Three weeks after an Air India Boeing 787 crashed, investigators are still piecing together what went wrong. In the meantime, aviation safety experts have begun to narrow their thinking.

Spooked by the Air India plane last month that crashed seconds after departing from the Ahmedabad airport, private jet owners who have aircraft registered at the facility are doubling down on safety precautions.

The official crash investigation is being led by Indian authorities, who currently hold exclusive access to the black box data and cockpit voice recordings recovered from the crash site. The final government report is still pending,