Unmanned Submarine To Search For Flight 370

The Bluefin-21 is an unmanned submarine that uses sonar to map the sea floor. The submarine will now be used in place of the towed pinger locator.

Unmanned Submarine To Search For Flight 370
Bluefin Robotics

​For the first time in the five-week hunt for Flight 370, the search is moving to the ocean floor. (Via U.S. Navy

“Analysis of the four signals has allowed the provisional definition of a reduced search area on the ocean floor.” (Via Sky News

And that’s where the Bluefin-21 comes in. The mini sub is equipped with side-scan sonar used to make a 3D map of the ocean floor. That technology allows it to create pictures with sound instead of light. (Via Bluefin Robotics) 

"It actually paints a picture line by line over time. So at the end of about 16 hours, it's going to have a whole strip of sea floor that's going to be pasted back together." (Via CNN

The Bluefin will start by searching an area measuring three by five miles. It takes a minimum of 24 hours to complete one mission. Two hours to reach the sea floor, 16 hours to search, two hours to return to the surface, and four hours to upload and analyze the data. (Via Bluefin Robotics / Mierlo

Until now, search teams have resisted using the Bluefin-21 because it takes much longer to search the same area than the towed pinger locator. Bluefin-21 can't relay information in real time and it also can't be used simultaneously with the towed pinger locator.

That's the device attached to the Australian navy ship Ocean Shield. So far, it's picked up four underwater pings thought to have come from the plane's black boxes. (Via U.S. Navy)

And while officials called it their best lead so far, search teams haven’t heard any new pings since April 8 — exactly one month after the Beijing-bound plane disappeared. Officials say it's likely the batteries powering the pings have died by now. (Via BBC & ABC

Ocean Shield also recently spotted an oil slick in the same area where the pings were detected. A sample is being sent to a lab for testing.