indian Ocean seabed. It was, Houston told me, deeply disappointing.
‘For everyone who was involved it was a big downer,’ he said. With heavy hearts of those involved, it had to be the end of the trail for this chapter of the hunt for Malaysia Airlines Flight MH370.
It was Prime Minister Tony Abbott who took the press conference at RAAF Pearce to call it quits – while at the same time announcing the next chapter. With Houston at his side, Abbott told the media pack on 28 April:
‘It is now 52 days since Malaysia Airlines Flight MH370 disappeared and I’m here to inform you that the search will be entering a new phase. I regret to say that, thus far, none of our efforts in the air, on the surface or under sea have found any wreckage.’
Abbott said the ‘new phase’ of the search would involve a different approach: rather than a surface search like the one just completed and a selective underwater hunt for the aircraft based on trying to find the pinger locators, the new effort would involve a massive, slow and methodical underwater survey of the seabed around the Seventh Arc.
