Air India replaced the critical Throttle Control Module (TCM) which houses the fuel control switches—twice on the Boeing 787‑8 Dreamliner (VT‑ANB) that crashed. The first replacement occurred in 2019, and the second in 2023, in compliance with Boeing’s Maintenance Planning Document scheduling changes every 24,000 flight hours. Investigators note both replacements followed protocol and found no direct fault with the TCM.
In the preliminary AAIB report, cockpit voice recordings revealed that the fuel control switches unexpectedly moved to “CUTOFF” just seconds after takeoff from Ahmedabad on June 12. The two fuel switches cut off within a one-second gap, disabling both engines and causing immediate loss of altitude. Crews moved the switches back to “RUN,” but engine power briefly returned before fully failing and leading to the crash.
Following the AAIB’s early findings, the FAA issued a Continued Airworthiness Notification on July 11, affirming that the fuel switch design remains safe. Boeing followed suit in a Multi‑Operator Message, advising no urgent safety action. Both agencies maintain the fuel switch locks present no unsafe condition.
The AAIB report also referenced a 2018 FAA advisory: operators could inspect the locking mechanism of the fuel cutoff switches to prevent inadvertent activation. The advisory was non-mandatory, and Air India opted not to perform the inspection. Maintenance records confirm that Air India complied with all mandatory airworthiness directives and service bulletins.
Investigators emphasize that the TCM replacements bore no relation to known defects in the switches. The root cause behind the switches moving to “CUTOFF” remains unclear. The full accident report will arrive in the coming months to clarify whether mechanical failure, human error, or design flaw caused the malfunction.
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Authorities continue to dig deeper. The AAIB will analyze component history, maintenance logs, and switch behavior. Meanwhile, Boeing and international regulators await further evidence.