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.

In the cockpit voice recording, one of the pilots is heard asking the other why he "did the cut-off", the other pilot replied that he didn't.

The AAIB report ruled out pilot intoxication, bird strikes, or fuel contamination as contributing factors. Investigators have recovered critical components for further analysis, and both the US National Transportation Safety Board (NTSB) and the UK government are involved.