New information has emerged following an investigation into doomed Air India Flight AI171, including a warning the operator was given six years earlier.
The London-bound Boeing 787-8 Dreamliner crashed into a densely populated residential area of Ahmedabad, western India, on 12 June, killing 241 of the 242 people on board and 19 people on the ground.
Only one person who was on board the plane survived - 40-year-old British national Vishwashkumar Ramesh, who was seated in 11A.
An investigation to determine the cause of the crash is currently underway, with the Indian Aircraft Accident Investigation Bureau’s (AAIB) 15-page preliminary report stating that both of the aircraft’s engine fuel cutoff switches — critical controls used to start or stop fuel flow — were manually flipped from “RUN” to “CUTOFF” shortly after the plane reached an airspeed of 180 knots.
According to BBC News, the two switches were toggled just one second apart, with the report stating: "The aircraft achieved the maximum recorded airspeed of 180 Knots IAS at about 08:08:42 UTC and immediately thereafter, the Engine 1 and Engine 2 fuel cutoff switches transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec."
This action instantly cut the engines' fuel supply, causing a near-total loss of thrust.
Now, it has emerged that Air India was warned about the wrongly installed fuel switches over six years before the fatal crash cost the lives of 260 people in total.
According to the Daily Mail, the report stated that the switches' "locking feature" meant pilots had to lift them up before changing their position, but the Federal Aviation Administration (FAA) had warned airlines in December 2018 that fuel switches had been installed in some Boeing 737s "with the locking feature disengaged".
The FAA warned in a Special Airworthiness Information Bulletin: "If the locking feature is disengaged, the switch can be moved between the two positions without lifting the switch during transition, and the switch would be exposed to the potential of inadvertent operation.
"Inadvertent operation of the switch could result in an unintended consequence, such as an in-flight engine shutdown."
It recommended that the switches be inspected to see "whether the fuel control switch can be moved between the two positions without lifting up the switch."
Air India has reportedly suggested that those inspections were not carried out at the time as the bulletin from the FAA was "advisory and not mandatory".
The report also highlighted that maintenance records for the aircraft showed that the throttle control module - the part of the cockpit which includes the two fuel switches - was replaced in 2019 and 2023.
It added that the decision was not linked to the switches and no defects were found with them in the last two years.
An Air India spokesman said: "Air India stands in solidarity with the families and those affected by the AI171 accident.
"We continue to fully co-operate with the Aircraft Accident Investigation Bureau and other authorities as their investigation progresses."
The IAAB report revealed that seconds after take-off, both of the fuel control switches were moved to the "cut-off" position, triggering a total loss of power.
It added that one of the pilots was heard on the voice recorder asking the other why he'd cut off the fuel supply, to which the second replied that he had not done so.
The report states that seconds before the crash, the pilots - Captain Sumeet Sabharwal, 56, who had clocked up 15,638 flying hours, while Clive Kunder, 32, had 3,403 - returned to fuel switches to "run" and two systems tried to "relight" both engines.
A Mayday call was then issued and moments later - before the engines had a chance to restart - the plane crashed into a medical hostel below.
Dr Mario Donadi, a friend of Dr Prateek Joshi, a radiologist at the Royal Derby Hospital, who was killed in the crash alongside his wife and three children, condemned the likely cause of the horrifying accident.
He told BBC Radio 4's Today programme: "How [can] something so trivial [as] a simple switch being deactivated lead to such a loss of life, of huge dreams?"
Badasab Syed, 59, whose brother, sister-in-law and their two children were killed in the crash, added: "The report mentions the pilots discussing who turned off fuel and a possible issue with the fuel control switch. We don't know what that means. Was it avoidable?"