One of the two flight recorders from Air France flight 447. (Charles Platiau/Reuters)

The recordings showed that the plane, which was flying from Rio de Janeiro to Paris, stalled before descending from 38,000 feet into the Atlantic, the Associated Press reports. The descent lasted 3 minutes and 30 seconds. France’s Bureau of Investigation and Analysis (BEA) reported that the captain was taking a routine rest and was not in the cockpit when the emergency began.

(The full report can be read here.)

While the cause of the crash was not explicitly explained in the report, air accident investigation agency director Jean-Paul Troadec said a “combination” of faulty sensors, human error and other mechanical issues were possibly to blame. The co-pilots were getting inconsistent speed readings before the plane crashed, according to the report.

“It seems they did not feel more movements and turbulence that you generally feel in storms," Jean-Baptiste Audousset, president of a victims’ solidarity association, told the AP. “So, we think that until impact they did not realize the situation, which for the family is what they want to hear — they did not suffer.”

Both black boxes were located this May. A full report on the crash is expected for next year.