India, July 13 -- The Aircraft Accident Investigation Bureau (AAIB)'s preliminary report has clearly identified the cause of the accident: Fuel control switches on Air India Flight 171 moved to "cutoff" position one second apart during take-off, starving both engines and causing 260 deaths in what is the deadliest aviation incident in the country in decades. The question is: How? Was the error human, mechanical, or caused by software?

The findings carry global significance because this represents the first fatal accident involving Boeing's 787 Dreamliner in 14 years of commercial service. While the report is silent on who, or what, caused the error, the exchange between pilots paraphrased in it - one asks the other why he moved the switc...