Xinhua Beijing April 14 call: Chinese naval and air force on the 14th the first joint search Search Malaysia Airlines passenger plane lost contact with the same mission in the southern Indian Ocean region. Australian side that day, since the past few days and then did not detect underwater pulses, Australia will stop using towed sonar, enable the "Bluefin tuna" AUV conducted undersea search.

In the morning, perform air search mission of the Chinese Air Force planes into the mission sea, and naval ship formation Jinggangshan Cooperative launched a search. By using the parallel search method Jinggangshan ship and shipboard equipment through continuous lookout personnel search suspicious floating sea, air force planes to more than 200 meters altitude observe sea.

Navy maritime rescue command post command group leader Zhou said Minco, sea and air joint search is the most effective way to search. "In the case of sea and air to establish direct communication links, airplanes When discovered, can be notified immediately rushed to the suspected location of surface ships to verify."

Australia Search Malaysia Airlines Flight 370, general coordinator of the Joint Coordination Centre Angus? Houston on the 14th held a press conference, said the aircraft black box because the theoretical life of the battery has expired and has been six days did not detect any suspicious signal, the Australian warship "Ocean Shield "was equipped with the towing sonar and" Orion "patrol aircraft to put sonobuoy based exploration activities will come to an end," bluefin tuna "AUV will be put into use as soon as possible. According to the conference site in the United States Navy technical staff revealed that AUV will be in Beijing at 17:00 the same day into the water enabled.

Houston says, "Ocean Shield" carrying towing sonar to capture the fourth suspect signal, wherein the first signal is particularly strong, expert analysis and found that all of its characteristics meet the artificial device transmits a signal, the signal emitted by the aircraft black box locator very similar. According to this signal, it determines the starting point "bluefin tuna" sea search.

Houston said, "bluefin tuna," the first underwater action is very important, the data collected by this action will tell roughly Availability operator seabed environment. He was "cautiously optimistic" attitude towards the underwater search.

According to him, "bluefin tuna" to draw 3D high-resolution map using sonar on the seabed, to determine whether there is any suspected search area lost to aircraft objects. Currently identified first submarine sonar scanning area of ​​40 square kilometers, the sea bed in the area is relatively flat, but the seabed silt are more likely to increase the search difficult. Houston said, "bluefin tuna" will be the first probe to find a submerged submarine areas near the signal, an area of ​​about 40 square kilometers. However, this equipment move fast enough, each task will take at least 24 hours. Despite running "Bluefin tuna" may be further away from the wreckage found, but Houston also re-emphasized, can not guarantee results.

Given the focus of the search operation has been transferred AUV underwater search, Houston said that the sea and air search operations next week will be decided later in consultation countries involved in the search.

On the same day, the US Seventh Fleet press officer Daniel? 马齐尼亚克 said in a statement via e-mail, "bluefin tuna" intends to sink into the underwater range of 4000-5000 meters, about 35 meters from the sea bed, and in this a high degree of data collection.

According 马齐尼亚克 reports, the US military to provide towing sonar and "bluefin tuna" Every time only one device can be deployed to perform tasks to detect the water, so at this stage will be removed boxes sonar, change Enable "bluefin tuna." AUV approximately every 24 hours during operation, of which 16 hours for underwater detection, four hours for downloading the detected data.

The statement said that since the AUV to detect regions of the same area is completed with 6 times more than when towed sonar expected AUV may need six weeks to two months to complete this piece of the search area of ​​investigation test, scanning.

Further reading:

. a "bluefin tuna -21" works:

This "bluefin tuna -21" Autonomous Underwater Vehicle Massachusetts bluefin tuna Robotics developed and manufactured by nearly 4.9 meters in length, 0.5 meters in diameter and weighs 750 kg, the maximum dive depth of 4500 m, longest underwater action time of 25 hours.

Bluefin tuna Robotics is a research and development company specializing in deep-sea exploration equipment, under which there are many models of Autonomous Underwater Vehicle. "Bluefin tuna -21" was purchased by an American defense contractor and supplied to the US Navy.

? CEO of bluefin tuna Robotics David Kelly said: "The work of this device as lawnmowers to repair your lawn grass."

After being put in to the seabed, "bluefin tuna -21" will launch submarine sonar scan pulse, the pulse will spread in an arc in both directions. "Bluefin tuna -21" will receive the reflected sound waves within the pulse range of objects, using the "acoustic shadow" to judge the height of objects and forms an image.

However, the data "bluefin tuna -21" can not be collected at the time of the seabed to offshore operations researchers transmission, image experts must be "Bluefin tuna -21" End submarine surfaced after a search mission to "read" an image is formed.

b. delivery timing

Provided by the US Navy, "bluefin tuna -21" and towed sonar was deployed in the Australian Navy "Ocean Shield" was supply ship.

However, "bluefin tuna" has been "on hold", the reason is that equipment and towed sonar can not be used simultaneously, and search far less efficient than dragging sonar.

In the same piece of water, the two instruments use sound waves to detect interfere with each other, and therefore can not be used simultaneously. In fact, sonar and signal source in the water, a deep sea, which a few kilometers away from any environmental changes could result in a loss of signal. Even a fish swim across, may cause interference to the signal detection.

Asked why not, "bluefin tuna" instead of sonar search, Houston said, the same time the sonar search area equivalent to "bluefin tuna" six times, scanning the seabed is a very slow, very hard work .

"Bluefin tuna" to take advantage of the side sonar and video cameras dive search, but only an apparatus assembly. Normally, it is the first to use sonar, found suspicious targets dive again on the camera after modification, the search provides underwater images. (Source: Xinhua News Agency)