The black box was freed from beneath the wing early Tuesday from a depth of about 100 feet, Indonesian Transportation Ministry official Tonny Budiono told The Associated Press.
Divers on Monday retrieved the first black box containing the flight's data recorder from the floor of the Java Sea two weeks after the plane crashed, killing the 162 people on board.
The black boxes will be taken to Jakarta, where they will be analyzed, according to The Associated Press. All discussions between the captain and co-pilot during the 42-minute flight should be available, though it may take up to two weeks to read out.
"This is a very complex accident and we're not going to get instant answers that are going to take full scope of it, put it out on the table, for some time,” John Nance, a retired commercial pilot and ABC News aviation consultant, said. “But we may get a quick indication here of at least what it isn't.”