Preliminary findings indicate that the circuit breakers for the fuel flow to the plane's engines were turned off, according to American assessments that The Wall Street Journal has been informed of.
The circuit breakers are used to start the plane's engines, turn them off or in certain emergency situations reset them.
In normal cases, they should be turned on during a flight. It does not appear how or why they were turned off, if it was a mistake or intentional.
The Indian authority that investigates plane crashes is expected to present its preliminary investigation later on Friday.
The plane from Air India crashed shortly after takeoff from Ahmedabad in northwestern India last month. A total of 279 people died, several of them on the ground, when the plane crashed into a residential area. One passenger miraculously survived.
