Locating, retrieving plane's black box still time-consuming process

Despite the progress being made, experts have warned that the search for Malaysia Airlines flight MH370 will be a long process due to its complexity.

They urged the public to be patient and rational, amid the excitement caused by the latest detection of pulse signals in the southern Indian Ocean which may lead search teams to the aircraft's crucial black box.

"Search vessels have picked up the so-called 'ping' signals but they are still far from locating and retrieving the black box," said Wu Peixin, an aviation expert in Beijing.

The black box, which contains a flight data recorder and a cockpit voice recorder, is fitted with an underwater locator beacon that emits a pulse if its sensor touches water. The pulse "pings" once a second for 30 days until the battery runs out.

MH370 vanished on March 8, en route from Kuala Lumpur to Beijing. The plane carried 239 people, including 154 Chinese passengers.

"They must verify the signals and make sure they were from the MH370's black box, then they will draw up a map of the seabed area where the device could be located," Wu told China Daily on Sunday. "Given that the black box's battery will run out on Monday or Saturday at the latest, the searchers are actually racing against the clock."

Angus Houston, head of the Joint Agency Coordination Center in Australia that leads the multinational search, said on Sunday that even if the signal received by the Chinese ship is confirmed to be related to MH370, retrieving the black box will be a very difficult and long process.

"The water in which Haixun 01 is working at the moment is 4,500 meters deep which is incredible, so any recovery operation is going to be very challenging and very demanding and will take a long period of time," said Houston.

"First of all, we have to establish the fact that there's something down there, we are a long way from making that conclusion," he said.

The Chinese patrol ship Haixun 01 detected pulse signals with a frequency of 37.5kHz per second in the Indian Ocean west of Perth on Friday and Saturday, reported Xinhua News Agency, which has a reporter aboard the ship.

A number of floating objects have also been sighted on the surface about 90 km from the Haixun 01's detection area.

The black box is at the top of the searchers' recovery list because it can provide the best clues to explain what happened to the ill-fated jet. But the search for other parts of the Boeing 777-200 has proved equally difficult.

"We should understand that searching for small objects floating in the sea or underwater is an extremely complicated, laborious and time-consuming task," Wu said. "Perseverance and patience will be required before we find any solid evidence."

Wang Ya'nan, deputy editor-in-chief of Aerospace Knowledge magazine, said the search will become even more demanding if the black box cannot be located before April 12, when the device is expected to lose power and stop emitting signals.

In the search for the Air France flight 447, which crashed into the Atlantic Ocean on June 1, 2009, it took nearly two years for search teams to retrieve the black box, even though they had located the crash site within a first week of the accident, Wang said.

The Chinese media have urged the public and relatives of the 154 Chinese nationals on the missing jet to voice their concerns and requests in a "proper and reasonable manner".

In an editorial published on Thursday, the People's Daily said irrational words or actions toward a specific nation or individual will neither help to uncover the truth behind the tragedy nor protect the rights and interests of the relatives of the missing Chinese passengers.

All the nations involved in the search need the cooperation and support of the people, it said.

On Friday, the China News Service also reported that members of the public have urged Chinese citizens to take an impartial view of the incident and avoid irrational remarks or actions.

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