The "black box" cockpit voice recorder (CVR) from Air France 447 -- the Airbus A330 that disappeared over the Atlantic nearly two years ago -- has been found off the coast of Brazil.
The newly-located CVR is different to the Flight Data Recorder (FDR), which was found on Monday.
The CVR records everything the pilot and co-pilot say, while the FDR stores data taken from the plane's electronic and mechanical systems.
Retrieving the CVR box -- and downloading the recordings -- is one of the most important steps in finding out what happened to AF447.
The flight crashed into the sea on a flight from Rio de Janeiro in Brazil to Paris' Charles de Gaulle airport after through high-altitude thunderstorms.
French Minister of Transport Thierry Mariani told French radio: "We can now hope to find out what truly happened within the next three weeks."
The French Bureau d'Enquêtes et d'Analyses (BEA), which is the equivalent aviation safety body to Australia's ATSB, said that the boxes would be sent to France within a fortnight.
BEA's mission is clear: "The sole objective of the technical investigation is to collect and analyze useful information, to determine the circumstances and the certain or possible causes of the accident or incident and, if necessary, to make safety recommendations in order to prevent future accidents and incidents."
The analysis and recommendations from BEA will likely be adopted by other aviation safety administrations.
Airlines and travellers will be interested in the results too. Over 770 examples of the Airbus A330 plane involved in the accident have been built. Locally, Virgin Australia, Jetstar and Qantas have the aircraft in their fleets.
Asian airlines frequently use the wide-bodied, twin-aisle, twin-engined A330s between Australia and their hubs as well. Malaysia Airlines, for example, will be running its newest A330s on routes to and from Kuala Lumpur.
Preliminary investigations suggested that the pitot tubes (which record airspeed) might have malfunctioned due to icing, leading to incorrect airspeed readings. But that by itself doesn't explain the crash.
The full story may only be known if and when the data can be pulled off the recorders once they reach France.