Vlucht MH370 Malaysia Airlines - diep in de oceaan #36

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Op woensdag 26 maart 2014 15:19 schreef El_Matador het volgende:

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Met het nieuws dat zelfs Australie geen werkende ROV meer heeft en die kist zo'n 1 km dieper ligt in een stuk nirmandszee, denk nog wel langer.

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Missing Malaysia Airlines flight: why the black box locator could be useless

The US Navy announced plans this week to move a "black box locator" to Perth in case debris from Malaysia Airlines Flight 370 is found in the southern Indian Ocean. But a word of caution: the black box locator faces logistical nightmares that prevented it from being effective in other similar searches in the past. Authorities, in other words, may learn where the flight went down - but they'll have a harder time finding the device capable of explaining why.

The high-tech system on the way to Perth is known, in military-speak, as the Towed Ping Locator 25. Like its predecessors, the system uses a high-powered underwater microphone known as a hydrophone to search for acoustic "pings" coming from beacons mounted on the flight data recorder and cockpit voice recorder in a downed aircraft. They're commonly known as "black boxes'', although they're usually orange. The ping locator, made by the US company Phoenix International, is about 75 centimetres long and weighs 30 kilograms. It closely resembles a miniature torpedo, complete with fins, and is pulled on a long underwater cable behind a ship. It can detect pings from up to 6000 metres under the sea.

Bill Lawson, who oversees the ping locator program for Phoenix International, said that if the beacons on the downed plane's black boxes are still transmitting, his equipment will find them. Towed ping locators have found numerous aircraft in the past, including the downed Adam Air Flight 574, which crashed on January 1, 2007, while flying between the Indonesian cities of Surabaya and Manado, killing all 102 people on board. After the Indonesian government asked the United States for help, the US Navy found it at a depth of between 1500 and 1900 metres. The current version was first fielded in 2010. One year later, it managed to find a Marine Corps AV-8B Harrier that crashed in the Gulf of Aden near Oman in 2011 shortly after takeoff.

Even if the locator sent to Perth is used perfectly, however, it is by no means certain that it will be able to do the job. Consider the case of Air France Flight 447. It crashed off the northeast coast of Brazil on June 1, 2009, killing all 216 passengers and 12 air crew members. The US Navy provided two pinger locators by Phoenix International, but they were towed through the search area for about 30 days without any success. At that point, the first phase of the search was called off because the battery life on the black box transponders was all but certainly dead. It took another two years for the recorders to be recovered, and it occurred only after the bulk of the wreckage was found by robot submarines in April 2011.

"They found that the pingers were damaged and unoperational," Lawson said - meaning the Navy's black box locator wouldn't have worked.