Flight 370: How the BlueFin-21 Sonar Sub Works

The Wall Street Journal
April 14, 2014 AT 6:38 PM
It takes two hours for the Bluefin-21 underwater vehicle to reach the seabed to search for remnants of Malaysia Airlines Flight 370. Why do authorities think it's now the best hope for finding the missing plane? WSJ's Jason Bellini has #TheShortAnswer.