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

Authorities released a preliminary report on the Air India crash, following an investigation. The London-bound flight from Ahmedabad crashed minutes into the June 12 flight. Only one passenger of the 242 passengers and flight crew survived.

By Aditya Kalra, Allison Lampert and Abhijith Ganapavaram NEW DELHI (Reuters) -A preliminary report depicted confusion in the cockpit shortly before an Air India jetliner crashed and killed 260 people last month,