How the fuel switches of the Boeing aircraft indicated in the Air India accident operate

The disaster of flight 171 to London, the United Kingdom, was one of the worst aviation accidents worldwide in almost a decade.

The switches that control the fuel flow to the engines of the plane moved from the state of “operation” to the “cut”, which hindered the impulse of the ship, according to the preliminary report, published by the Division of Air Accident Research of India (AAIB).

The aforementioned switches control the fuel flow to the plane engines.

They are normally used to start the engines before taking off and to turn them off after landing.

They are not usually used during the flight. The immediate effect of moving them from the “operation” position to that of “Court” is that the power of the plane is cut, something especially dangerous during the first seconds of the ascent, as was the case of the Air India flight.

The only reason to do so during the flight is in case of emergency; For example, if there is a fire or engine failure.

The switches are designed so that they do not move accidentally. They have insurance.

They are located in the center of the cabin, in the middle of the two pilots and under the thrust or acceleration levers.

At the moment, it is unknown why these switches went out after the take -off of the flight to London on June 12.

In the preliminary report published on Friday, the researchers referred to a 2018 FAA notice, which urged, but did not force Boeing models to inspect the switch blocking mechanism that cut the fuel to ensure that they did not move accidentally.

Air India did not take this measure, according to the AAIB in its preliminary conclusions.

FAA declared civil aviation authorities on Friday that I had seen the preliminary report of the AAIB.

The US agency indicated that its own 2018 notice “was based on reports that the fuel control switches were installed with the deactivated blocking mechanism,” but added that it does not believe that this makes the planes be insecure.

“Although the design of the fuel control switch, including the blocking mechanism, is similar in several models of Boeing aircraft, FAA does not consider that this problem is an insecure condition that justifies an aircraft directive for any Boeing plane model, including model 787,” the authority declared in an internal note shared with the BBC.

The AAIB, which reviewed the voice recordings of the cabin, reported that during the flight one pilot was heard asking the other why he had cut the fuel.

It is not clear who said what in the audio. But at the time of takeoff, the co -pilot was the one who wore the aircraft while the captain supervised.

“The other pilot replied that he had not done it,” the document stands out.

The researchers said that the fuel switches almost simultaneously changed the operating position to the court just after takeoff, but the reasons are unknown.

Changing to “cut” is an action that is normally performed only after landing.

Air India 171 was in the air less than 40 seconds before crashing into a neighborhood full of people in the city of Ahmedabad.

It amounted to 190 meters with good weather before their location data were lost to 50 seconds, according to Flightradar24.

The aircraft crashed into the structure of a medical school near the airport and caused the death of 260 people, mostly passengers.

A British citizen survived the accident.

He planned to fly from Indian territory to the Gatwick London airport.

Even the remains of the plane are under investigation, as well as the recordings of the cabin to understand what failed just after takeoff.

The 15 -page report offers preliminary information.

Researchers are expected to present more detailed information in 12 months.

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