Earlier today, April 7th, it was announced that a U.S. Navy vessel had confirmed that a "ping" was received by its underwater receiver. What does it mean, and does it guarantee that we've finally put a close to this awful mystery?
When an aircraft as large as the 777 goes down (like Asiana 214), there are dozens of mechanisms that trigger, designed to allow searchers and rescuers to locate the aircraft. In this case, the 777 has many "pingers", or small radios that broadcast weak signals of 37.5 kHz. Designed to broadcast the same signals (about one "ping" per second), the batteries die about 45 days after activation. Luckily, the a Chinese vessel first picked up the signal a few days back, before the weak signals broadcast no more. If that had happened, it is very likely that we would never find closure for MH370.
The pingers, designed to activate when high g levels are detected, are 2km under the Southern Indian Ocean. So all we have to do is send one of our fancy submarines down there and pick up the flight data recorder, right?
Sure, but it will take some time. IF this is the plane, the U.S. (or China) will begin the actual search for the "black" box, which is actually neon orange for good reason. The box could be buried in silt, or sitting right in plain view; we'll just have to wait.
The good news: we may finally have closure. The fate of this flight is almost determined; the families may now understand the truth.
The bad news: don't get excited about finding these recorders just yet. The search for the data recorders could take years. Once we have them, however, we'll finally have the resources to find out why altitude fluctuated, why the radar transponder was switched off, and why a $260,000,000 aircraft disappeared in the technology-rich age of 2014.