A sophisticated unmanned underwater vehicle that can scan the silt-filled seafloor of the Indian Ocean today emerged as the next best option for weary searchers hunting for the missing Malaysian jet.
But even the Bluefin-21, one of the US Navy's best tools, faces plenty of challenges in scouring the seabed at 4,500 meters to locate the Boeing 777-200 plane carrying 239 people that mysteriously disappeared on March 8, experts said.
The torpedo-like device can create a three-dimensional sonar map of the sea floor and will search for wreckage in an area defined by four signals, apparently from the black boxes of Flight MH370 heard last week by ships scouring the Indian Ocean.
Till now, search teams used a towed pinger locater to listen for signals from the plane's black box flight recorders. But no new signals have been heard since April 8, amid concerns the flight recorders' batteries have expired.
"We haven't had a single detection in six days so I guess it's time to go underwater," the Australian chief search coordinator for MH370, Angus Houston said here today.
"When it reaches the appropriate depth, it will turn on its sensors," David Kelly, the president and CEO of manufacturer Bluefin Robotics, said.
"It will then run what's called the lawn mower pattern, which is a series of parallel lines or tracks, where it will go back and forth just like mowing your lawn," Kelly said.
The Bluefin-21 will be launched in the most probable area of the pings that were detected by the Australian defence ship Ocean Shield.
From there, it will plunge to a depth of 4,000 to 4,500 meters, the US Navy said.
The Bluefin-21's first mission will cover about 40 square kilometers. It will probably take anywhere from six weeks to two months to scan the entire search area, the US Navy said.
The operation is time-consuming because the vehicle crawls at the pace of a leisurely stroll, CNN quoted Sylvia Earle, an oceanographer from National Geographic, as saying.
Houston said the bottom of the sea area probably has a lot of silt, which can "complicate" the search for the debris.
He also cautioned against high hopes that the underwater vehicle will find wreckage.
"It may not," he said. "This will be a slow and painstaking process."
The vehicle has a 24-hour cycle, so it can be deployed only once a day. And no information will be available until the end of each cycle, Houston said.
It will take two hours for the Bluefin-21 to get down to the search area. Then it will scour the ocean bed for 16 hours and take another two hours to resurface. After that, it will take another four hours to download and analyse the data collected, Houston said.
Once the debris field is found, other equipment such as remotely operated vehicles would be brought in to recover the black boxes, Earle said.
