Indonesian investigators said the cockpit recording from the crashed Lion Air jet showed the pilots searching a manual to try to find why the plane kept lurching downwards.
The details were revealed at a press conference, where an investigator said the recording captured a "panic" in the cockpit in the last 20 seconds of the flight.
They are looking into how a computer ordered the plane to dive in response to data from a faulty sensor and whether the pilots had enough training to respond to the emergency.
The investigation has taken on new urgency after a second 737 MAX 8 crash at Ethiopian Airlines last week killed 157 people and led to the global grounding of the model.

Israeli airforce pounds Beirut, Lebanon death toll rises
US releases Epstein-related FBI interviews mentioning Trump
Hezbollah warns Israeli residents to evacuate towns near border
US House rejects war powers resolution, backs Trump on Iran war
Saudi Arabia, Qatar, Kuwait intercept drones targeting territory
GCC and EU ministers urge immediate halt to Iranian attacks
India's tech state Karnataka bans social media for children under 16
Indonesia says it will withdraw from Board of Peace if it does not benefit Palestinians
