Once the wreckage of missing flight MH370 is found, rescuers will launch an unmanned underwater operation to locate the black box.
On Monday, Angus Houston, head of the Australian agency coordinating the search for Malaysia Airlines Flight MH370, said that they had come across a “most promising lead” after two signals were detected off Australia’s northwest coast.
However, data recorders on the black boxes only transmit for 30 days after a crash – meaning rescuers have only a few days left to find it.
The device on the missing plane that makes those signals is made by US company Dukane Seacom. Its director, Chris Portale, told Channel 4 News: “We’ve got probably five days of a good solid ping, but as the battery wears on, the signal won’t just stop, it will slowly degrade.
“So you’ll still be able to detect the ping, but it will be more difficult to detect.”
If the pings are confirmed and the wreckage is found, the difficult task of reaching and recovering the black box in ocean depths ranging from 13,100-16,400 feet would begin.
The black box contains the flight data recorders and cockpit voice recorders, which could help investigators determine what happened to the flight.
These recorders are painted bright orange with white reflective strips on the sides and contain crash-protected tape or memory modules where the data is stored.
David Mearns, director of Blue Water Recoveries, told Channel 4 News: “As soon as the wreckage is found teams will send autonomous underwater vehicles (AUVs) to search for the black box.”
AUVs are programmable, robotic, unmanned submarine vehicles that, depending on their design, can drift, drive, or glide through the ocean without real-time control by human operators.
They carry sensors to navigate and map features of the wreckage until the black box is located. An AUV located the Air France Flight 447 in 2009 after it crashed in the southern Atlantic Ocean in 2011.
Once it finds the black box, a remotely operated vehicle (ROV) will the begin a salvage operation.
The ROV places the black box into a special water-filled container before it can be lifted out of the ocean.
According to USA Today, once the black box has been salvaged, engineers carefully unscrew the containers to locate a computer board with chips that store the plane’s recorders. The recorders are dried slowly and deliberately in a vacuum oven.
The light data recorder is then downloaded and converted into numbers, which are used to create animation of the plane’s final flight.
The voice recorder, on the other hand, captures four channels: the captain, the co-pilot, a general cockpit microphone and, potentially, an extra pilot.
A team investigators will then study the recording and develop a transcript. By law, the recordings are never released publicly, but transcripts are released by the time the authorities meets to decide what probably caused a crash.