The audio cab is deepening the secret of the flight 171 accidents

Investigators found a cold opening in the preliminary investigation of the Air India 171 flight accident, which killed 260 people in June.

In just seconds after takeoff, both 12-year-old Boeing 787 Dreamliner fuel switches sharply switched to the “cutting off” position, starving fuel engines and causing overall power loss. The transition to the “compartment” is a step is usually taken only after planting.

The record of the voice of the cab is fixed by one pilot, asking another why he “made an shutdown”, to which the person replies that no. The record does not specify who said that. At the time of takeoff, the pilot flew on the plane while the captain was monitoring.

The switches were returned to a normal flight position, causing an automatic engine. At the time of the catastrophe, one engine resumed the craving and the other was relit, but not yet resumed power.

Air India 171 flight was in the air less than 40 seconds Before crashing into a crowded neighborhood In the Western Indian city of Ahmedabad, which marks one of India’s most affected aviation disasters.

Investigators conduct a check of the records of debris and cabin to understand what went wrong after takeoff. Air India’s flight rose to 625 feet in clear weather before losing location in 50 seconds, for Flightradar24. A 15-page report on Saturday offers early ideas.

Investigation – led by Indian authorities, with experts from Boeing, GE, Air India and Indian regulators, as well as participants of the National Council for Transport and UK – also raises a number of questions.

Investigators say that the closed fuel switches are intended to prevent random activation – they need to be pulling out to unlock before turning over the 1950 safety function. Built to demanding standards, they are very reliable. Protective protective fuses further protect them from random irregularities.

“It would be practically impossible to pull both switches with one hand, and it does a random deployment unlikely,” said the BBC, which is based in Canada who wanted to remain unnamed.

This is what does Air India stand out.

“This raises the question: why the pilot, which is a pilot, actually pushed the switch to the Office,” said Sean Pruchnytsky, a former airline investigator and an aviation expert in Ohio.

“Was it intentionally or the result of confusion? It seems unlikely, because the pilots reported nothing unusual. In many emergencies, the pilots could press the wrong buttons or make the wrong choice – but there were no signs of such a situation, no discussion that suggests that fuel switches were chosen.

Peter Goltz, a former head of the NTSB USA, repeated similar sentiments: “The conclusion is very disturbing – that the pilot turned off the fuel in seconds after the flight.”

“The cabin’s recorder is probably much more than what has shared. Lonely note like” why you cut off switch “is not enough,” he said.

“The new details suggest that someone in the cab has closed these valves. The question is in who and why? Both switch were disabled and then restarted for seconds. The vocal voice recorder would find more: did the pilot tried to restart the engines or monitor?”

Investigators believe that the voice voice recorder in the cabin – with an audio with pilot chips, radio messages and sounds of the cabin – contains the key to this puzzle.

“They have not yet determined the voices that are crucial. Usually, when the voice voice recorder is considered, people familiar with pilots are present to help match the votes. While we still don’t know which pilot has disconnected the switch and back,” Gelz said.

In short, investigators say it is necessary – it is a clear identification of the voice, a complete transcript of the cabin with labeled speakers, and a careful examination of all communications from the moment the plane was pushed back from the gate to the time when it crashed.

They also say that this emphasizes the need for the cabin video as recommended by NTSB. The crying appearance will be shown whose hand was on the switch.

Before planting on a flight 171, both pilots and crew underwent breathing tests and were cleaned in accordance with the flight, the report said. The pilots based in Mumbai arrived in Ahmedabad the day before the flight and had a proper vacation.

But investigators are also zero in what they describe is an interesting point in the report.

In December 2018, the US Federal Aviation Administration issued a special information newsletter (SAIB), emphasizing that some Boeing 737 fuel switches were installed with the blocked function.

While the issue was noted, it was not considered a dangerous condition that requires a conscientious (AD) directive – legally fulfilled regulation to correct the dangerous conditions in the product.

The same switch design is used in Boeing 787-8 aircraft, including VT-Anb Air India that crashed. Since Saib was advisory, Air India did not carry out the recommended checks.

Mr. The rope said he was interested in whether there was a problem with fuel switch.

“What does this mean (the bit in the report)? Does this mean that with one lapel this switch can close the engine and cut the fuel supply? If the lock function is shut off? Can the switch just drop and stop the engine? If in this case it is a really serious problem. If not, it should also be explained,” he said.

Others, however, are not convinced that this is a key question.

“I haven’t heard about this, which seems to be a low profile issue of FAA. And I have not heard any complaints (about fuel switch) from the pilots – which are usually expressed quickly. It should be studied because it is mentioned, but it may just be a distraction,” Mr. Goltz said.

Captain Kishor Puty, a former investigator of the Indian Aviation Investigation Bureau (AAIB), thinks whether the switches are switched with a problem with an electronic aircraft control unit.

“Can the fuel shutter be disputed in the electronic plane control unit without the pilot movement? If the fuel shuts electronically, it causes concern,” he said BBC.

The report states that fuel samples were “satisfactory” by fuel reservoirs. Previously, experts offered fuel pollution as a possible double engine failure. In particular, no recommendations for the Boeing 787 or its Genx-1B engines have been issued, and mechanical failure is still off before further investigation.

It also states that the Ram Air Air Air Air Air Turbine has unfolded – a clear sign of the main refusal system – and the landing transfer was found in “position down” or not involved.

A rat, a small screw that spreads from the lower side of the Boeing 787 Dreamliner, acts as a backup generator. It is automatically deployed in flight when both engines lose power or when all three hydraulic systems register critically low pressure, providing limited capacity to keep the flight system necessary.

“The deployment of Ram Air (RAT) operative turbine (RAT) is the conclusion that both engines have failed,” Mr. Pruchnytsky said.

The Boeing 787 pilot explained why he thought the landing show would not be allocated.

“These days, every time I take off at 787, I notice that the transmission process is careful. As long as the gear handle stretches, we are already 200 feet (60.9 m), and the whole process of transmission is completed by about 400 feet – about eight seconds, thanks to the hydraulic system.”

The pilot suggests that one flight did not have time to think.

“When both engines fail and the aircraft begins to decline, the reaction goes beyond just surprise – you are numb. At this point, the target gear is not the center of attention. Your mind goes on one thing: the way of flight. Where can I put this plane safely?

Investigators say the crew tried to recover, but it happened too fast.

“The engines were expelled and then back. The pilots realized that the engines were losing the craving – most likely, restarting the left at first, after which the case,” Mr.

“But the right engine lacked the time to back up the backup, and the thrust was insufficient. After all, both were tuned to” run “, but with the left closed first and the right too late to recover, it was just too little, too late.”