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Missing Malaysia Airlines flight MH370: Underwater mission aborted early as search area proves too deep for submarine
Missing Malaysia Airlines flight MH370: Underwater mission aborted early as search area proves too deep for submarine
(about 1 hour later)
The search area for the missing Malaysian jet has proved too deep for a robotic submarine which was hauled back to the surface of the Indian Ocean less than half way through its first seabed hunt for wreckage and the all-important black boxes, authorities have said.
The first underwater attempt to locate wreckage from the missing Malaysia Airlines flight MH370 has ended in disappointment after the search area proved too deep for the submersible Bluefin 21 vehicle.
Search crews sent the Bluefin 21 deep into the Indian Ocean on Monday to begin scouring the seabed for the missing Malaysia Airlines Boeing 777 after failing for six days to detect any signals believed to be from its black boxes.
Just six hours into an initial planned 16-hour mission, the seabed dropped beyond the sub’s maximum depth limit of 4,500 metres (15,000 feet).
But after only six hours of its planned 16-hour mission on the sea bed, the autonomous underwater vehicle exceeded its maximum depth limit of 4,500 metres (15,000 feet) and its built-in safety feature returned it to the surface, the search coordination centre said in a statement today.
The authorities leading the search had described the Bluefin 21’s efforts as their best hope in finding the Boeing 777’s “black box” flight recorders, from which no signal has been detected for a full week.
What if anything it might have discovered during the six-hour search was still being analysed, it added.
Search crews had previously warned that the ocean’s depth would stretch the unmanned submersible to its very limit. The Bluefin 21 has a built-in safety feature which forces it to return to the surface once its limit is exceeded.
The Bluefin 21 will resume the search today when weather conditions permit, it said.
The Perth, Australia-based search coordination centre said that the data gathered during the brief search was still being analysed – but with even a full mission covering just 40 square kilometres, it will only have scanned a tiny portion of the overall search area.
Search authorities knew that the primary wreckage from Flight MH370 was likely lying at the limit of the Bluefin's dive capabilities. Deeper diving submersibles have been evaluated, but none is yet available in the search area.
Weather permitting, the sub will resume its search later today. Vehicles with a deeper range have been requested by the search organisers, but until one arrives Bluefin 21 will remain the best and only option.
The sub would have been programed to return to the surface once it exceeded the 4,500-metre limit, but a safety margin would also have been included to protect the device from damage if it went a bit deeper, said Stefan Williams, a professor of marine robotics at the University of Sydney.
Meanwhile, officials were still waiting for the results of analysis on an oil slick found about 5.5km (3.4 miles) from the area where the last underwater sounds were detected, said Angus Houston, the head of a joint agency coordinating the search off Australia's west coast.
“Maybe some areas where they are doing the survey are a little bit deeper than they are expecting,” he said. “They may not have very reliable prior data for the area, so they have a general idea. But there may be some variability on the sea floor that they also can't see from the surface.”
The process will take several days, and while Houston said the oil does not appear to be from any of the ships in the area, he cautioned against jumping to conclusions about its source.
Meanwhile, officials were investigating an oil slick about 5,500 metres (3.4 miles) from the area where the last underwater sounds were detected, said Angus Houston, the head of a joint agency coordinating the search off Australia's west coast.
Australian Prime Minister Tony Abbott raised hopes last week when he said authorities were “very confident” the four strong underwater signals that were detected were from the black boxes on MH370, which disappeared on 8 March during a flight from Kuala Lumpur, Malaysia, to Beijing with 239 people on board.
Crews have collected an oil sample and are sending it back to Australia for analysis, a process that will take several days. Houston said it does not appear to be from any of the ships in the area, but cautioned against jumping to conclusions about its source.
But Houston warned that while the signals are a promising lead, the public needs to be realistic about the challenges facing search crews in the extremely remote, deep patch of ocean — an area he called “new to man”.
The Bluefin 21 can create a three-dimensional sonar map of any debris on the ocean floor. But the search in this area is more challenging because the seabed is covered in silt that could potentially cover part of the plane.
“What they're going to have to be looking for is contrast between hard objects, like bits of a fuselage, and that silty bottom,” Williams said. “With the types of sonars they are using, if stuff is sitting up on top of the silt, say a wing was there, you could likely see that ... but small items might sink down into the silt and be covered and then it's going to be a lot more challenging.”
The search moved below the surface after crews picked up a series of underwater sounds over the past two weeks that were consistent with signals from an aircraft's black boxes, which record flight data and cockpit conversations. The devices emit “pings” so they can be more easily found, but their batteries only last about a month and are now believed dead.
“Today is day 38 of the search,” Houston told a news conference on Monday. “We haven't had a single detection in six days, so I guess it's time to go under water.”
Australian Prime Minister Tony Abbott raised hopes last week when he said authorities were “very confident” the four strong underwater signals that were detected were from the black boxes on Flight 370, which disappeared on 8 March during a flight from Kuala Lumpur, Malaysia, to Beijing with 239 people on board, mostly Chinese.
But Houston warned that while the signals are a promising lead, the public needs to be realistic about the challenges facing search crews in the extremely remote, deep patch of ocean — an area he called “new to man.”
“I would caution you against raising hopes that the deployment of the autonomous underwater vehicle will result in the detection of the aircraft wreckage. It may not,” Houston said. “However, this is the best lead we have, and it must be pursued vigorously. Again, I emphasize that this will be a slow and painstaking process.”
“I would caution you against raising hopes that the deployment of the autonomous underwater vehicle will result in the detection of the aircraft wreckage. It may not,” Houston said. “However, this is the best lead we have, and it must be pursued vigorously. Again, I emphasize that this will be a slow and painstaking process.”
Houston, a retired Australian chief air marshal, called the search “one of the largest search and rescue, search and recovery operations that I've seen in my lifetime.”
Houston, a retired Australian chief air marshal, called the mission “one of the largest search and rescue, search and recovery operations that I've seen in my lifetime”.
The Ocean Shield had been dragging a US Navy device called a towed pinger locater through the water to listen for any sounds from the black boxes' beacons.
Stefan Williams, a professor of marine robotics at the University of Sydney, explained that while the “pings” detected by the Australian navy’s Ocean Shield vessel were recorded at a specific depth, the search crews knew relatively little around the surrounding ocean floor.
The Bluefin sub takes six times longer to cover the same area as the ping locater, and the two devices can't be used at the same time. Crews had been hoping to detect additional signals before sending down the sub, so they could triangulate the source and zero in on where the black boxes may be.
“Maybe some areas where they are doing the survey are a little bit deeper than they are expecting,” he said. “They may not have very reliable prior data for the area, so they have a general idea. But there may be some variability on the sea floor that they also can't see from the surface.
The submarine takes 24 hours to complete each mission: two hours to dive to the bottom, 16 hours to search the seafloor, two hours to return to the surface, and four hours to download the data, Houston said.
“What they're going to have to be looking for is contrast between hard objects, like bits of a fuselage, and that silty bottom,” Williams added. “With the types of sonars they are using, if stuff is sitting up on top of the silt, say a wing was there, you could likely see that ... but small items might sink down into the silt and be covered and then it's going to be a lot more challenging.”
The black boxes could contain the key to unraveling the mystery of what happened to Flight 370. Investigators believe the plane went down in the southern Indian Ocean based on a flight path calculated from its contacts with a satellite and an analysis of its speed and fuel capacity. But they still don't know why.
Around 11 ships and as many planes join the visual search of the surface of the Indian Ocean on Tuesday, scouring an area over 62,000 square km (24,000 square miles), around 2,200 km (1,400 miles) northwest of Perth.
But Houston said the visual search operation will end in the next two to three days. Officials haven't found a single piece of debris confirmed to be from the plane, and he said the chances that any would be found have “greatly diminished.”
It is expected to be one of the final attempts to find floating debris, with more than a month of searches has so far not turning up a single item linked to the plane. Houston yesterday described the chances of now finding any wreckage on the surface as “greatly diminished”.
“We've got no visual objects,” he said. “The only thing we have left at this stage is the four transmissions and an oil slick in the same vicinity, so we will investigate those to their conclusion.”
Up to 11 planes and as many ships were to join Tuesday's search over 62,000 square kilometers (24,000 square miles), 2,200 kilometers (1,400 miles) northwest of Perth.
