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.
The Towed Ping Locator 25 System can locate downed aircraft at a maximum depth of 6000 metres. Photo: AFP
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.
One of the two black boxes recovered from Air France flight 447, which crashed in 2009. Photo: AP
Malaysian authorities said this week that they now believe MH370 crashed in the Indian Ocean southwest of Perth. The Boeing 777 disappeared on March 8 with 227 passengers and 12 crew members on board after diverting from its planned flight path from Kuala Lumpur in Malaysia to Beijing, China. All on board are believed to be dead.
There are a range of unknowns that will determine whether the ping locator has any more luck finding the Malaysian flight than it did with the Air France one. First, the part of the Indian Ocean where the airline crashed is believed to be as much 7000 metres deep, a potentially major problem given that the ping locator can only operate to depths of about 6000 metres. Second, Navy officials won't start using the device until they have a much more specific sense of where the plane went down. The black box's beacons have a 30- to 40-day battery life, so precious time will be lost while authorities search for debris or other evidence of where the plane crashed. And that's to say nothing of the condition of the black boxes themselves, which - like Air France's downed airliner - may not be transmitting pings following the crash because they are damaged.
"This movement is simply a prudent effort to pre-position equipment and trained personnel closer to the search area so that if debris is found we will be able to respond as quickly as possible since the battery life of the black box's pinger is limited," said Navy Commander Chris Budde, the operations officer for the Navy's 7th Fleet, which has coordinated US involvement in the search.