by Ean Higgins
The two ‘black boxes’ are the key element of the grail quest to work out what happened to Malaysia Airlines Flight MH370. The flight data recorder monitors and stores data of hundreds of parameters of the flight, from speed, altitude, direction, and aircraft attitude to movement of the control surfaces, throttles and instruments by the pilots. The cockpit voice recorder uses microphones to record every sound in the cockpit, whether it be voices of the crew, warning alarms, or in a radical case, an explosion or gunshot.
Each black box has attached to it an underwater locator beacon or ‘pinger’ which emits an automatic acoustic signal or ‘ping’ at a certain frequency which can be picked up by acoustic listening devices operated by ships looking for it.
The search strategy for the underwater locator beacons was, in some respects, relatively straightforward: they would be in a debris field where the aircraft came down around the Seventh Arc. But the surface search for bodies or debris had to contend with a major problem related to the passage of time since MH370 went down. That search band along the Seventh Arc was, of itself, relatively narrow. It would have been contained and realistically locatable for a fairly fast and thorough visual search by aircraft and ships had it started on the day MH370 went down, or a day or so after that.
The problem for Houston was that three weeks had passed. By the time the JACC was established, the winds and ocean currents would have taken what was left of MH370 considerable distances from the crash site, and in not fully predictable directions.
The planners ‘drifted’ each proposed section of the search – they used three different computer models with sea current and wind algorithms to calculate an expanded area to look, fanning out from where the aircraft might have come down along the Seventh Arc. The longer the search went on, the farther debris could have drifted, and so the ‘drifting’ models took that into account and the target area kept expanding.
The currents and winds were moving whatever floating debris there was between 0.5 to 2 knots per hour, so the search area was constantly growing exponentially. One technique to keep track of the search zone was to drop 31 self-locating data marker buoys throughout the Indian Ocean, which transmitted their position using satellite technology. This would tell the hunters where the water was physically going.
The total target area for the aircraft and ships over the 42 days from the day the Australians assumed the surface search for MH370 until it was eventually called off came to 4.7 million square kilometres, equivalent to about half the size of Australia or the continental United States, and all of western Europe.
Lloyd said AMSA’s liaison with Defence was an example of how it’s best not to overthink things.
‘Basically, we said we need 10 aircraft a day for 30 days searching the middle of the Indian Ocean, go do it.’
But as the drift models continued to move north-west with the currents, Lloyd told the IPA gathering, so the logistics of the aerial search became ever more challenging.
‘Even with basically the best military aircraft in the world, we were flying four hours, two hours on scene, and four hours back,’ Lloyd said. ‘I think we actually nearly had Western Australia run out of aviation fuel at one point, but of course Defence took care of that.’
The surface search was carried out seriously and meticulously – whenever a review of satellite imagery or aerial reconnaissance showed what looked like possible MH370 debris, it was investigated.
‘All of them were checked out, and they were rubbish from fishing boats and the like,’ Houston explained. ‘The ocean was not as pristine as we thought it might be. None gave a lead.’
The surface search just kept getting bigger, with more and more search plane sorties, as such aerial missions are known, and ship patrols. On 8 April, the JACC issued its morning bulletin saying ‘up to eleven military planes, three civil planes and 14 ships will assist in today’s search for missing Malaysia Airlines Flight MH370.’
RAAF Pearce, 35 kilometres north of Perth, was where the main aerial search was launched from and a swarm of activity. The number and range of people involved was several hundred including military men and women, civilian pilots and support crews, AMSA staff, but also many volunteers. On 4 April, 26 State Emergency Service volunteers from Western Australia, New South Wales and Victoria flew as air observers on three of the civil aircraft.
It was at RAAF Pearce that Najib and Abbott made a joint show of force on 3 April to encourage the international search effort and thank those involved.
‘I know it is a daunting task to go out there in very inclement weather, in very challenging circumstances,’ the Malaysian Prime Minister said. ‘Malaysia is indeed grateful for your courage and for your commitment.’
Najib also announced an initiative which was to have quite significant implications down the track: Australia had accepted Malaysia’s invitation to participate as an accredited representative in the air crash investigation and would continue to work with Malaysia to draw up a comprehensive agreement on the search.
The countries of the world have an agreement under the International Civil Aviation Organisation known as Annex 13, which provides a protocol for how major air crash investigations are to be conducted. Under the agreement, the country of registration of the aircraft concerned – in this case Malaysia, where 9M-MRO was registered – has responsibility for the overall investigation. But that country can invite ‘accredited representatives’ from other nations – usually members of their respective countries’ air accident investigation agencies – to be members of an international panel participating in the inquiry. Those can be nations which have an interest because they had a significant number of their citizens on the aircraft or the accident occurred in their territory, or because their investigation agencies have particular expertise.
With an accredited representative on the investigation panel, this meant the Australian government, and more specifically the ATSB, had a share of the responsibility for the process and outcome of the Malaysian-led investigation into the loss of MH370.
Contrary to some of the more sceptical interpretations, Houston insists the Malaysian government was absolutely committed to solving the mystery of MH370. He said Najib periodically sought briefings direct from him on how the search was progressing, as did Hishammuddin.
‘They wanted to find it. I would say the Prime Minister was quite down because of what had happened,’ Houston said.
At one point when he was meeting with Najib, Houston recounted, who should pop up with the Malaysian Prime Minister but the dashing Jean-Paul Troadec, the French celebrity air crash investigator. Troadec came to international fame as the highly visible president of the French Bureau of Inquiry and Analysis in Civil Aviation Security, whose acronym is the BEA, during the hunt for Air France Flight 447, a maritime search which bore some similarities with that for MH370, but also a lot of differences.
It turned out that Troadec, an aerospace engineer, pilot and one-time military parachutist, had been engaged by the Malaysian government as a consultant to advise on the search for MH370.
‘He’s a fairly charismatic sort of person,’ Houston said of Troadec.
At a press conference later on, Hishammuddin mentioned that Troadec had been brought on board, proudly saying, ‘We’ve got the man himself advising us.’
Houston, who had himself been a pilot in dozens of search and rescue missions, threw himself into the complex task of coordinating the aerial and surface search for MH370, but he revealed to me he did not have huge hopes that this part of it would yield results. The Malaysians and the JACC had had a good look at the case of AF447, which was likely one of the reasons Troadec’s advice was sought.
The brand new Airbus A330–203 crashed into the Atlantic Ocean on a flight from Rio de Janeiro to Paris on 1 June 2009. The investigation determined the aircraft’s pitot tubes, which measure airspeed, became blocked by ice crystals during a tropical storm
, causing the autopilot to disengage. The pilots took control but reacted badly, over-correcting and pointing the nose too high, and the aircraft stalled and pancaked into the ocean with the loss of all 228 people on board.
The black boxes yielded some chilling details of the last few minutes of the flight, some of which had a very French flavour. Just minutes before the crisis, the captain, 58-year-old Marc Dubois, had told the two co-pilots he had not got much sleep the night before because he had been out on the town in Rio with his girlfriend, off-duty Air France flight attendant and occasional stage singer Veronique Gaignard, who was on board the flight. He had gone to the two-berth rest compartment behind the cockpit for a doze – he was required under Air France regulations to rest for a portion of the long-distance flight. Reports said it took a minute or so for Dubois, after being summoned by the alarmed and comparatively inexperienced co-pilots, to return to the cockpit. Once there, he encountered a scene of panic and confusion as the co-pilots struggled to save the aircraft: he immediately ordered them to get the nose down, but one pushed his stick forward and the other pulled his up, cancelling each other out, and then it was too late. The terrain proximity warning sounded, and one of the co-pilots said:
‘F*** we’re dead!’
Troadec told ABC News Gaignard was not part of the investigation. The agency was ‘not interested’ in the ‘private life of the pilot’, Troadec told the news network.
The reason the dramatic full story of the crash of AF447, and the detailed series of events which caused it, became known was because the aircraft’s black boxes were recovered. The flight data recorder told everything about the pilots’ control inputs, the attitude and speed of the aircraft, and so on, enabling investigators to reconstruct with great precision the ‘pancake’ stall and how it happened. The cockpit voice recorder revealed the conversations of the flight crew and the warning alarms, right down to the end where the terrain proximity warning alarm went off.
In the case of AF447, the searchers were able to get a fair fix on where the aircraft might be because its route was known and automatic ACARS signals gave its position about every 10 minutes. The wreckage and an oil slick were spotted the day after the accident.
‘With Air France 447 they found a lot of bodies and wreckage,’ said Houston. ‘After a while they found nothing more. They only found stuff in the water early on, and, by Day 16, there was nothing more that they found.’
By the time the JACC was established, Houston noted, it was Day 22 since the loss of MH370.
‘Here we are, the JACC, set up 30th of March,’ he said. ‘It was well past the optimum time to be looking for surface debris. We ended up in a situation where the best time for the visual search was lost.’
Recovery of debris would be useful in the air crash investigation, and recovery of any bodies would be macabre but would nonetheless provide some closure for the families involved and possibly reveal further clues to what happened. But given the passage of time, the amount of drift would provide some, but probably not a lot, of real guidance to the precise location of MH370 on the seabed.
Incredibly, while in the case of Air France 447 some floating debris had been recovered within days, it took nearly two more years for underwater searches to find the main aircraft wreckage and black boxes. So the best hope for finding MH370, Houston said, was to track down the ‘pingers’, the underwater locator beacons attached to the black boxes.
The flight data recorder and cockpit voice recorders fitted to MH370 were equipped with Dukane DK100 underwater acoustic locator beacons that activate on immersion in salt or fresh water. They ‘ping’ at the rate of one pulse per second and at the operating signal frequency of 37.5 kilohertz.
The critical element in the equation was this: the beacons were equipped with batteries designed to operate for a minimum of 30 days after immersion. So Houston and his colleagues faced a race against time.
‘What were we looking for? The prime focus was trying to locate the locator beacon,’ Houston said. ‘The big priority was to try to pick up the flight data recorder, and that would be a ping from the deep.’
Houston knew a lot about locator beacons – he’d gone hunting for them flying helicopter search and rescue missions in the wilds of Papua New Guinea, looking for downed aircraft.
‘It’s unmistakable,’ Houston said. ‘The closer you get the louder it gets.’ So, find the ‘ping from the deep’, and you find MH370 – it sounded straightforward. But it turned out to be an extraordinarily frustrating, tricky, confusing and ultimately soul-destroying exercise.
There were, in fact, four vessels and several aircraft deployed in the bid to find MH370’s locator beacon.
Ocean Shield had one version of the technology – a yellow device on loan from the US Navy, looking a bit like a delta wing model airplane that was towed deep behind the ship to listen for the pings from the underwater locator beacons.
The crew of the Chinese Maritime Safety Administration vessel MV Haixun 01 were operating Benthos pinger detector equipment – another brand of acoustic devices which pick up the pulses from the black boxes – from a rescue boat.
The British Royal Navy’s hydrographic vessel HMS Echo had a sophisticated made-for-purpose hull-based detection device.
Then there was an unexpected and extremely welcome volunteer: the British Royal Navy’s Trafalgar Class nuclear submarine HMS Tireless which, because of the very nature of undersea warfare technology, had some of the most advanced acoustic detection equipment in the trade.
‘The British submarine had been patrolling in South-east Asia, and offered to help,’ Houston said.
Just how much the British told the Australians about exactly what Tireless was doing is a moot point, Houston hinted, but he expected ‘the senior officer would have had some idea where the nuclear submarine was’.
Then the Australian Defence Force and the defence industry worked on something else: developing the capacity of sonar buoys, or sonobuoys. The sonar buoys were, presumably, designed for anti-submarine warfare, but the defence and industry tech heads managed to adapt them to pick up the frequency of the underwater locator beacons. It looked promising; the concept was to deploy AP-3C Orion aircraft to drop sonobuoys at a depth of 300 metres beneath the ocean surface. One sortie was capable of covering an area of approximately 3000 square kilometres.
Unlike the surface search which had to account for drift, the acoustic signal hunt could be restricted to the relatively narrow band around the Seventh Arc – the assumption was that the aircraft would have come down after fuel exhaustion and the main, heavy metal parts of the fuselage and the engines would have sunk quickly and pretty much straight down.
But time was running heavily against Houston and his colleagues. MH370 disappeared on 8 March; the batteries in the Dukane underwater locator beacons were required to keep emitting pings for 30 days, and the manufacturer said at best they could go for 40 days. By the time Ocean Shield and Echo got on station it was early April – if the 30-day minimum limit expired on time that left only until 7 April to find the signal. If luck was with the searchers and the underwater locator beacons’ batteries held out to the maximum, the window extended to 17 April, but that could not be counted upon.
It was nuanced from the start; while the locator beacon signal can usually be detected two kilometres or three kilometres away, sometimes even up to four kilometres, in one report the ATSB cautioned:
‘Many conditions influence the actual detection range, environmental noise, the ability of the water to conduct the acoustic signal, and the sensitivity of the equipment used to make the detection. In reality for a robust search a maximum range to target area of approximately 1 km is used.’
But almost as soon as each surface vessel got on station, Houston told the author, ‘we got the ping from the deep’.
The first was heard by the British ship Echo, on 2 April. The excitement at the JACC wa
s enormous, but this signal was quickly discounted. ‘False alerts may be experienced from biological sources such as whales, or interference from shipping noise,’ the JACC said the next day.
In this case, it was later established, the ship was pinging itself: the ATSB reported that, following tests, ‘this detection was discounted as being an artefact of the ship’s sonar equipment’.
Then things became more serious.
On 4 April, Ocean Shield and Echo mounted a sweep of a single 240-kilometre track along the Seventh Arc, converging on each other as their pinger locators listened for the beacon from MH370’s black boxes.
The military side of the search operation had been designated Joint Task Force 658, and its commander, Commodore Peter Leavy, said the two ships and their towed pinger detector equipment would be operating at a crawl of about three knots to enable them to search at depths of 3000 metres or more.
‘The search using sub-surface equipment needs to be methodical and carefully executed in order to effectively detect the faint signal of the pinger,’ Leavy said in a statement that day.
While the Australians and the British were proceeding methodically and carefully in executing their sweep for the black boxes, all hell broke loose when it came to the Chinese.
Chinese media reports went wild on suggestions the Chinese vessel Haixun 01, operating around the southern extreme of the Seventh Arc target search area, had found MH370, or at least the pings from its black boxes. China’s official Xinhua news agency reported that a beacon locator on board the Chinese search ship had picked up a signal at a frequency of 37.5 kilohertz – the black box locator beacon frequency.
It was one of several occasions where Houston had to hose down expectations.
‘I have been advised that a series of sounds have been detected by a Chinese ship in the search area,’ Houston said in a statement on 5 April. ‘The characteristics reported are consistent with the aircraft black box. A number of white objects were also sighted on the surface about 90 kilometres from the detection area. However, there is no confirmation at this stage that the signals and the objects are related to the missing aircraft.’