The harsh criticism of the preliminary report on the accident of the Air India plane in which 260 people died

Although the AAIB has led research, US interests are also represented, since Boeing, manufacturer of the aircraft, and GE Aerospace, engine manufacturer, are Americans.

The report does not offer conclusions about the cause of the accident. However, it has generated considerable controversy.

In its story of the injured flight, the AAIB states that two fuel cut switches moved from the “operation” position to that of “cut” seconds after takeoff.

This deprived the engines of fuel and caused a loss of thrust. Although the flight recorder data shows that the engines later restarted, it was too late to avoid the accident.

These switches are usually only used to light the engines before a flight and turn them off later. They have a blocking mechanism, which means that you should pull it before turning them, in a system designed to avoid accidental deployment.

The report also indicates that one pilot asks the other “why did you disconnect it?”, While his partner replied that “he did not.”

However, it does not provide any direct transcription of the conversation, which would have been captured by the cabin's voice recorder. Nor does it identify which pilot asked the question.

It should be remembered that preliminary reports do not intend to offer a complete vision of what happened or draw definitive conclusions. Its objective is to be a factual summary of the information obtained in the early stages of what could be an extensive investigation.

The research authority also does not have the obligation to make public their preliminary reports.

The information published so far has led several commentators to affirm, both in the media and online, that the accident was the result of a deliberate and intentional action of one of the pilots.

This opinion has caused an angry response from the Association of Commercial Pilots of India, which warned that “invoking such a serious accusation based on incomplete or preliminary information is not only irresponsible, but also deeply insensitive towards the people and families involved.”

He added that “casually suggesting the suicide of a pilot without verified evidence constitutes a serious violation of journalistic ethics.”

In a memo aimed at staff, the executive director of Air India expressed a similar position. Campbell Wilson warned against the extraction of “premature conclusions.”

Since the publication of the report, the BBC has spoken with various people in the industry, including pilots, accidents and engineers. While theories about what happened vary widely, the predominant opinion is that important information is currently missing.

“They have told us what they want us to know at this time and have hidden us what they do not want us to know,” said a pilot, who asked not to be identified. “It is not a full report.”

One of the main criticism is the lack of a transcription of the voice recorder of the cabin, which would allow contextualizing the alleged conversation between the pilots about the fuel cutting switches.

Bjorn Fehrm, an aeronautical analyst of the consultant Leeham Company, described this “totally unacceptable.” “They have all these technical details. Then there is the reference to dialogue, but it is not even said who speaks,” he said.

Fehrm also worries that there was no reference to what happened in the cabin between the change of the operating switches to the off and the readjustment of the first switch to turn on the first engine 10 seconds later.

“It's someone trying to hide something,” he said.

Meanwhile, an engineering source said that the report was “very selective” and did not contain detailed information about the activity of the engines immediately before operating the switches.

The document does indicate that the engine speed began to decrease from the takeoff values “when the fuel supply is cut.”

This, they explained, it is important, since moving the switches to the cutting position and vice versa is something that a pilot would be trained to do if he needed to restart an engine that was already losing power.

Tim Atkinson, aviation consultant and former air accident researcher in the United Kingdom, declared: “It is very disappointing to read a report that, although it provides some relevant data, leaves many more questions.”

Another element of the report that has generated controversy is the reference to a safety bulletin, known as the Special Information Bulletin on Aircraft, published by the Federal United States Aviation Administration (FAA) in 2018.

This was used to alert the aeronautical community that the operators of some Boeing 737 models had reported cases in which the fuel cutting switches came from the factory with the deactivated block, which could have allowed the switch to be accidentally operated.

At that time, FAA described it as a “aircraft problem”, but said it was not an “insecure condition” that required a mandatory action through the so -called aircraft directive.

Operators of several BOEING models equipped with similar switches were recommended, including 787, to perform simple inspections.

The research report indicates that Air India did not carry out such inspections, which generated speculations that the accident could have been caused by defective switches that were accidentally operated.

However, in an internal note seen by the BBC, FAA has reiterated its conviction that the problem did not compromise security.

Engineering sources have also indicated that the report indicates that the throttle control module of the injured plane was replaced twice, the most recent two years before the accident. This would also have involved replacing the cutting switches.

According to Bjorn Fem, by Leeham Company, the reference to the FAA council contained in the report was “totally irrelevant” in the context of the accident.

However, the General Directorate of Civil Aviation of India has asked the operators of all aircraft covered by the original FAA newsletter to carry out inspections before July 21.

For the former Tim Atkinson accidents, the vagueness of the report could have been deliberate, in order to suggest an explanation of the accident, avoiding being too explicit. “The worst reports are those who are written to read 'between the lines', and if that is what we have here, the researchers do not do justice,” he said.

Meanwhile, those looking for firm answers about what happened on flight 171 could have to wait.

International protocols stipulate that the final report must be published within one year after the accident. However, in practice, it can take much more.

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