Ambiguous AI crash report did what it shouldn't—leave much to imagination

As the hour struck midnight on Friday, July 12 —just in time to meet the globally prescribed deadline—the Aircraft Accident Investigation Bureau released a loosely worded and unsigned preliminary report examining the AI-171 crash of June 12 that killed 260 people, including 12 crew members.

- Anjuli Bhargava

Social media and the internet exploded with further speculation, with many arguing the much-awaited report invited more questions than answers. Now, with The Wall Street Journal reporting that the captain cut off fuel supply to the switches, citing anonymous sources familiar with the evidence, there are even more questions.

Clearing some air

Aviation industry executives pointed out that the preliminary report did clear the air to an extent, ruling out several initial theories. The possibility of a bird strike leading to dual-engine malfunction was eliminated. The report also rules out pilot fatigue, arguing both pilots had adequate rest. Wind shear, weather and aircraft weight problems also appear ruled out.

Questions were previously raised about aircraft flaps remaining retracted and incorrectly set for takeoff, but experts say this might have been a consequence of dual engine failure. The aircraft's landing gear also remained deployed throughout the short flight, while on a 787, wheels are normally withdrawn immediately after takeoff.

The report states that fuel loss led to engine malfunctions, caused by fuel control levers “transitioning” from run to cutoff position within one second of each other. This is clearly the main cause since both engines lost power once fuel supply was cut. The report is silent on how this happened, although it paraphrases an interaction between pilots to suggest manual error may have been responsible. The WSJ report now identifies the captain as the person who allegedly cut off fuel. India's aviation regulator is yet to respond.

When each second counts

Even after the preliminary report became public, a theory gained ground that the crash might have been deliberate pilot suicide, of which there have been more cases than most readers would be aware. But senior commanders and experts point to important lacunae with this theory.