A team of autonomous underwater robots played a crucial role in locating debris and missing bodies from Air France Flight 447, which crashed into the Atlantic Ocean almost two years ago with 216 passengers and 12 crew members on board while traveling from Rio de Janeiro to Paris.
Three robots, called REMUS 6000s, took to the water off Suape, Brazil, on March 25 with the goal of searching the seafloor until the wreckage was found. This was the fourth search mission in two years by investigators to locate the flight.
The REMUS 6000s, developed by researchers at the Woods Hole Oceanographic Institution, can dive as deep as 6,000 feet and can remain underwater for 20 hours at a time.
After just a week into the planned three-month search, one of the robots, or autonomous underwater vehicles (AUVs), caught a glimpse of debris, which was later confirmed as parts of the missing plane. Divers later discovered bodies from the crash that had been given up for lost.
The debris from the flight was found about 600 miles off the coast of Brazil, at a site no farther than six miles from the last-known location of Air France Flight 447, according to the New York Times.
About 13 feet in length and 28 inches in diameter, each torpedo-shaped autonomous vehicle emits a sonar beam that scans up to 600 meters on either side as it travels along the seafloor. The robots are programmed to move in long overlapping lanes — a process the team dubbed “mowing the lawn” —and to use their sonar to create abroad overview of the landscape. The bots can return to areas of interest for a closer look using high-resolution cameras located on the bots’ bellies.
One of the bots was scanning a swath of Atlantic seafloor two weeks ago when it stumbled across metal debris strewn across the ocean’s bottom.
“That’s when we recognized the parts of Air France 447,” David Gallo, director of special projects at WHOI, told TechNewsDaily.
The images brought back by a second AUV showed the fuselage, engine and landing gear as well as a sonar map of some of the crash area.
Next up will be locating the rest of the plane, including the flight data recorders, which hopefully will piece together what happened on June 1, 2009.
“Now that we’ve found the plane, we’re in a different mode,” Gallo said. “Now we’re in a mapping mode, we’ve come down lower and we’re doing intense sonar and camera mapping of the debris field of the wreck area so that we can produce essentially a Google Earth-type image of that debris field so we know where everything is in that debris field.”
Gallo expects this phase of the project to take about three to four days.
The plane crashed along the eastern flank of the Atlantic’s mid-ocean ridge, which is “some of the most rugged terrain on the planet,” Gallo said. “There’s ridges and valleys and troughs — much more rugged than the Alps."