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.

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

A preliminary report into the Air India crash that killed 260 people last month showed that seconds after taking off, the plane's engines fuel cutoff switches almost simultaneously flipped from run to cutoff,