The public was made Preliminary report of the Air India flight disaster, in which a Boeing 787-8 Dreamliner crashed on June 12 immediately after taking off from Ahmedabad airport, causing 260 victims and 68 injured. The report summarizes in 15 pages the results of the first investigations conducted byAircraft Accident Investigation Bureau (AAIB), the Indian aviation body, and had already talked about itself since last Friday when the Wall Street Journal He anticipated some salient points before the public spread of the relationship.
The chronological reconstruction of the Air India disaster: what happened
The Boeing 787-8 Dreaminliner has normally taken off at 08:08:39 UTC (13:08:39 rooms). Just 3 seconds later, at 08:08:42the two switches for the valves that regulate the flow of fuel in the engines have been deactivated over a second, first the 1 engine (the left one) and immediately after the 2 engine. At that moment the plane was traveling a 180 knots (about 330 km/h). The Flight Data Recorder (the “black box” of the plane) recorded the passage of the two switches from the RUN mode (Fuel flow) to the Cutoff mode (interrupted flow). The two switches They cannot be activated or deactivated erroneously Because they have a spring lock system that requires that they are raised from their rest position before being moved. In addition, they are found in a point of the dashboard where the hands of the pilots do not end spontaneously.
And here comes the most important moment of the whole report, which reports: “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». In Italian: «In the recording of the items in the piloting cabin One of the two drivers are heard to ask the other because he turned off the switches. The other pilot replied that he did not do it».
In the meantime, both engines descend under the minimum threshold and the plane loses push. As a consequence to 08:08:47 The automatically activates the RAM Air Turbine (RAT), whose purpose is not generating portion but providing electricity in the case of sudden loss of power of the engines.
They pass 5 seconds before at 08:08:52 The engine switch 1 is reactivated, passing from Cutoff to Run. The same takes place 4 seconds later for the 2 engine, at 08:08:56. The engines try to resume thrust: the left one succeeds, but the other will never come to arrest the deceleration. The latter important element is confirmed by the fact that the two switches were found in the Run position. The Boeing 787-8 Dreamliner therefore cannot recover altitude.
To 08:09:05 one of the two drivers transmits a Maydayrepeated three times, to the control tower. It is the latest communication recorded before the crash, which occurred only a few seconds later.
What are the questions still unresolved
The central moment of the report is the exchange of jokes between the two pilots. The report, however, is quite vague, not reporting the complete transcription of the items in the cabin (normal fact, for a preliminary report). We therefore do not know who of the two asked the other to have turned off the engines and who of the two replied.
We know that the commander, Sumet Sabharwal56 years old, was of great experience having accumulated 15,638 flight hours of which 8596 on Boeing 787-8, while the first officer Clive Kunder32 years old, had a much more modest experience with 3403 flight hours of which 1128 on 787-8. The latter had the role of Pilot Flyingthat is, it was materially to the commands of the aircraft, while the first officer dealt with Pilot Monitoringthat is, monitor the tools and communicate with the control tower. Both were suitable on the fly and had completed all the necessary exams.
The answer “I did not do it (remove the flow of fuel to the engines)” does not allow us to understand if there has been a third person in the cabin, if it were a lie or if the gesture has never actually been made. In this regard, the report quotes a special bulletin of the US Federal Aviation Association (FAA) of 17 December 2018 in which cases are mentioned in which the switches have spontaneously turned off in some models of 737, which have the same dashboard as 787-8. However, no defects or malfunctions have been reported to the switches of the plane, whose dashboard was replaced in 2019 and 2023, never for issues related to switches.
In about a year the final report On the disaster, which unlike this preliminary relationship – which, we remember, has the task of collecting the evidence available within the first month of the accident – will try to shed light on causes of what happened. For now, the doubt remains if it was an technical problem or an intentional gesture. Certainly, if as it would seem one of the two pilots has turned off the engines intentionally, It is possible that we will never find out why he did it.
