The captain of the AirAsia flight QZ8501 that crashed into the Java Sea last year in December was out of his seat as he was conducting some unusual activity while his co-pilot apparently lost control.
According to the Independent, the captain was too late to save the plane by the time he returned, said two people close to the investigation.
They said that investigators were examining the Flight Augmentation Computer (FAC) recovered from the Airbus A320 adding that captain had taken the "very unusual" step of disabling the system.
An A320 pilot, who chose to remain anonymous, said that the FAC can be reset but to cut all power is very unusual.
The Airbus A320 crashed into the Java Sea while it was en route from Indonesia to Singapore on 28 December with 162 people on board.