PETALING JAYA: The Federal Aviation Administration (FAA) in the United States had issued a bulletin on the potential disengagement of the fuel control switch locking, says India’s Aircraft Accident Investigation Bureau (AAIB).
In its preliminary report into the June 12 crash of Air India Flight 171 in Ahmedabad, the AAIB said that the Special Airworthiness Information Bulletin (SAIB) was issued following reports from operators of another type of Boeing aircraft, the 737.
“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 an airworthiness directive (AD) by the FAA,” said the AAIB in its preliminary incident report issued on Saturday (July 12).
It added that the fuel control switch design – including the locking feature - is similar on various Boeing airplane models – including a part fitted in the Boeing 787-8 airliner involved in the Air India crash.
“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 the aircraft in 2019 and 2023,” it said in the report.
“However, the reason for the replacement was not linked to the fuel control switch. There has been no defect reported pertaining to the fuel control switch since 2023,” it added.
In the report, the AAIB had said that fuel control switches to the engines of the aircraft in the crash that killed 260 people had been moved from the "run" to the "cutoff" position moments before impact.
The AAIB 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.
The Boeing 787-8 Dreamliner was headed from Ahmedabad in western India to London when it crashed, killing all but one of the 242 people on board as well as 19 people on the ground.
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".
"In the cockpit voice recording, one of the pilots is heard asking the other why the fuel was cut off. The other pilot responded that he did not do so," it said.
The aircraft quickly began to lose altitude.
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 AAIB added in its report.
The plane was carrying 230 passengers - 169 Indians, 53 British, seven Portuguese and a Canadian - along with 12 crewmembers.
Dozens of people on the ground were injured.
One passenger survived, a British citizen who was seen walking out of the wreckage of the crash, and who has since been discharged from hospital.
