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 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 seems 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 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.