Fuel control switches to the engines of an Air India flight that crashed shortly after takeoff, killing 260 people, were moved from the “run” to the “cutoff” position moments before impact, a preliminary investigation report said early Saturday.
The report, issued by India’s Aircraft Accident Investigation Bureau (AAIB), said that the US Federal Aviation Administration (FAA) had issued an information bulletin in 2018 about “the potential disengagement of the fuel control switch locking feature”.
Though the concern was not considered an “unsafe condition” that would warrant a more serious directive, Air India told investigators it did not carry out suggested inspections as they were “advisory and not mandatory”.
Fuel control switches regulate the flow of fuel into an aircraft’s engines.
Air India Boeing 787-8 Dreamliner was headed from Ahmedabad to London when it crashed, killing all but one of the 242 people on board as well as 19 people on the ground.
“The FAA issued Special Airworthiness Information Bulletin (SAIB) No. NM-18-33 on December 17, 2018, regarding the potential disengagement of the fuel control switch locking feature,” said the preliminary report.
Air India was compliant with all airworthiness directives and alert service bulletins on the aircraft, the report said.
“This SAIB was issued based on reports from operators of Model 737 airplanes that the fuel control switches were installed with the locking feature disengaged. The airworthiness concern was not considered an unsafe condition that would warrant airworthiness directive (AD) by the FAA,” it said.
“As per the information from Air India, the suggested inspections were not carried out as the SAIB was advisory and not mandatory. The scrutiny of maintenance records revealed that the throttle control module was replaced on VT-ANB in 2019 and 2023,” it added.
The fuel switch has two positions — ‘RUN’ and ‘CUT OFF’ — and are used to start or shut down engines.
In its 15-page report, the investigation bureau said that once the aircraft achieved its top recorded speed, “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”.
The switches then returned to the “RUN” position and the engines appeared to be gathering power, but “one of the pilots transmitted ‘MAYDAY MAYDAY MAYDAY'”, the report said.
The report did not offer any conclusions or apportion blame for the June 12 disaster, but indicated that one pilot asked the other why he cut off fuel, and the second pilot responded that he had not.
Boeing said in a statement it will “continue to support the investigation and our customer”, adding “our thoughts remain” with those affected by the disaster.
Air India said it was “working closely with stakeholders, including regulators.”
“We continue to fully cooperate with the AAIB and other authorities as their investigation progresses,” it said in a statement on X.