A preliminary assessment in last month’s disaster focusing on fuel being cut to both engines only deepened the mystery for people grieving loved ones.

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 troubling cockpit dialogue revealed in a preliminary report into the June 12 crash of Air India flight 171 – which killed all but one of the 242 passengers on board – is likely to haunt investigators,