Four pings no longer believed to be from MH370’s black box, says US official

Four acoustic transmissions that have been the focus of the search for missing Malaysia Airlines flight 370 are no longer believed to have come from the plane's black box, a US official said today.

The US Navy's deputy director of ocean engineering Michael Dean told CNN there was now broad agreement that they came from some other man-made source unrelated to the jet that disappeared on March 8 carrying 239 people.
Speaking to CNN, Dean said that if the pings had come from the recorders, searchers would have found them.
Dean added in the CNN report that other countries involved in the search for MH370 had come to the same conclusions.
"Our best theory at this point is that (the pings were) likely some sound produced by the ship... or within the electronics of the Towed Pinger Locator," the CNN report quoted Dean as saying.
"Always your fear any time you put electronic equipment in the water is that if any water gets in and grounds or shorts something out, that you could start producing sound."
Dean added that while it was not possible to absolutely exclude the theory that the pings had come from the flight's black boxes, there was no evidence now to suggest that they had.
The acknowledgement came as searchers concluded the first phase of their effort in which they scanned 239 square miles of the ocean floor without finding any trace of wreckage.
The acoustic transmissions played a key role in the search for MH370, the most extensive and expensive effort in aviation history. Authorities had earlier said that technology greatly increased the chances of success while search officials expressed "cautious optimism" in the pings when they were discovered last month.
However, experts had warned that crash damage or deep ocean pressure could alter the pinger frequency, a caution which stemmed from the pings' 33.3 kHz frequency – slightly lower than the design frequency of 37.5 kHz. They also raised concerns regarding the ping detection sites which were miles apart, noting that sounds can travel far, and even echo, in underwater environments.
In the CNN report, Dean said officials were also concerned because although pings had been detected twice on April 5, searchers had difficulty reacquiring the pings the next day.
Yesterday, British satellite company Inmarsat defended the accuracy of its data, saying that it had been checked by other parties as well.
Inmarsat vice-president of satellite operations Mark Dickinson had told CNN that many other parties who had done the same work with the same numbers had agreed on the data's accuracy.
"We have also compared the data here with data pertaining to other flights around the same time as well as the data from previous flights by the same aircraft," Dickinson added.
According to feedback received by CNN, families of passengers on board MH370 agree that the data should have been released sooner, but are not of one mind on the impact it has on current investigations or on the search for the missing aircraft.
CNN also reported that other families, especially those in Malaysia, said they do not care for the data and whether it is 100% accurate or not, wanting only some kind of debris to enable closure over the traumatic incident.
Flight MH370 was carrying 227 passengers and 12 crew when it vanished on March 8. Although authorities have not ruled out mechanical failure, they said that the loss of communication suggests the plane was deliberately diverted from its scheduled route from Kuala Lumpur to Beijing. – May 29, 2014.