Seven years ago, US regulator had flagged fuel switch issue

India’s aviation safety investigators have ruled out any defect in the fuel control switch of the Air India aircraft that crashed in Ahmedabad last month, even as the probe highlighted that the US Federal Aviation Administration (FAA) had issued a cautionary bulletin regarding the same component seven years ago.

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The Aircraft Accident Investigation Bureau (AAIB), in its preliminary report released Saturday, said the Boeing 787-8 (VT-ANB) was equipped with fuel control switches flagged by the FAA in December 2018 for "potential disengagement of the locking feature".

“The FAA had issued Special Airworthiness Information Bulletin (SAIB) No. NM-18-33 on December 17, 2018, regarding potential disengagement of the fuel control switch locking feature,” the AAIB report noted.

The FAA advisory applied to switches with part number 4TL837-3D — the same design used on the ill-fated Air India aircraft. However, Air India informed investigators that the inspections recommended in the FAA bulletin were not carried out, as these were classified as "non-mandatory guidance" rather than an airworthiness directive.

Despite this, the AAIB report clarified that maintenance records for aircraft showed no reported defects linked to the fuel control switch, either before or after throttle control module replacements in 2019 and 2023.

Investigators confirmed that during the crash sequence, both engines’ fuel switches moved from "run" to "cutoff" seconds after takeoff, leading to a dual engine shutdown. While the cause of the unintended cutoff remains under investigation, the AAIB has officially ruled out any mechanical fault in the fuel control switches themselves. The probe continues to explore other possible factors.