China mulls deploying manned submersible to trace MH370

Beijing: China is planning to deploy its indigenous deep sea manned submersible to locate the wreckage of the missing Malaysian airliner, even as searchers zeroed in on an area of the remote Indian Ocean.

Experts say the depth of the water in the 50-km radius earmarked by search teams can exceed 4,500 metres, making it challenging for the searchers to locate the plane.

Currently, a US Navy pinger locater and an unmanned submersible Bluefin-21 underwater autonomous vehicle have been deployed in the coast off Perth, Australia to find the black boxes of MH370, the signals from which seem to have died.

But once the black boxes are located, any salvage operation must contend not only with strong currents and an absence of natural light, but also crushing pressure that only a handful of manned vessels in the world can withstand.

With 154 of the 239 people, on board the ill-fated Beijing-bound flight, from China, Beijing is under pressure to find out what happened to the Malaysian airliner.

Chinese experts think that Jiaolong, China's first manned deep-sea submersible, could be deployed as it has the deep-sea retrieving capability.

In 2012, Jiaolong, or Sea Dragon, achieved a record dive depth of more than 7,000 metres in the Pacific's Mariana Trench.

The Jiaolong can stay underwater for more than 10 hours but its battery power limits it to covering only a few kilometres of sea floor each dive.

China is the fifth country after US, France, Russia and Japan, to have developed a deep diving submersible.

The operational limit of Jiaolong is about 7,000 metres and it has used its robotic arm to retrieve samples at about half that depth, said Feng Dong, a researcher with the Key Laboratory of Marginal Sea Geology under the Chinese Academy of Sciences.

Reaching the wreckage and recovering the black boxes would pose a challenge for the crew but it could be accomplished with enough planning, Feng was quoted by the Hong Kong-based South China Morning Post.

Feng, who has been inside Jiaolong, said visibility was difficult at such depths, given the total lack of natural light, the crew would need the plane's exact location.

The robotic arm of the submersible works much like a human one, allowing it to firmly grip objects.

But it could not carry large or heavy objects to the surface. Handling pieces of the wreckage might first require hardware changes.

"The crew might face many challenges because no one has done this before. Deep-sea work is a risky business that requires extra care," Feng said.

China could send a robotic submersible, but it did not have one equipped with a mechanical arm that was capable of operating at the required depths.

Jiaolong and its mother ship, Xiang Yang Hong 9, are docked at the National Deep Sea Centre in Qingdao, Shandong.

An official with the centre's administrative office was quoted by the Post as saying the submersible would need preparation before any launch.

"The whole world's eyes are on us, creating a lot of pressure," he said.

"But the job is delicate with many technological and political concerns. It will not be done in haste."

China also has ships with sonar imaging devices that could scan the site and yield high-definition images that could aid salvage teams,  Professor Yang Yichun, a researcher with the academy's Key Laboratory of Noise and Vibration Research said.

"I can't give anything specific on the highest resolution - that is classified - but our devices can find a section of sea cable at great depth, so 'seeing' the wreckage of a plane would not be a problem," Yang said.

"We would be able to clearly see windows, wings, the tail or other external features of the plane allowing us to determine the precise location.

"After analysing the sonar images, we can make a plan on how to approach the wreckage and retrieve the black box," he said.