The footage showed the widebody aircraft taking off down a runway in the western Indian city of Ahmedabad, but shortly after rotation, it suddenly lost altitude and crashed into a residential area, sparking all sorts of speculation about what may have caused the crash that killed 260 people. Since then, Indian authorities have remained largely silent—until now.

A newly released preliminary report may finally shed light on what went wrong. Spoiler alert: it's great news for Boeing. Early findings suggest the mid-air disaster was not due to a mechanical flaw in the engines, but likely the result of human error.

On Saturday, India's Air Accident Investigation Bureau released a report revealing that the fuel control switches on the Boeing 787 were set to "cutoff" just seconds after takeoff, explaining why the widebody jet failed to gain sufficient lift after rotation, as thrust could not be produced with Jet A fuel supply cut off. 

"The aircraft achieved the maximum recorded airspeed of 180 Knots IAS at about 08:08:42 UTC and immediately thereafter, the Engine 1 and Engine 2 fuel cutoff switches transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec. The Engine N1 and N2 began to decrease from their takeoff values as the fuel supply to the engines was cut off," the report read. 

The report continued, "In the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff. The other pilot responded that he did not do so."

By the time the one pilot realized the fuel had been cut off and flipped the switches back to "run," it was too late. Although the engines began relight sequences, the aircraft had already reached its peak speed of 180 knots at just a few hundred feet of altitude—leaving no time for trust recovery. 

More details from the report:

As perthe EAFR, the Engine 1 fuel cutoff switch transitioned from CUTOFF to RUN at about 08:08:52 UTC. The APU Inlet Door began opening at about 08:08:54 UTC, consistent with the APU Auto Start logic. Thereafter at 08:08:56 UTC the Engine 2 fuel cutoff switch also transitions from CUTOFF to RUN. When fuel control switches are moved from CUTOFF to RUN while the aircraft is inflight, each engines full authority dual engine control (FADEC) automatically manages a relight and thrust recoverysequence of ignition and fuel introduction.