MH370 Australia yesterday detected two more ping signals in its search for Flight MH370 in the Indian Ocean, bringing the total to four transmissions that are very likely beamed from a plane black box underwater.
According to the Joint Agency Coordination Centre (JACC), the first two detections were made last Saturday, April 5, at 4.45pm and 9.27pm Perth time, which is the same as Malaysia. Contact was lost on Monday but re-established on Tuesday in the same area, at 4.27pm and 10.17pm.
JACC chief Angus Houston ( right ) said analysis on the ping data showed that they were "not of natural origin but likely sourced from specific electronic equipment consistent with the specifications and descriptions of a flight data recorder".
Analysis of the first two transmissions were at intervals of 1.106 seconds, which made it consistent with the signals expected from a plane's black box.
Data from first two pings analysed at the Australian Joint Acoustic Analysis Centre (AJACC) at HMAS Albatross in New South Wales, determined that the signals were “stable, distinct and clear” at a frequency of 33.3kilohertz.
No commitment missing aircraft found
Houston said he wanted to be very careful about misinforming the families of the MH370 passengers.
He would therefore not make any commitment that the team has found the missing Boeing 777, reiterating that it will only do so once the wreckage can be sighted by a sonar and video-equipped automatic underwater vehicle (AUV), such as the Bluefin-21.
"The only thing we have got at the moment is detection of transmissions. We have no idea what is under the water.
"Once there is no more hope of picking up any more transmissions, we will put the AUV down," Houston told reporters at the Dumas House in West Perth.
All four pings were picked up by the Australian Defence Vessel (ADV) Ocean Shield at the northern end of the defined underwater search area of about 75,423 square kilometres.
The latest two pings on Tuesday lasted 5 minutes 32 seconds and 7 minutes respectively.
Houston said that compared with the earlier two signals last Saturday, the pings were getting weaker but JACC has decided that it won't deploy an underwater drone to investigate until there are absolutely no more pings.
"There is no second chance. The signal we picked up recently is much weaker. Either we are a long way away or, more likely, the (black box) battery is starting to fade.
"We need to make hay while the sun shines... to get all the data we can," Houston said, explaining why the JACC could not deploy an AUV today.
He added that it was likely the torpedo-like Bluefin-21 AUV could be sent deep underwater to scour the ocean floor in "matter of days."
The Chinese ship Haixun 01 and the HMS Echo , which are scouring the southern part of the underwater area, have not picked up any further signals since last Saturday.
To a question, Houston said that none of the debris found in the vicinity so far could be connected to Flight MH370.
Therefore, the eight-nation team JACC is not searching other areas at the moment and in fact, has significantly reduced the search area over last two days - focusing on where the four pings were detected.
"No, we are not covering more territory. One of the important things about this search is a noiseless environment. Already, the Ocean Shield is minimising noise, with only two thrusters at back of the vessel. If we have other ships there, we may end up with noisy environment," he said.
He said while he could sympathise with the people's urgent need to know, since the MH370 has gone missing for 33 days, the JACC decided that this was the best option.
"Searching underwater is labourious. The more we can do on surface with towed pinger locators to fix location of the transmission, the less work we have to do below the surface," Houston said, adding Ocean Shield can cover a search area six times larger than an AUV alone.
