As theories are spinning for Air India, key details remain unknown

While the preliminary report on what caused the loss of flight to the Air India 171 last month, it also gave some answers, it also caused a wave of speculation about its cause.

The Boeing 787 Dreamliner crashed into a building less than a minute after a departure from Ahmedabad to West India on the way to London, killing 241 people on board, along with 19 on the ground. One passenger survived.

The information contained in the Air accident investigation report in India, the first official story about what happened, raised questions about the role of pilots.

However, experts in the aviation industry are the researchers very elective in what they chose to say.

According to the international protocols, the state, a leading investigation of air accidents, aims to issue a preliminary report within 30 days. The 15 -page document published by the Investigation Bureau of Accidents in India (Aaib) on Saturday fulfills this requirement.

Although AAIB is leading the investigation, US interests are also presented as Boeing, the airplane manufacturer and GE Aerospace, the engine manufacturer is American.

The report does not draw any conclusions about the cause of the accident. Nevertheless, it caused a significant dispute.

In his AAIB accident account, two fuel switches have been moved from the “running” to the “cut” position seconds after the departure.

This deprived the fuel engines and made them lose the thrust. Although the flight recorder shows that the engines were subsequently restarted, it is now late to prevent the crash.

These switches are usually used only to turn engines on before flight and turn off afterwards. They have a locking mechanism, which means that they must be pulled before they are turned, a system designed to prevent accidental implementation.

The report also states that one pilot asks the other “why he cut off” while his colleague “replied that he had not done it.”

However, he does not provide a direct copy of the conversation that would be raised by the voice recorder of the cockpit (CVR). Nor does it identify which pilot asked the question.

It is worth remembering that preliminary reports are not intended to offer a complete picture of what happened or to draw firm conclusions. They are intended to be a factual summary of the information obtained in the early stages of what may be a continuous investigation.

The investigating authority is also not obliged to make its preliminary reports public.

The information published so far has encouraged a number of commentators to claim that in the media and online the accident is the result of deliberate and deliberate action by one of the pilots.

This is an opinion that attracted an angry response from the Indian trade pilots Association, which warned that “summoning such a serious claim based on incomplete or preliminary information is not only irresponsible – it is deeply insensitive to people and families.”

He added that “to assume that pilot suicide in the absence of verified evidence is a gross violation of ethical reporting.”

In a staff note, Air India’s CEO hit a similar note. Campbell Wilson warned of “premature conclusions”.

Following the release of the report, the BBC spoke with a number of people in the industry, including pilots, investigative accidents and engineers. While theories about what actually happened, it varies greatly, the dominant opinion is that there is currently no important information.

“We were told things we wanted to know right now and kept what they did not want to know,” explained a pilot who wanted not to be identified. “This is not a complete report.”

One of the main criticisms is the lack of a copy of the voice recorder of the cockpit, which would allow reporting conversation between pilots about the fuel interruption switches to be placed in context.

Bjorn Fehrm, an aeronautical analyzer from Leeham News consultants, said it was “completely unacceptable”.

“They have all these technical details. Then you have this reference to dialogue, but it doesn’t even tell you who is talking,” he said.

Mr Fehrm was also concerned that there was no reference to what happened in the cockpit between the switches, which were transferred from running to cut, and the first switch was pushed back into a position to reduce the first engine 10 seconds later.

“This is someone who is trying to hide something,” he said.

In the meantime, the engineering source said the report was “very electoral” and there was no detailed information about what the engines do just before the switches were turned. The document says that the engine speed has begun to decrease from take -off values “as the supply of fuel to the engines is cut off.”

This was said that it was important – as the transfer of switches to cut and vice versa is something that will be a trained pilot to restart an engine that is already losing power.

Tim Atkinson, an aviation consultant and a former air accident investigator in the UK, said: “It is very disappointing to read a report that provides several noticeable facts leaves many more questions.”

Another element of the report that caused a dispute is a reference to the safety newsletter – known as a special newsletter for flywheeling information – published by the US Federal Aviation Administration (FAA) in 2018.

This was used to warn the aviation community that the operators of some Boeing 737 models report cases where the fuel interruption switches were provided with an off lock function – potentially allows the switch to be turned by accident.

At that time, the FAA described this as “a concern for air fitness”, but said it was “not a safe condition”, which would require mandatory actions through what was known as a flywheeling directive.

Operators of a number of different models of Boeing, equipped with similar switches, including 787s, were advised to carry out simple checks.

The investigation report states that Air India did not carry out these inspections – prompted speculation that the incident may be caused by defective switches that are accidentally reversed.

However, In an internal note observed by the BBCFAA has since repeated his belief that the issue has not compromised safety.

Engineering sources also indicated that the report says the pattern of the crash’s throttle management was replaced twice, most recently two years before the accident. This would include replacement of cutting switches.

According to Björn FECRM of Leeham News, the reference to the FAA tips contained in the report is “completely irrelevant” in the context of the accident.

Nevertheless, the Directorate -General for Civil Aviation has asked the operators of all aircraft covered by the original FAA newsletter to carry out checks by 21 July.

For the former accident researcher Tim Atkinson, the vagueness of the report may have been intentional – to offer an explanation for the crash, while avoiding being too explicit.

“The bigger reports are the ones who have to read” between the lines “, and if that is what we have here, then it has no merit of investigators,” he said.

Meanwhile, those looking for firm answers to what happened at flight 171 may have to wait.

International protocols determine that the final report should be published within a year of the accident. In practice, however, it can take a lot more time than that.