Fuel control switches for the engines of an Air India flight that crashed last month were moved from the “run” to the “cutoff” position moments before impact, starving both engines of fuel, a preliminary investigation report said early Saturday.

An official report on the world’s deadliest aviation accident in a decade, seen by CNN, has answered one key question – but raised others.

The US Federal Aviation Administration has issued a notice to its international counterparts that fuel control switches in Boeing aeroplanes like the Dreamliner involved in last month’s fatal Air India crash do not pose a safety issue.