Investigators have made a freezing discovery in the preliminary investigation of the Air India Flight 171 crash, which killed 260 people in June.
Just seconds after departure, the 12-year-old Boeing 787 Dreamliner Control Control has moved sharply to the cutting position, starving fuel engines and triggering the overall power loss. The switch to “cut” is a move, which is usually done only after landing.
The voice of the cockpit captures a pilot asking the other why he “made the section”, to which the man replies that he did not. The recording does not clarify who said what. During the take -off, the pilot flew the plane as the captain was watching.
The switches were returned to their normal position in the West, activating automatic engine extraction. During the crash, one engine regains the thrust while the other had religious but has not yet restored power.
The Air India Flight 171 was in the air for less than a minute before colliding into a crowded neighborhood in the western Indian city of Ahmedabad, marking one of the most confusing aviation disasters in India.
Investigators follow the remains and cabins to find out what went wrong after the take -off. The Air India flight climbed to 625 feet in clear weather before losing about 50 seconds, according to the Flightradar24 website.
The preliminary report of the investigation – led by Indian bodies with experts from Boeing, General Electric, Air India, Indian regulators and participants from the US and UK – raises several questions.
Investigators say that lever fuel switches are designed to prevent accidental activation – they must be downloaded to unlock before flipping, a safety function dating from the 1950s. Built for demanding standards, they are very reliable. The protective clamps of the fuses further protect them from accidental irregularities.
“It would be almost impossible to download both one -hand switches, and this makes the random deployment unlikely,” the BBC, based in Canada, which wanted to remain unnamed, told the BBC.
This is what makes the Air India case stand out.
If one of the pilots was responsible for the exclusion of the switches, intentionally or not, he “raises the question: why,” said Sean Prukhnitsky, a former airline researcher and an aviation expert at Ohio State University.
“Was it deliberate or the result of confusion? That seems unlikely as the pilots report anything unusual.
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“In many emergencies on the cockpit, pilots can press the wrong buttons or make wrong selections – but there is no indication of such a situation, nor any discussion, which suggests that the fuel switches are chosen by mistake,” he said.
“This type of mistake usually does not happen without any obvious problem.”
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Peter Gölz, a former managing director of NTSB of the United States, said: “The finding is very disturbing – that the pilot has turned off the fuel switch within seconds after flying.”
“There is probably a lot more on the voice recorder of the cockpit than what is shared. A lonely remark like” Why you cut the switches “is not enough,” he said.
“The new details suggest that someone in the cockpit turned off these valves. The question is who and why? Both switches were off and then restarted within seconds.
“The voice recorder will reveal more: the flying pilot was trying to restart engines or monitoring?”
Investigators believe that the voice recorder of the cockpit – with pilot microphone audio, radio hinges and atmospheric sounds of the cockpit – holds the key to this puzzle.
“They have not yet identified the votes, which is crucial. Usually, when the voice recorder is reviewed, people familiar with the pilots are present to help match votes. At the moment, we still don’t know which pilot turned off the switches and again,” said G -n Guelz.
In short, investigators say that what is needed is a clear voice identification, a complete copy of the cockpit with labeled speakers and a thorough review of all communications from the moment the aircraft was pushed back from the gate to the moment it collapses.
They also say that this emphasizes the need for video recorders on the cockpit, as recommended by NTSB. The view above the shoulder would show whose hand it was off.
Before getting on flight 171, both the pilots and the crew passed respiratory tests and were released from the suitability to fly, the report said. The Mumbai -based pilots arrived in Ahmedabad the day before the flight and had an adequate vacation.
But investigators are also interfering with what they describe is an interesting point in the report.
It says that in December 2018, the US Federal Aviation Administration issued a special airport information newsletter (SAIB), stressing that some Boeing 737 fuel control switches were installed with an off locking feature.
Although the question is noted, it is not considered a dangerous condition requiring a directive of airworthiness (AD) – a legally enforceable regulation to correct dangerous conditions in a product.
The same design of the switch is used on the Boeing 787-8 Boeing 787-8 aircraft, including Air India’s VT-Annb, which crashed. Since SAIB was consultative, Air India did not carry out the recommended checks.
Air India Flight 171 crashed into a crowded neighborhood in Ahmedabad [Getty Images]
G -n pruchnicki said he was wondering if there was a problem with fuel control switches.
“What does this do [bit in the report] Exactly sublimate? Does this mean that with one flip this switch can turn off the engine and cut the fuel supply? When the locking feature is turned off, what exactly happens? Can the switch simply turn to off and turn off the engine? If so, this is a really serious problem. If not, that should also be explained, “he said.
Others, however, are not convinced that this is a key problem.
“I haven’t heard of what seems to be a low profile FAA. Nor have I heard complaints [about the fuel switches] From pilots – who usually talk quickly. It is worth exploring as it is mentioned, but it may just be a distraction, “said G -n Gaelz.
Captain Kishore Chinta, a former investigator at the Indian Accident Investigation Bureau (AAIB), wonders if the switches are stumbling because of a problem with the electronic airplane control.
“Can fuel switch switches be activated electronically from the electronic airplane control without a pilot movement? If the fuel switch switches stumble electronically, then this is a cause for concern,” he told the BBC.
The report states that the fuel samples from the charging tanks were “satisfactory”. Experts have proposed fuel contamination as possible as a possible cause of double engine damage. In particular, no Boeing 787 advice has been issued or its GENX-1B engines, and so far, mechanical damage is excluded in anticipation of a further investigation.
It is also said that the airplane airplane (rat) was located – a clear sign of a major damage to the system – and the landing facilities were found in a “down position” or not harvested.
The rat, a small propeller that extends from the underside of the Boeing 787 Dreamliner, acts as an emergency archive generator. It is automatically deployed when both engines lose power or if all three hydraulic systems register critically low pressure, providing limited power to maintain basic flights.
“The deployment of the RAM air turbine (rats) strongly supports the conclusion that both engines have failed,” said G -n Pruchnicki.
The Boeing 787 pilot explained why he thinks the landing equipment has not been withdrawn.
“Nowadays, every time I take off at 787, I notice the process of landing on the landing gear. By the time the gear handle is pulled, we are already about 200 feet (60.9 m), and the whole process of retracting the gear ends by about 400 feet – about eight seconds.”
The pilot believes that the one who flies did not have time to think.
“When both engines fail and the plane starts to descend, the reaction goes beyond just startled – you are tingling. At this point, the landing facilities are not your focus. Your mind is on one thing: the way of the flight. Where can I put this aircraft safe?
Investigators say the crew tried to recover, but this happened too quickly.
“The engines were switched off and then again. The pilots realized that the engines were losing thrust – probably the first restart on the left, followed to the right,” said G -H Pruknic.
“But the right engine did not have enough time to go back, and the thrust was insufficient. They were both ready to” run “, but with the left closed first, and the right one too late to recover, it was just too little, too late.”
The families and friends of the victims of the crash were eagerly awaiting the findings of the preliminary report.
When the report was finally published early on Saturday in India, IMIZZ Ali, who lost his brother, daughter-in-law, and their two young children, read carefully, just to be disappointed with what he said “read as a product description.”
“Apart from the last conversation of the pilots, there is nothing that really points to what caused the crash.”
He said he hoped more details will be publicly announced in the coming months.
“That matters to us. We want to know exactly what has happened. This will not change anything for us now, we continue to grieve – just as we have from that day.
“But at least we’ll have some answers,” Ali said.