Preliminary report gives ‘greater clarity’ and raises ‘additional questions’; don’t draw any conclusion yet as AI 171 crash probe far from over: Air India CEO to staff

“It (preliminary report) also triggered a new round of speculation in the media. Indeed, over the past 30 days, we’ve seen an ongoing cycle of theories, allegations, rumours and sensational headlines, many of which have later been disproven. Instead of focusing on such interpretations, I suggest we note that the Preliminary Report found no mechanical or maintenance issues with the aircraft or engines, and that all mandatory maintenance tasks had been completed,” Wilson said.

“There was no issue with the quality of fuel and no abnormality with the take-off roll. The pilots had passed their mandatory pre-flight breathalyser and there were no observations pertaining to their medical status,” the Air India CEO added.

The doomed aircraft was operating flight AI 171 from Ahmedabad to London Gatwick, and crashed moments after take-off, killing 260 people—241 of the 242 people on board and 19 on ground. It was the worst aviation disaster involving an Indian airline in four decades, and globally the first-ever fatal crash of Boeing’s latest-generation wide-body aircraft—the 787 Dreamliner.

The preliminary investigation report released early Saturday by India’s Aircraft Accident Investigation Bureau (AAIB) has zeroed in on the probable primary trigger of the accident—the engines being starved of fuel with the transitioning of the fuel control switches from ‘RUN’ to ‘CUTOFF’ position within a second of each other moments after lift-off. From the cockpit voice recorder data, the report notes that one of the pilots asked the other why he cut off the fuel, to which the other pilot responded saying he did not. The report just says the engine fuel control switches that allow and cut fuel flow to the plane’s engines transitioned from RUN to CUTOFF. It does not state these were moved by either of the pilots.

According to experts, the investigators should now focus on unearthing the cause behind the transitioning of the fuel control switches, which are used to allow and cut fuel supply to the engines. There is considerable speculation on whether the switches were flicked by one of the pilots—inadvertently or otherwise—or whether the transition signal to the system was due to any technical, mechanical, or software issue. The report did not issue any recommendation to other operators of the Boeing 787-8 aircraft and its GE engines, suggesting that at this stage, the investigators do not have a reason to believe that there was any issue with the plane or its engines.

“The Preliminary Report identified no cause nor made any recommendations, so I urge everyone to avoid drawing premature conclusions as the investigation is far from over. We will continue to co-operate with the investigators to ensure they have everything they need to conduct a thorough and comprehensive enquiry,” Wilson said.

He also reiterated that “out of an abundance of caution and under the oversight of the DGCA”, every Boeing 787 aircraft operating in Air India’s fleet was checked within days of the accident, and all were found fit for service. The airline continues to perform all necessary checks, and will fully comply with any additional checks that the country’s aviation authorities may suggest.

“Until a final report or cause is tabled there will no doubt be new rounds of speculation and more sensational headlines. We must nevertheless remain focused on our task and be true to the values that have powered Air India’s transformation journey over the past three years – integrity, excellence, customer focus, innovation and teamwork. Let us not be diverted from what are our top priorities: standing by the bereaved and those injured, working together as a team, and delivering a safe and reliable air travel experience to our customers around the world,” Wilson said.

An aircraft is an extremely sophisticated and complex machine, and detailed and painstaking investigations are required to ascertain the exact cause or combination of causes behind an accident. The odds that an aviation accident has a single trigger are rare; there could be many, or one leading to another. The AAIB is expected to release the final probe report within a year of the crash, as per international guidelines.